WO2019156133A1 - Carbon-containing powder, separation method, and use of carbon-containing powder - Google Patents
Carbon-containing powder, separation method, and use of carbon-containing powder Download PDFInfo
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- WO2019156133A1 WO2019156133A1 PCT/JP2019/004308 JP2019004308W WO2019156133A1 WO 2019156133 A1 WO2019156133 A1 WO 2019156133A1 JP 2019004308 W JP2019004308 W JP 2019004308W WO 2019156133 A1 WO2019156133 A1 WO 2019156133A1
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
- B03B—SEPARATING SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS
- B03B5/00—Washing granular, powdered or lumpy materials; Wet separating
- B03B5/28—Washing granular, powdered or lumpy materials; Wet separating by sink-float separation
- B03B5/30—Washing granular, powdered or lumpy materials; Wet separating by sink-float separation using heavy liquids or suspensions
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B32/00—Carbon; Compounds thereof
- C01B32/05—Preparation or purification of carbon not covered by groups C01B32/15, C01B32/20, C01B32/25, C01B32/30
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B32/00—Carbon; Compounds thereof
- C01B32/20—Graphite
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- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B18/00—Use of agglomerated or waste materials or refuse as fillers for mortars, concrete or artificial stone; Treatment of agglomerated or waste materials or refuse, specially adapted to enhance their filling properties in mortars, concrete or artificial stone
- C04B18/04—Waste materials; Refuse
- C04B18/06—Combustion residues, e.g. purification products of smoke, fumes or exhaust gases
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W30/00—Technologies for solid waste management
- Y02W30/50—Reuse, recycling or recovery technologies
- Y02W30/91—Use of waste materials as fillers for mortars or concrete
Definitions
- the present invention relates to a carbon-containing powder.
- fly ash generated during power generation at coal-fired thermal power plants is recycled into concrete raw materials, building material raw materials, cement raw materials, and the like.
- the fly ash contains ash composed of a metal oxide such as Al 2 O 3 or SiO 2 and unburned carbon that is a carbon component that remains unburned. For this reason, in order to use it as a building material raw material, a concrete raw material (admixture), etc., it is preferable to separate unburned carbon contained in fly ash and reduce the unburned carbon concentration.
- an electrostatic separation method or a flotation method is known as a method for separating unburned carbon in fly ash.
- the electrostatic separation method is a method in which fly ash is introduced into parallel plate electrodes in a dry state to attract and separate charged unburned carbon toward the positive electrode side.
- the flotation method is to attach unburned carbon particles to micro air generated using a foaming agent in a slurry of fly ash through a scavenger such as kerosene. It is a method of floating and separating.
- Patent Document 1 discloses a method for removing unburned carbon in fly ash by flotation.
- the fly ash that has been slurried by adding water is stirred to generate active energy on the surface of the unburned carbon particles, thereby making the unburned carbon particles oleophilic. (Hydrophobic).
- a trapping agent such as kerosene and light oil and a foaming agent are added to the slurry containing the oleophilic unburnt carbon, and the trapping agent is attached to the unburned carbon and unburned carbon is generated in the generated bubbles. Flotation with the attached.
- the flotation method in which the unburned carbon contained in the fly ash is floated by adhering to the bubbles as described in Patent Document 1 has a problem that the separation speed is slow and the separation efficiency is poor. For this reason, since many fine particles of metal oxide remain in the separated unburned carbon, it is difficult to separate and recover only unburned carbon with a high carbon content. Furthermore, fine particles of metal oxides such as SiO 2 and Al 2 O 3 tend to agglomerate with other particles due to attractive forces such as van der Waals force and electrostatic force in the dry state. Will also adhere. For this reason, it was much more difficult to properly separate the unburned carbon particles and the fine metal oxide particles contained in the fly ash.
- an object of the present invention is to provide a new and improved carbon-containing powder, a separation method, and a method of using the carbon-containing powder.
- a carbon-containing powder containing carbon particles and oxide particles The carbon component content in the carbon-containing powder is 50% by mass or more and 95% by mass or less,
- the oxide particles are particles composed of a compound containing one or both one of the SiO 2 component or Al 2 O 3 component, the total of the said SiO 2 component Al 2 O 3 component of the oxide particles The content of is 75% by mass or more,
- the carbon particles are porous particles in which a plurality of pores are formed,
- a carbon-containing powder is provided in which at least part of the oxide particles are present in the pores of the carbon particles.
- the content of the carbon component in the carbon-containing powder may be 70% by mass or more and 95% by mass or less.
- the N / C ratio which is the mass ratio between the nitrogen component contained in the carbon-containing powder and the carbon component, may be more than 0 and 0.02 or less.
- the particle diameter of the oxide particles may be 1 to 20 ⁇ m with a volume-based 50% particle diameter.
- the average value of the circularity of the oxide particles may be more than 0.9 and 1 or less.
- the content of the SiO 2 component in the oxide particles is 50% by mass or more and 80% by mass or less,
- the content of the Al 2 O 3 component in the oxide particles, 10 mass% or more, may be is 30 mass% or less.
- the carbon-containing powder may have a specific surface area of 50 to 300 m 2 / g.
- a separation method for separating carbon particles and oxide particles from a mixture of carbon particles and oxide particles derived from fly ash A mixing step of mixing the mixture, water, and a hydrophobic liquid having a specific gravity greater than that of the water to produce a mixture; A specific gravity separation step of separating the carbon particles and the oxide particles by allowing the mixed liquid to stand and separating the mixture into a hydrophobic liquid phase containing the carbon particles and an aqueous phase containing the oxide particles; A separation method is provided.
- a first recovery step of recovering the oxide particles by separating the water from the aqueous phase separated in the specific gravity separation step may be further included.
- the carbon-containing powder contains the carbon particles and the oxide particles,
- the carbon component content in the carbon-containing powder is 50% by mass or more and 95% by mass or less
- the oxide particles are particles composed of a compound containing one or both one of the SiO 2 component or Al 2 O 3 component, the total of the said SiO 2 component Al 2 O 3 component of the oxide particles The content of is 75% by mass or more,
- the carbon particles are porous particles in which a plurality of pores are formed, At least a part of the oxide particles may be present in the pores of the carbon particles.
- the N / C ratio which is the mass ratio between the nitrogen component contained in the carbon-containing powder and the carbon component, may be 0.02 or less.
- the combination of the mixing step and the specific gravity separation step may be repeated in multiple stages by a countercurrent type multi-stage continuous process.
- a pulverization process for pulverizing the carbon particles contained in the liquid mixture may be further included by performing a pulverization process on the liquid mixture of either or both of the hydrophobic liquid and water and the mixture. .
- the carbon particles contained in the mixed solution may be pulverized by a pulverization process using beads.
- the fly ash is produced by burning coal
- the carbon particles are unburned carbon particles left unburned during the combustion
- the oxide particles may be particles in which the coal ash is melted and granulated during the combustion.
- the specific gravity separation step includes: A rough separation step of separating the liquid mixture into a hydrophobic liquid phase containing the carbon particles and an aqueous phase containing the oxide particles by allowing the mixture to stand. Water is added to and mixed with the hydrophobic liquid phase separated in the rough separation step, and the liquid mixture of the hydrophobic liquid phase and water is allowed to stand, whereby the hydrophobic liquid phase containing the carbon particles, A water washing step for separating into an aqueous phase containing the oxide particles; May be included.
- a method for using carbon-containing powder wherein the carbon-containing powder is used as an alternative to coal used in a sintering machine, a combustion furnace or a converter, or as an SO 2 adsorbent or denitration material.
- the carbon-containing powder may be used after mixing the carbon-containing powder with another powder to increase the bulk specific gravity of the carbon-containing powder.
- a new and improved carbon-containing powder, a separation method, and a method of using the carbon-containing powder can be provided.
- fly ash is a kind of coal ash generated by the combustion of coal.
- fly ash is generated by burning fuel coal in a boiler or the like of a power plant.
- Bituminous coal or subbituminous coal is mainly used as fuel coal at power plants.
- the fly ash contains unburned carbon (carbon component), which is a carbon component left unburned, together with a metal oxide (ash) made of a compound containing an Al 2 O 3 component, an SiO 2 component, and the like.
- carbon content in the fly ash (carbon component content) is 1.5 to 15% by mass, and the content of metal oxides such as SiO 2 component and Al 2 O 3 component is 75 to 98% by mass. .
- the substantially spherical shape here is not limited to a true spherical shape, and may be any shape that has almost no irregularities on the surface and is almost similar to a sphere, and includes shapes such as an ellipsoidal shape and a polygonal spherical shape.
- the particle diameter of the oxide particles is generally 200 ⁇ m or less, and oxide particles having a diameter of less than 1 ⁇ m are often included in an amount of 5 to 10% by mass.
- fly ash is substantially spherical and contains a lot of solid oxide particles, so the specific surface area of fly ash is as small as 0.5 to 10 m 2 / g.
- the fly ash has a particle size of about 1 to 200 ⁇ m.
- Non-patent Document 1 Tsuyoshi Yukimoto, 3 others, “Difference between coal and coke”, Ministry of Finance Customs Central Analysis Bulletin, Vol. 49 pp. 69-76, March 19, 2011
- the present inventor uses a special wet separation method to suitably separate the unburned carbon particles in the fly ash from the oxide particles, and the carbon containing enriched unburned carbon particles.
- a method for producing the powder was found, and the characteristics of the carbon-containing powder produced by the method were investigated and analyzed, and various new characteristics were found.
- fly ash coal ash
- the fly ash contains unburned carbon particles (carbon component) and oxide particles (ash) composed of a compound containing SiO 2 component, Al 2 O 3 component, etc., but FIG. 1A and FIG. 1B ( Hereinafter, as shown in FIG. 1), the unburned carbon particles P2 were porous particles, and it was found that a large number of pores P20 were formed on the surface layer of the unburned carbon particles P2. .
- the oxide particles P1 are substantially spherical solid particles, and may be attached to the surface of the unburned carbon particles P2, or may be a plurality of pores P20 formed in the surface layer of the unburned carbon particles P2. It has been found that there are cases where it exists inside of.
- the carbon-containing powder according to this embodiment in order to separate and concentrate the unburned carbon particles P2 from the fly ash in which the unburned carbon particles P2 and the oxide particles P1 are mixed, the carbon-containing powder according to this embodiment is used.
- the following special wet separation method is used.
- a liquid mixture obtained by mixing and stirring water, a hydrophobic liquid (for example, an organic solvent having hydrophobicity), and fly ash is allowed to stand, so that a hydrophobic liquid phase containing unburned carbon particles P2 is oxidized. It isolate
- the cake containing unburned carbon particles P2 is recovered by separating the hydrophobic liquid from the hydrophobic liquid phase (solid-liquid separation step). Thereafter, the cake is heated to volatilize the hydrophobic liquid, thereby collecting the carbon-containing powder in which the unburned carbon particles P2 are concentrated (recovery step).
- unburned carbon particles P2 can be separated and concentrated from fly ash to obtain a carbon-containing powder having a high carbon content (carbon content: 50% by mass or more).
- this separation method as shown in FIGS. 2A and 2B (hereinafter collectively referred to as FIG. 2), the fine oxide particles P1 entering the pores P20 of the unburned carbon particles P2 are not so much removed. Most of the oxide particles P1 adhering to the surface of the unburned carbon particles P2 can be separated and removed.
- the pulverization process it is preferable to pulverize the mixed liquid of either one or both of the water and the hydrophobic liquid and fly ash in the pre-process or post-process of the specific gravity separation process (pulverization process).
- the pulverization method include a pulverization process using ultrasonic waves, a pulverization process using a high-speed shear mixer, and a pulverization process using a ball mill or a bead mill.
- the hydrophobic liquid used in the pulverization step may be the same as or different from the hydrophobic liquid L2 used in the specific gravity separation step.
- the unburned carbon particles P2 in the fly ash are pulverized and divided into a plurality of pieces at the fracture surface P21. Is done. Thereby, the substantially spherical oxide particles P1 that have entered the pores P20 near the fracture surface P21 are released from the pores P20. Therefore, not only the oxide particles P1 that have adhered to the surface of the unburned carbon particles P2, but also the oxide particles P1 that have entered the pores P20 are separated and removed from the unburned carbon particles P2.
- the fuel carbon particles P2 and the oxide particles P1 can be more preferably separated. Thereby, it becomes possible to obtain a carbon-containing powder (carbon content: 70% by mass or more) having an even higher carbon content by subjecting fly ash to pulverization.
- N / C ratio is a mass ratio between the amount of nitrogen component (nitrogen content) and the amount of carbon component (carbon content) in a certain material. It is obtained by dividing by the content rate. Since the carbon-containing powder according to this embodiment has a low nitrogen content and a high carbon content, the N / C ratio of the carbon-containing powder is more than 0 and 0.02 or less. It is within the range of 0065 to 0.0196. Although not described in Table 1, the N / C ratio of anthracite, bituminous coal, and sub-bituminous coal is, for example, 0.008 to 0.03, but many of them are over 0.02.
- the N / C ratio of the carbon-containing powder according to the present embodiment corresponds to a low region among the N / C ratios of anthracite, bituminous coal, and sub-bituminous coal.
- the N / C ratio of the unburned carbon contained in the original fly ash before the wet separation process according to this embodiment is 0.02 or less, and the nitrogen content is low.
- the N / C ratio of the carbon-containing powder mainly composed of unburned carbon separated and recovered is also 0.02 or less. As will be described later, it is considered that the N / C ratio decreases as the combustion temperature in the boiler of the power plant increases.
- carbon content C A of the carbon-containing powder is recovered by a wet separation from the fly ash by the production method according to the carbon content present embodiment is preferably 50 mass% or more and 95 mass% or less.
- the carbon content C A of the carbon-containing powder is recovered by a production method comprising the above grinding process, 70 mass% or more and 95 mass% or less.
- the N / C ratio is more preferably 0.015 or less for effective use as an alternative to low nitrogen coal used in a sintering machine. For this reason, the production method according to the present embodiment makes it possible to collect and recycle carbon-containing powder having a high carbon content rate as low as low nitrogen coal and a low N / C ratio from fly ash. Important and beneficial to.
- the unburned carbon particle P2 contained in the carbon containing powder which concerns on this embodiment is a porous particle by which many pores P20 were formed in the surface layer.
- the specific surface area of the carbon-containing powder according to the present embodiment is 50 to 300 m 2 / g equivalent to the activated coke powder, and the specific surface area of the fly ash before the separation treatment (0.5 to 10 m 2 / g) It is several tens to one hundred times larger than that.
- the specific surface area of the carbon-containing powder according to the present embodiment is as large as 50 to 300 m 2 / g. For this reason, the carbon-containing powder according to the present embodiment has SO 2 adsorption capacity and denitration capacity, and can be effectively used as an SO 2 adsorption material and denitration material.
- the oxide particles P1 are particles made of a compound containing at least one of or both of a SiO 2 component and an Al 2 O 3 component.
- Si and Al are mainly contained as compounds such as mullite (Al 6 Si 2 O 13 ), quartz (SiO 2 ), and amorphous (nAl 2 O 3 .mSiO 2 ).
- n and m are positive numbers. These compounds correspond to the SiO 2 component or the Al 2 O 3 component.
- the fly ash contains oxide particles P1 made of such a compound. For this reason, the carbon-containing powder separated from the fly ash also contains the remaining oxide particles P1 made of the compound.
- the carbon-containing powder according to the present embodiment is a powder mainly composed of unburned carbon (carbon component), but also contains oxide particles P1 that could not be separated by the specific gravity separation process described later.
- the content rate of the oxide particles P1 in the carbon-containing powder is less than 50% by mass, preferably less than 30% by mass.
- the total content of the SiO 2 component and the Al 2 O 3 component in the oxide particles P1 is 75% by mass or more and 98% by mass or less.
- the oxide particles P1 but a compound consisting mainly of SiO 2 component and Al 2 O 3 component may contain oxides of other elements besides that.
- the content of the SiO 2 component in the oxide particles P1 is 50% by mass or more and 80% by mass or less, and the content of the Al 2 O 3 component in the oxide particles P1 is 10% by mass or more, 30%. It is below mass%.
- the average content rate is obtained by measuring the content rates of the SiO 2 component and the Al 2 O 3 component using a sample of the plurality of oxide particles P1, and calculating the average of the plurality of measured values.
- the carbon-containing powder according to the present embodiment contains not only unburned carbon particles P2 but also oxide particles P1.
- These oxide particles P1 are particles that are cooled and granular after coal ash is melted by combustion heat when the coal is burned in a boiler or the like as described above, and are almost solid solid particles. It is.
- the particle diameter of the oxide particles P1 is 1 to 20 ⁇ m in terms of a 50% particle diameter (median diameter D50) based on volume.
- the average value of the circularity of the oxide particles P1 is more than 0.9 and 1 or less.
- the circularity of the particle is the ratio of the circumference of a circle having the same area as the projected image of the particle to the circumference of the projected image of the particle.
- At least a part of the oxide particles P1 is present in a large number of pores P20 formed in the surface layer of the unburned carbon particles P2.
- the content of the oxide particles P1 remaining in the pores P20 and the oxide particles P1 contained outside the pores P20 in the carbon-containing powder from which the oxide particles P1 are separated from the surface by the specific gravity separation process described later is It may be more than 5% by mass and less than 50% by mass.
- the carbon-containing powder according to the present embodiment has a 50% particle diameter of 1 to 20 ⁇ m in the pores P20 of the porous unburned carbon particles P2, and the average value of the circularity exceeds 0.9. 1 or less, the particulate oxide (substantially spherical oxide particles P1) is mixed.
- the carbon-containing powder having such a characteristic configuration has not been conventionally known, and can be said to be a novel and useful low nitrogen carbon powder.
- a carbon-containing powder mainly composed of porous unburned carbon particles is obtained by a gas adsorption method.
- the specific surface area (unit: m 2 / g) can be measured.
- a gas mixture of helium and nitrogen (volume ratio 7: 3) is used, and the monomolecular adsorption amount and specific surface area of the gas can be calculated using the BET equation.
- sample gas is aerated in the reaction tank at a reaction tank temperature of 150 ° C. and SV500 h ⁇ 1 for 10 hours.
- the composition of the sample gas can be NO: 200 ppm, NH 3 : 200 ppm, O 2 : 6% by volume, H 2 O: 10% by volume, and the rest can be nitrogen.
- the NO concentration and O 2 concentration in the gas discharged from the reaction tank are measured, and the NO concentration rate (volume%) due to the carbon-containing powder is obtained by calculating the rate of decrease in the NO concentration in the steady state. be able to.
- the circularity of the oxide particles P1 recovered in (6) above is analyzed using a particle image analyzer to analyze the shape of the captured oxide particles. You can ask for it.
- a suspension is prepared by adding an aqueous dispersant solution to a sample of oxide particles and dispersing the mixture with ultrasonic waves.
- oxide particles in the suspension can be captured as a still image by the sheath flow method.
- the average value of circularity may be the average circularity of a predetermined number or more of oxide particles measured in a sample.
- the number of oxide particles used for calculating the average value may be, for example, 10,000 or more.
- the content of SiO 2 can be quantitatively analyzed by a fluorescent X-ray analyzer (XRF) using a glass bead method. Specifically, a plurality of measurement samples having a known SiO 2 content rate are prepared with different content rates, and the X-ray fluorescence intensity derived from Si of the prepared measurement sample is measured by a fluorescent X-ray analyzer. . Using the obtained Si-derived fluorescent X-ray intensity and the SiO 2 content, a calibration curve showing the relationship between the SiO 2 content and the fluorescent X-ray intensity is prepared in advance.
- XRF fluorescent X-ray analyzer
- the X-ray fluorescence intensity derived from Si is measured with a fluorescent X-ray analyzer for the sample whose SiO 2 content of interest is unknown, and using the obtained fluorescent X-ray intensity and the calibration curve, SiO 2
- the content of can be specified. This makes it possible to determine the content of the SiO 2 component of the oxide particles P1 described above.
- the content of Al 2 O 3 can be quantitatively analyzed by a fluorescent X-ray analyzer (XRF) using a glass bead method. Specifically, a plurality of measurement samples having a known content ratio of Al 2 O 3 are prepared by changing the content ratio, and the fluorescence X-ray intensity derived from Al of the prepared measurement sample is measured by a fluorescent X-ray analyzer. taking measurement. Using the obtained Al-derived fluorescent X-ray intensity and the Al 2 O 3 content, a calibration curve indicating the relationship between the Al 2 O 3 content and the fluorescent X-ray intensity was prepared in advance. deep.
- XRF fluorescent X-ray analyzer
- the content of Al 2 O 3 can be specified. This makes it possible to determine the content c Al of Al 2 O 3 component of the oxide particles P1 described above.
- FIG. 4 is a process diagram showing an outline of the method for producing the carbon-containing powder P0 according to the present embodiment.
- fuel coal FC such as bituminous coal or sub-bituminous coal is burned in a boiler 4 of a thermal power plant, and as a result of this combustion, fly ash that is coal ash is produced.
- Ash FA is generated (combustion process).
- This fly ash FA is introduced into a separation and recovery device 5 (details will be described later), and oxide particles P1 made of SiO 2 component, Al 2 O 3 component, etc. by a special wet separation method according to this embodiment. (Ash content) and unburned carbon particles P2 (carbon component) are separated and recovered (separation and recovery step).
- the carbon-containing powder P0 according to the present embodiment is manufactured through the combustion process in the boiler 4 and the separation and recovery process in the separation and recovery device 5.
- the reason why the nitrogen content of the carbon-containing powder P0 according to the present embodiment is low is considered to be due to the coal combustion process in the boiler 4 as described below.
- Non-Patent Document 2 Although depending on the coal type, of the nitrogen-based gas in carbonization gas (HCN, NH 3, N 2), HCN, the generation of NH 3 begins at about 300 ° C., 800 End at around °C. On the other hand, it has been found that N 2 starts to be generated at about 600 ° C. and continues to be generated even at a high temperature of 800 ° C. or higher at which generation of other nitrogen-based gases almost ends.
- carbon-based gas CO, CH 4 , HCN
- CO CO, CH 4 , HCN
- Non-Patent Document 2 Yasuhiro Fujibe and 2 others, “Partition behavior of nitrogen in coal retorting process by real-time gas measurement and XPS measurement”, Materials and Processes, Vol. 25 No. 2, Page. ROMBUNNO. 36, September 1, 2012
- the combustion temperature in the boiler 4 of the power plant is about 1300 to 1500 ° C.
- the residence time of the coal powder in the boiler 4 is about several seconds.
- the residence time of the coal powder in the coke oven is very short, and the coal powder in the boiler 4 is in a combustion state instead of a dry distillation state.
- the nitrogen component of the coal powder is reduced because the nitrogen compound contained in the surface layer is decomposed and gasified. Therefore, since the nitrogen content of the unburned carbon particles P2 in the fly ash FA after the combustion process is lowered, it is considered that the N / C ratio of the carbon-containing powder P0 recovered by concentrating the unburned carbon particles is also lowered. It is done. Further, it is considered that the N / C ratio of the carbon-containing powder P0 decreases as the combustion temperature in the boiler 4 increases.
- the fly ash FA before the wet separation treatment contains more spherical oxide particles P1 than the unburned carbon particles P2, and is contained in the pores P20 of the unburned carbon particles P2.
- Oxide particle P1 enters and oxide particle P1 covers the surface of unburned carbon particle P2. For this reason, conventionally, the characteristics of the unburned carbon particles P2 alone were unknown.
- unburned carbon particles are obtained by a wet separation process using water and a hydrophobic liquid (see FIG. 5 described later) that is not accompanied by a pulverization process.
- P2 and oxide particles P1 are separated.
- the oxide particles P1 adhering to the surface of the unburned carbon particles P2 are removed, but the oxide particles entering the pores P20 of the unburned carbon particles P2. It is difficult to remove P1.
- either one or both of water and hydrophobic liquid cannot enter the pores P20 of the unburned carbon particles P2. It is thought that it is difficult to discharge P1.
- the carbon-containing powder containing such unburned carbon particles P2 consider the case of using as SO 2 adsorbent.
- the pores P20 of the unburned carbon particles P2 clogged with the oxide particles P1 are counted as the specific surface area of the carbon-containing powder.
- most of the exhaust gas (normal pressure) containing SO 2 or the like cannot enter the deep part of the pores P20. . Therefore, not be effectively utilized pores P20 of unburned carbon particles P2 as an adsorption surface of the SO 2, there is room for improvement in performance as SO 2 adsorbent.
- a wet separation process (see FIGS. 7 to 10 described later) is performed that involves a pulverization process of the unburned carbon particles P2.
- a pulverization treatment as shown in FIG. 3, the fragile porous unburned carbon particles P2 are easily crushed, and the plurality of pores P20 are connected at the fracture surface P21, so that the unburned carbon particles P2 are refined.
- the substantially spherical oxide particles P1 in the pores P20 can easily come into contact with either or both of water and a hydrophobic liquid, and many oxides
- the particles P1 can be discharged from the pores P20 and separated from the unburned carbon particles P2.
- a carbon-containing powder mainly composed of unburned carbon particles P2 from which the oxide particles P1 are separated is obtained.
- the carbon content increases, and the surface area of the carbon component serving as the SO 2 adsorption surface also increases. Therefore, the processing capacity of the SO 2 -containing gas by the carbon-containing powder is increased, and the performance as the SO 2 adsorbent is improved.
- the carbon-containing powder production method includes a combustion step (S0) and a separation and recovery step (S1).
- the combustion step (S0) the fuel coal FC is burned by a boiler 4 such as a thermal power plant to generate fly ash FA that is coal ash.
- the separation and recovery device 5 separates the oxide particles P1 and the unburned carbon particles P2 from the fly ash FA and recovers them.
- a mixture containing oxide particles P1 and unburned carbon particles P2 derived from fly ash FA is mixed with carbon-containing powder P0 mainly composed of unburned carbon particles P2 and oxidized. Wet-separate into product particles P1.
- water is used as an extractant for the oxide particles P1 which are hydrophilic particles, and a hydrophobic liquid having a specific gravity greater than that of water is used as an extractant for the unburned carbon particles P2 which are hydrophobic particles. use.
- the said water and hydrophobic liquid are mixed and stirred in the fly ash (solid content) FA which is a process target mixture, and the liquid mixture (1st slurry) in which the mixture was disperse
- the mixed liquid is allowed to stand in a separation apparatus (for example, a settler such as a precipitation tank or a stationary tank), and the above mixed liquid is removed from the upper aqueous phase by utilizing the specific gravity difference between water and the hydrophobic liquid.
- a separation apparatus for example, a settler such as a precipitation tank or a stationary tank
- the oxide particles P1 hydrophilic particles
- the unburned carbon particles P2 hydrophobic particles
- the oxide particles P1 are separated and recovered (first recovery step), and from the hydrophobic liquid phase (third slurry) separated in the separation step, Unburned carbon particles P2 are separated and recovered (second recovery step).
- the oxide particles P1 and the unburned carbon particles P2 can be quickly and efficiently separated, and the oxide particles P1 and the unburned carbon particles P2 having a high content can be recovered and reused.
- the hydrophobic liquid is a liquid having hydrophobicity, that is, a liquid having a property of low affinity for water (in other words, hardly dissolved in water or mixed with water).
- the hydrophobic liquid may be a liquid having a solubility in water at 20 ° C. of 0 g / L or more and 5.0 g / L or less.
- hydrophobicity in this specification is a property including lipophilicity.
- the hydrophobic liquid may be an organic solvent having hydrophobicity (hereinafter referred to as “hydrophobic solvent”) or various oils such as silicone oil.
- hydrophobic solvent for example, a fluorine-based, bromine-based or chlorine-based organic solvent can be used.
- a hydrophobic liquid Since such a hydrophobic liquid has a low affinity for water, when the mixed liquid obtained by mixing and stirring the hydrophobic liquid and water is allowed to stand, an aqueous phase mainly composed of water and a hydrophobic liquid (for example, a hydrophobic solvent) are separated. It is separated into two phases of a hydrophobic liquid phase (for example, a hydrophobic solvent phase) as a main component.
- a hydrophobic liquid phase for example, a hydrophobic solvent phase
- Table 2 shows examples of hydrophobic liquids used in the separation method according to this embodiment. All of the hydrophobic liquids exemplified in Table 2 have a specific gravity of more than 1, a solubility in water of 5.0 g / L or less, and are hydrophobic.
- the specific gravity of the hydrophobic liquid is preferably more than 1.05. Thereby, due to the difference in specific gravity between water and the hydrophobic liquid, it is possible to quickly separate into the aqueous phase and the hydrophobic liquid phase in a short time of, for example, about 1 to 30 seconds after the liquid mixture is allowed to stand.
- Hydrophilic particles are particles having an affinity for water and have a property of being more easily mixed with water than the hydrophobic liquid.
- the oxide particles P1 contained in the fly ash FA are hydrophilic particles.
- the hydrophobic particles are particles having an affinity for the hydrophobic liquid and have a property of being easily mixed in the hydrophobic liquid rather than water.
- the unburned carbon particles P2 contained in the fly ash FA are hydrophobic particles. Accordingly, in the mixed liquid of water and the hydrophobic liquid, the hydrophilic particles (oxide particles P1) move from the hydrophobic liquid phase to the aqueous phase and are mainly dispersed in the aqueous phase. On the other hand, the hydrophobic particles (unburned carbon particles P2) move from the aqueous phase to the hydrophobic liquid phase, and are mainly dispersed in the hydrophobic liquid phase.
- the specific gravity of the oxide particles P1 that are hydrophilic particles is, for example, 2.4 to 2.6.
- the specific gravity of the unburned carbon particles P2 that are hydrophobic particles is, for example, 1.3 to 1.5.
- the specific gravity of the oxide particles P1 is smaller than the specific gravity of the unburned carbon particles P2, the oxide particles P1 and the unburned carbon particles P2 are separated by wet separation using water and a hydrophobic liquid as described above. It is possible.
- the specific gravity of the particle is the specific gravity (true specific gravity) of the particle itself and not the bulk specific gravity of the particle.
- the separation and recovery step (S1) includes a specific gravity separation step (S2) and a recovery step (S4).
- the specific gravity separation step (S2) includes a rough separation step (S21) and a water washing step (S22), and the recovery step (S4) includes a solid-liquid separation step (S41) and a drying step (S42).
- fly ash FA In the coarse separation step (S21) of the specific gravity separation step (S2), fly ash FA, water L1, and hydrophobic solvent L2 are mixed. By allowing the mixture to stand, specific gravity separation into a hydrophobic solvent phase ph2 mainly containing unburned carbon particles P2 (in other words, carbon particles) as a solid content and an aqueous phase ph1 mainly containing oxide particles P1. To do.
- the unburned carbon particles P2 and the oxide particles P1 in the fly ash FA can be roughly separated. Thereby, the content rate (in other words, carbon content rate) of the unburned carbon particle P2 in the solid content in the hydrophobic solvent phase ph2 can be increased.
- water L1 is added to and mixed with the hydrophobic solvent phase ph2 separated in the coarse separation step (S21).
- specific gravity separation is performed on the hydrophobic solvent phase ph2 in which the unburned carbon particles P2 are concentrated as a solid content and the aqueous phase ph1 mainly containing the remaining oxide particles P1.
- the hydrophobic solvent phase ph2 containing the unburned carbon particles P2 is washed with water L1, and the oxide particles P1 remaining in the rough separation step (S21) are separated from the unburned carbon particles P2. Can be removed.
- the unburned carbon particles P2 contained in the hydrophobic solvent phase ph2 can be concentrated, and the content (carbon content) of the unburned carbon particles P2 in the solid content in the hydrophobic solvent phase ph2 can be further increased. .
- the water washing step (S22) may be performed only once, but by performing a plurality of times (for example, 2 to 4 times), the inclusion of unburned carbon particles P2 in the solid matter in the hydrophobic solvent phase ph2 The rate (in other words, the carbon content) can be further increased.
- the water washing step (S22) is not essential, and only the rough separation step (S21) may be performed. Even in this case, the unburned carbon particles P2 and the oxide particles P1 can be separated to some extent, and it is possible to obtain a hydrophobic solvent phase ph2 having a high content of unburned carbon particles P2.
- the hydrophobic solvent phase ph2 separated in the specific gravity separation step (S2) is separated from the liquid component by solid-liquid separation treatment such as filtration or centrifugation.
- the hydrophobic solvent L2 is separated into solid particles (mainly unburned carbon particles P2 and remaining oxide particles P1), and the hydrophobic solvent L2 is removed from the solid particles.
- the cake C2 mainly containing solid particles such as unburned carbon particles P2 is recovered.
- the boiling point of the hydrophobic solvent L2 is preferably less than 200 ° C. under atmospheric pressure, and more preferably less than 100 ° C.
- carbon-containing powder P0 mainly composed of unburned carbon particles P2 is separated and recovered from fly ash FA, and carbon.
- a carbon-containing powder P0 having a content of 50% by mass or more can be obtained.
- FIG. 6 is a schematic diagram showing the separation and recovery device 5 according to this embodiment.
- the specific gravity of the hydrophobic solvent L2 to be used is more than 1.05.
- the separation and recovery device 5 includes two sets of mixing devices (mixers 51A and 51B) and separation devices (settlers 52A and 52B) that perform the specific gravity separation step (S2).
- recovery apparatus 62 which performs the said collection process (S4) are provided.
- fly ash FA in which oxide particles P1 and unburned carbon particles P2 are mixed is mixed with water L1 and hydrophobic solvent L2, and the mixed solution is stirred to form a first slurry.
- a mixing apparatus for executing this mixing step for example, a container equipped with a stirring blade for stirring the mixed solution, a line mixer, or a pump capable of stirring the mixed solution inside can be used.
- the mixer 51A in the example of FIG. 6 is a stirrer having a motor 511A and a stirring blade 512A.
- the mixer 51A is connected to a subsequent setter 52A via a pipe 80A.
- a fly ash FA that is a mixture to be separated, water L1, and a hydrophobic solvent L2 having a specific gravity greater than that of the water L1 are charged.
- the mixer 51A rotates the stirring blade 512A with the motor 511A, thereby mixing the fly ash FA, the water L1, and the hydrophobic solvent L2, and the first slurry (the oxide particles P1, the unburned carbon particles P2, and the water L1). And a mixed solution of the hydrophobic solvent L2) (mixing step).
- the settler 52A is an example of a separation device that performs a specific gravity separation step.
- the settler 52A by allowing the first slurry produced in the mixing step to stand, makes use of the specific gravity difference between the water L1 and the hydrophobic solvent L2, and the water phase ph1 mainly containing the oxide particles P1 and unburned Separated into a hydrophobic solvent phase ph2 mainly containing carbon particles P2.
- the settler 52A is an example of a specific gravity separation device that leaves a mixed liquid of a plurality of types of liquid and separates the liquid using a specific gravity difference, and is connected to the mixer 51A via a pipe 80A. . Further, the settler 52A is connected to the first recovery device 61 at the subsequent stage via a pipe 81A.
- the pipe 81A is provided with a pump 71A for sending out an aqueous phase ph1 (second slurry) containing the oxide particles P1. Further, the settler 52A is connected to the subsequent mixer 51B via a pipe 82A, and a pump 72A for sending the solvent phase ph2 (third slurry) containing unburned carbon particles P2 is connected to the pipe 82A. Is provided.
- the settler 52A uses the difference in specific gravity for the first slurry introduced from the mixer 51A through the pipe 80A, the upper phase aqueous phase ph1, and the lower phase hydrophobic solvent phase ph2 (hereinafter referred to as “solvent phase ph2”).
- solvent phase ph2 the lower phase hydrophobic solvent phase ph2
- the oxide particles P1 are moved to the aqueous phase ph1, and the unburned carbon particles P2 are moved to the solvent phase ph2. Thereby, the oxide particles P1 and the unburned carbon particles P2 are separated. Thereafter, the aqueous phase ph1 (second slurry) containing the oxide particles P1 is discharged from the upper part of the settler 52A to the first recovery device 61 through the pipe 81A.
- the solvent phase ph2 (third slurry) containing the unburned carbon particles P2 is discharged from the lower part of the settler 52A to the mixer 51B through the pipe 82A.
- This third slurry mainly includes unburned carbon particles P2 as solid content, but also includes oxide particles P1 that could not be separated.
- This water washing step (S22) includes a mixing step by a mixing device (mixer 51B) and a specific gravity separation step by a separation device (settler 52B).
- mixer 51B an apparatus having the same configuration as that of the mixer 51A described above can be used.
- settler 52B an apparatus having the same configuration as that of the above-described settler 52A can be used.
- the solvent phase ph2 (third slurry) supplied from the settler 52A is charged into the container of the mixer 51B.
- the mixer 51B rotates the stirring blade 512B by the motor 511B to mix the third slurry and the water L1, and the fourth slurry (unburned carbon particles P2, remaining oxide particles P1, water L1 and , A mixed solution of the hydrophobic solvent L2) (mixing step).
- the settler 52B is connected to the mixer 51B via a pipe 80B. Further, the settler 52B is connected to the first recovery device 61 at the subsequent stage via a pipe 81B.
- the pipe 81B is provided with a pump 71B for sending out an aqueous phase ph1 (fifth slurry) containing the oxide particles P1. Further, the settler 52B is connected to the second recovery device 62 at the subsequent stage via a pipe 82B.
- the pipe 82B is provided with a pump 72B for sending the solvent phase ph2 (sixth slurry) containing unburned carbon particles P2.
- the settler 52B is concentrated with the aqueous phase ph1 mainly containing the oxide particles P1 by using the difference in specific gravity between the water L1 and the hydrophobic solvent L2 by allowing the fourth slurry generated by the mixer 51B to stand. And separated into a solvent phase ph2 containing unburned carbon particles P2. Thereafter, the aqueous phase ph1 (fifth slurry) containing the oxide particles P1 is discharged from the upper part of the settler 52B to the first recovery device 61 through the pipe 81B. On the other hand, the solvent phase ph2 (sixth slurry) containing the unburned carbon particles P2 is discharged from the lower part of the settler 52B to the second recovery device 62 through the pipe 82B.
- separates the water L1 from the water phase ph1 containing the oxide particle P1 isolate
- the first recovery device 61 includes a centrifuge 611, a drying device 612, and a condenser 613.
- the centrifuge 611 is an example of a solid-liquid separator, and separates the solid suspended from the liquid and the liquid using centrifugal force.
- the centrifuge 611 is connected to the subsequent drying device 612 via a pipe 832 and connected to the previous mixers 51A and 51B via a pipe 831.
- the aqueous phase ph1 (second slurry, fifth slurry) containing the oxide particles P1 is introduced into the centrifuge 611 from the above settlers 52A, 52B.
- the centrifugal separator 611 uses centrifugal force to separate the slurry into a cake C1 containing oxide particles P1 and water L1 (solid-liquid separation step).
- the oxide particles P1 dehydrated by the centrifuge 611 are discharged to the drying device 612 through the pipe 832.
- the water L1 separated by the centrifugal separator 611 is returned to the mixers 51A and 51B through the pipe 831 and reused in the rough separation step (S21) and the water washing step (S22).
- a centrifugal separation process using a centrifuge 611 is used to separate the slurry into water L1 and oxide particles P1, but instead of this, a solidification such as a filter press or distillation or filtration is used.
- a liquid separation method may be used.
- the hydrophobic solvent L2 is volatile, it is preferable to use, for example, a distillation device, a centrifugal separator, or a filtration device as the solid-liquid separation device in order to reduce the leakage of the volatilized solvent gas.
- the drying device 612 heats the cake C1 including the oxide particles P1 introduced from the centrifuge 611 to evaporate the remaining moisture. Thereby, the oxide particles P1 are dried (drying step). The dried oxide particles P1 are discharged from the pipe 833 and collected.
- the condenser 613 condenses the water vapor sent from the drying device 612 through the pipe 834 and returns it to the liquid water L1 (condensing step). The liquid water L1 generated by the condenser 613 is returned to the mixer 51 through the pipe 835 and reused in the rough separation step (S21) and the water washing step (S22).
- Slurry) is separated into oxide particles P1 and water L1 by a centrifugal separator 611. Thereafter, the oxide particles P1 are dried by the drying device 612, and the dried oxide particles P1 are collected.
- the first recovery step (S3) is not limited to such an example, and for the aqueous phase ph1 (second and fifth slurries) containing the oxide particles P1 separated by the specific gravity separation step (S2), You may collect
- the water phase ph1 (second and fifth slurries) containing the oxide particles P1 separated in the specific gravity separation step (S2) is higher than the boiling point of the hydrophobic solvent L2. It is preferable to evaporate and remove the hydrophobic solvent L2 remaining in the aqueous phase ph1 by heating to a temperature of 2 ° C. or by reducing the pressure to a pressure at which the hydrophobic solvent L2 evaporates. Thereby, it can prevent that the hydrophobic solvent L2 is contained in the oxide particle P1 collect
- the hydrophobic solvent L2 is heated and evaporated together with the water L1 in the drying process by the drying device 612 shown in FIG. 6 to remain in the second and fifth slurries.
- the hydrophobic solvent L2 can be removed.
- the hydrophobic solvent L2 has volatility, it can be evaporated at room temperature, but since the specific gravity of the hydrophobic solvent L2 is larger than the specific gravity of the water L1, the hydrophobic solvent L2 should not be in direct contact with the gas phase. There are many. For this reason, it is preferable to perform stirring or aeration, and at this time, it is desirable to take measures so that the volatilized solvent L2 is not scattered.
- the boiling point of the hydrophobic solvent L2 is preferably 150 ° C. or lower under atmospheric pressure. Thereby, the hydrophobic solvent L2 can be evaporated and removed at low cost.
- the boiling point of the hydrophobic solvent L2 is preferably 95 ° C. or lower under atmospheric pressure. Thereby, since evaporation of the water L1 can be suppressed, the hydrophobic solvent L2 can be easily evaporated and removed with a small amount of heat.
- the boiling point of the hydrophobic solvent L2 is 40 degreeC or more under atmospheric pressure. Thereby, since the volatilization amount of the hydrophobic solvent L2 under normal temperature atmospheric pressure can be suppressed, collection
- the second recovery device 62 separates and removes the hydrophobic solvent L2 from the hydrophobic solvent phase ph2 (sixth slurry) containing the unburned carbon particles P2 separated in the specific gravity separation step (S2), and unburned.
- the carbon-containing powder P0 mainly composed of the carbon particles P2 is collected (S4).
- the second recovery device 62 includes a centrifuge 621, a drying device 622, and a condenser 623.
- the centrifuge 621 is connected to the subsequent drying device 622 via a pipe 842 and connected to the previous mixer 51A via a pipe 841.
- the hydrophobic solvent phase ph2 (sixth slurry) containing the unburned carbon particles P2 is introduced into the centrifuge 621 from the settler 52B.
- the centrifugal separator 621 uses centrifugal force to separate the sixth slurry into the cake C2 mainly composed of unburned carbon particles P2 and the hydrophobic solvent L2 (solid-liquid separation step (S41)). Unburned carbon particles P ⁇ b> 2 from which the hydrophobic solvent L ⁇ b> 2 has been separated by the centrifuge 621 are discharged to the drying device 622 through the pipe 842.
- the hydrophobic solvent L2 separated by the centrifugal separator 621 is returned to the mixer 51A through the pipe 841 and reused in the rough separation step (S21).
- a centrifugal separation process using a centrifuge 621 is used.
- a filter press or a distillation is used.
- a solid-liquid separation method such as filtration may be used.
- the drying device 622 heats the cake C2 containing the unburned carbon particles P2 introduced from the centrifuge 621 to volatilize the remaining hydrophobic solvent component. Thereby, the solid content mainly composed of the unburned carbon particles P2 is dried to obtain the carbon-containing powder P0 (drying step (S42)).
- the carbon-containing powder P0 mainly composed of the dried unburned carbon particles P2 is discharged from the pipe 843 and collected.
- the condenser 623 condenses the vapor of the hydrophobic solvent L2 sent from the drying device 622 through the pipe 844 and returns it to the liquid hydrophobic solvent L2 (condensing step).
- the liquid hydrophobic solvent L2 generated in the condenser 623 is returned to the mixer 51A through the pipe 845 and reused in the rough separation step (S21) (second recycling step).
- the solvent phase ph2 (sixth slurry) containing unburned carbon particles P2 separated in the specific gravity separation step (S2) in the second recovery step (S4). Is separated into a cake C2 containing unburned carbon particles P2 and a hydrophobic solvent L2 by a centrifugal separator 621. Thereafter, the cake C2 is dried by the drying device 622, and the carbon-containing powder P0 mainly composed of dry unburned carbon particles P2 is recovered.
- the configuration of the separation / recovery device 5 according to the present embodiment and the method for separating and collecting the carbon-containing powder P0 using the same have been described.
- the specific gravity separation step (S2), the first recovery step (S3), and the second recovery step (S4) are performed in parallel. Thereby, the separation efficiency and productivity of the oxide particles P1 and the unburned carbon particles P2 can be improved.
- the water L1 separated from the oxide particles P1 in the first recovery step (S3) is recovered and reused as the water L1 charged in the specific gravity separation step (S2), and the second recovery step (S4).
- the hydrophobic solvent L2 separated from the unburned carbon particles P2 and reuse it as the hydrophobic solvent L2 charged in the specific gravity separation step (S2).
- the hydrophobic solvent L2 can be repeatedly used in the specific gravity separation step (S2), and the chance that the unburned carbon particles P2 come into contact with the hydrophobic solvent L2 can be increased.
- the unburned carbon particles P2 in the fly ash FA are taken into the hydrophobic solvent phase ph2, and the oxide particles P1 are taken into the water phase. By incorporating it into ph1, the oxide particles P1 and the unburned carbon particles P2 can be separated with high efficiency.
- the separation and recovery method in the method for producing a carbon-containing powder according to the present embodiment has a separation rate and separation efficiency of oxide particles and unburned carbon particles as compared with the conventional flotation method described in Patent Document 1.
- the rough separation step (S21) according to the present embodiment can quickly separate the oxide particles P1 and the unburned carbon particles P2 in a short time, for example, about 1 second to 30 seconds.
- the content rate of the unburned carbon particle P2 mixed in the separated and recovered oxide particles P1 can be reduced to 3% by mass or less, and the oxide particles P1 having high purity can be recovered.
- the content rate of the oxide particles P1 mixed in the separated and recovered carbon-containing powder P0 can be reduced to less than 50% by mass, preferably 30% by mass or less. Therefore, since the content rate of the unburned carbon particles P2 contained in the carbon-containing powder P0 can be increased to 50% by mass or more, the carbon-containing powder P0 having a high carbon content and a low N / C ratio can be recovered.
- the oxide particles and unburned carbon particles may concentrate near the interface between the aqueous phase and the hydrophobic solvent phase.
- a mixture of trichlorethylene (specific gravity: 1.46) as a hydrophobic solvent and water (specific gravity: 1) is mixed with oxide particles (specific gravity: 2.4 to 2.6) as hydrophilic particles.
- a mixture for example, fly ash
- fly ash is added and left to stand for about 30 seconds or more.
- the oxide particles settle in the aqueous phase, while the unburned carbon particles (specific gravity: 1.3 to 1.5) float in the trichlorethylene phase.
- the oxide particles and the unburned carbon particles are concentrated, and the specific gravity gradually approaches.
- oxide particles and unburned carbon particles are mixed, so that the separation between them may be deteriorated. Therefore, in order to prevent the separation between the oxide particles and the unburned carbon particles from deteriorating, it is preferable to separate the aqueous phase and the hydrophobic solvent phase in a short time after standing, and further, the vicinity of the interface between the two phases. It may be preferable not to collect.
- the specific gravity of the oxide particles is larger, it is preferable to select a hydrophobic solvent having a larger specific gravity. Thereby, it can prevent that oxide particle settles from a water phase to a solvent phase.
- the specific gravity of the oxide particles is small, it is not necessary to dare to select a hydrophobic solvent having a small specific gravity, and the range of applicable specific gravity of the hydrophobic solvent can be expanded.
- the mass ratio of the oxide particles contained in the aqueous phase (that is, the slurry of water and oxide particles) is defined as the slurry concentration C S [mass%] of the aqueous phase.
- the slurry concentration CS is represented by the following formula (2).
- the value obtained by dividing the apparent density ⁇ S [g / cm 3 ] of the aqueous phase by the density ⁇ w [g / cm 3 ] of water at the same temperature and pressure is defined as the slurry specific gravity d S of the aqueous phase.
- the slurry specific gravity d S is represented by the following formula (3).
- the slurry specific gravity of the aqueous phase is less than the specific gravity of the hydrophobic solvent, the aqueous phase is unlikely to settle in the solvent phase, which is advantageous for suitably performing phase separation between the aqueous phase and the solvent phase. Therefore, it is preferable to adjust the mixing ratio of the mixture (fly ash) and water in the mixing step or to select a hydrophobic solvent having an appropriate specific gravity so that the settling is suppressed.
- the specific gravity of the hydrophobic solvent is more preferably more than 1.05.
- the specific gravity of the hydrophobic solvent is 1.05 or less
- the slurry concentration C S of the aqueous phase is set to a predetermined value or less. Need to be low. In this case, there exists a possibility that a separation apparatus may enlarge.
- the slurry concentration C S in the aqueous phase can be higher than the predetermined value, to increase the separation processing amount per unit time, a large There is no need to use a separator.
- water coating particles The apparent specific gravity of the oxide particles coated with the water coating (hereinafter also referred to as “water coating particles”) is smaller than the specific gravity of the oxide particles themselves. Therefore, it is preferable to select a hydrophobic solvent having a specific gravity larger than the apparent specific gravity of the water coating particles.
- grains can be floated from a solvent phase to an aqueous phase, and can be made to retain in an aqueous phase.
- the oxide particles can be quickly and efficiently separated from the hydrophobic solvent and the unburned carbon particles.
- the apparent specific gravity of the water-coated particles for example, 0.5 to 1 g of oxide particles are put into a mixed liquid consisting of 80 ml of water and 20 ml of a hydrophobic solvent in a measuring cylinder with a stopper. It is preferable to select a hydrophobic solvent in which most of the product particles do not settle in the solvent phase.
- the specific gravity of the hydrophobic solvent is preferably smaller than the specific gravity of the unburned carbon particles.
- the second recovery step (S4) when the unburned carbon particles P2 are separated from the solvent phase ph2 (third slurry) using the centrifuge 621, the liquid removal property is improved, and the unburned carbon particles are improved. P2 can be separated efficiently. Even when “the specific gravity of the unburned carbon particles P2 ⁇ the specific gravity of the hydrophobic solvent L2,” a centrifuge can be used although the liquid removal property is inferior, or a solid-liquid separation device of a filtration method or a distillation method is employed. You can also
- the particle diameter of the oxide particles is large enough that gravity exceeds the total of the buoyancy and interfacial tension acting on the oxide particles, or if the specific gravity of the oxide particles is large relative to the specific gravity of water, the particles It is thought that it moves from the phase to the solvent phase through the interface. In this case, the separation efficiency between the oxide particles and the unburned carbon particles decreases. From this point of view, it is preferable to remove oxide particles having a particle diameter or a specific gravity large enough to pass through the interface and move to the solvent phase before the separation treatment.
- the particle size of the oxide particles contained in the fly ash before the separation treatment may be 500 ⁇ m or less, and preferably 200 ⁇ m or less.
- the unburned carbon particles that floated in the hydrophobic solvent phase and reached the interface When the particle size of the unburned carbon particles is large, or the specific gravity of the unburned carbon particles is small relative to the specific gravity of the hydrophobic solvent, so that the buoyancy exceeds the sum of gravity and interfacial tension acting on the unburned carbon particles.
- the particles are considered to move from the solvent phase to the aqueous phase through the interface. From this point of view, it is preferable to remove the unburned carbon particles having a particle diameter or a specific gravity small enough to pass through the interface and move to the aqueous phase before the separation treatment.
- the particle size of the unburned carbon particles contained in the fly ash before the separation treatment may be 500 ⁇ m or less, and preferably 200 ⁇ m or less. These maximum particle sizes can be controlled by sieving with a sieve or classification with a cyclone.
- the manufacturing method according to the second embodiment further includes a pulverizing step of pulverizing unburned carbon particles in fly ash in order to increase the carbon content in the carbon-containing powder to be recovered.
- FIGS. 7 to 10 are process diagrams showing a separation and recovery method in the manufacturing method according to the second embodiment.
- the pulverization step (S5) is performed in the separation and recovery method according to the second embodiment.
- the pulverization step (S5) is added before the coarse separation step (S21) of the specific gravity separation step (S2).
- a pulverization step (S5) is added during the specific gravity separation step (S2), specifically, between the rough separation step (S21) and the water washing step (S22). ing.
- FIG. 7 First, the process example shown in FIG. 7 will be described.
- a pulverization process is performed on a mixed solution of fly ash FA, water L1, and hydrophobic solvent L2 (S5).
- S5 hydrophobic solvent L2
- the oxide particles P1 adhere to the surface of the unburned carbon particles P2 or the oxide particles P1 enter the pores P20 of the unburned carbon particles P2 as shown in FIG.
- the unburned carbon particles P2 are pulverized and refined.
- the oxide particles P1 in some of the pores P20 are released, the refined unburnt carbon particles P2 and the oxide particles P1 are separated or at least easily separated.
- the coarse separation step (S21) and the water washing step (S22) of the specific gravity separation step (S2) are performed.
- the pulverized unburned carbon particles P2 are easily separated from the oxide particles P1 and moved to the solvent phase ph2, and the oxide particles P1 are also separated from the unburned carbon particles P2 and moved to the water phase ph1. It becomes easy. Therefore, in the specific gravity separation step (S2), the oxide particles P1 and the unburned carbon particles P2 can be more preferably separated, so that the carbon content of the carbon-containing powder P0 recovered in the recovery step (S4) is 70 mass% or more. Can be increased.
- oxide powder can be obtained by solid-liquid separation and drying the aqueous phase ph1 containing the oxide particles P1 separated in the rough separation step (S21). Since the pulverization process is performed in the pulverization step (S5), the unburned carbon particles P2 associated with the oxide particles P1 are reduced compared to the fly ash FA before the process, and the carbon in the solid matter obtained from the aqueous phase ph1. The content is greatly reduced. The carbon content is large even when compared with the carbon content in the solid recovered from the aqueous phase ph1 containing the oxide particles P1 separated in the rough separation step (S21) of FIG. descend.
- FIG. 8 first, a pulverization process is performed on the mixed solution of fly ash FA and water L1 (S5). Thereby, similarly to the example of FIG. 7, the unburned carbon particles P2 are pulverized and refined, and the unburned carbon particles P2 and the oxide particles P1 are easily separated.
- the coarse separation step (S21) of the specific gravity separation step (S2) the hydrophobic solvent L2 is added to and mixed with the pulverized mixed solution, and the mixed solution is separated by specific gravity, and then the water washing step (S22) is performed. .
- a pulverization process is performed on the mixed solution of fly ash FA and the hydrophobic solvent L2 (S5).
- the unburned carbon particles P2 are pulverized and refined, and the unburned carbon particles P2 and the oxide particles P1 are easily separated.
- the coarse separation step (S21) of the specific gravity separation step (S2) water L1 is added to the pulverized mixed solution and mixed, and this mixed solution is separated by specific gravity, followed by the water washing step (S22).
- the mixed liquid obtained by adding either water L1 or hydrophobic solvent L2 to fly ash FA was pulverized.
- the specific gravity separation step (S2) the other of the water L1 or the hydrophobic solvent L2 is added to and mixed with the pulverized mixed solution, and then the specific gravity is separated.
- the oxide particles P1 and the unburned carbon particles P2 can be more suitably separated in the specific gravity separation step (S2), the carbon content in the carbon-containing powder P0 recovered in the recovery step (S4) is reduced. It can be increased to 70% by mass or more.
- oxide powder can be obtained by solid-liquid separation and drying the aqueous phase ph1 containing the oxide particles P1 separated in the rough separation step (S21). Since the pulverization process is performed in the pulverization step (S5), the unburned carbon particles P2 associated with the oxide particles P1 are reduced compared to the fly ash FA before the process, and the carbon in the solid matter obtained from the aqueous phase ph1. The content is greatly reduced. The carbon content is large even when compared with the carbon content in the solid recovered from the aqueous phase ph1 containing the oxide particles P1 separated in the rough separation step (S21) of FIG. descend.
- the process example of FIG. 10 will be described.
- the mixed liquid contains an aqueous phase ph1 mainly containing oxide particles P1 and a hydrophobic solvent phase ph2 mainly containing unburned carbon particles P2. Separated. Thereafter, the separated hydrophobic solvent phase ph2 is recovered, and in the pulverization step (S5), only the hydrophobic solvent phase ph2 is pulverized, and the aqueous phase ph1 is not pulverized.
- the unburned carbon particles P2 contained in the hydrophobic solvent phase ph2 are pulverized and refined, and are easily separated from the remaining oxide particles P1. Accordingly, in the subsequent water washing step (S22), the oxide particles P1 and the unburned carbon particles P2 can be more preferably separated, so that the carbon content in the carbon-containing powder P0 recovered in the recovery step (S4) is 70. It can be increased to more than mass%.
- the unburned carbon particles P2 in the solvent phase ph2 separated and recovered in the coarse separation step (S21) are crushed in the subsequent pulverization step (S5).
- the oxide particles P1 in the aqueous phase ph1 separated and recovered in the step (S21) are not pulverized.
- the pulverization process can be executed specifically for the unburned carbon particles P2, the pulverization efficiency of the unburned carbon particles P2 can be improved.
- both the unburned carbon particles P2 and the oxide particles P1 are pulverized.
- the pulverization process of the unburned carbon particles P2 and the oxide particles P1 is unified. It is a useful method because it can.
- a specific example of the pulverization method in the pulverization step (S5) will be described.
- a pulverization method in the pulverization step (S5) for example, a pulverization process using ultrasonic waves, a pulverization process using a high-speed shear mixer, a pulverization process using a ball mill or a bead mill can be used.
- a pulverization process using a high-speed shear mixer a pulverization process using a ball mill or a bead mill can be used.
- spherical beads are filled in a cylindrical container, and the stirring member is rotated while supplying a mixture (for example, fly ash) as an object to be pulverized.
- the bead diameter (hereinafter referred to as bead diameter) used in the grinding process by the bead mill is preferably 1 mm or less.
- the substantially spherical oxide particles are solid and hard and not easily crushed, but the unburned carbon particles are brittle and easily crushed.
- the diameter of the substantially spherical oxide particles is almost 100 ⁇ m or less, and the 50% particle diameter of the oxide particles is 1 to 20 ⁇ m.
- the harder oxide particles In order to pulverize unburned carbon particles having a smaller particle size between larger spherical oxide particles as the bead size is larger, the harder oxide particles must be pulverized. The possibility of collision of the fuel carbon particles is reduced.
- the bead diameter is preferably 1 mm or less.
- the density of the beads is preferably 3.5 g / cm 3 or more.
- the density of the beads is 3.5 g / cm 3 or more, the destructive force when the beads collide with the unburned carbon particles increases, so the time taken to pulverize the unburned carbon particles can be shortened, and the pulverization process Can be made more efficient.
- the material of the beads is preferably made of ceramic, metal or the like.
- the separation and recovery method according to the third embodiment employs a countercurrent multi-stage continuous process in which a combination of a mixing step by a mixing device (mixer) and a specific gravity separation step by a separation device (settler) is repeated in multiple stages.
- a multistage continuous process is employed in the coarse separation step (S21)
- the aqueous phase containing oxide particles and the solvent phase containing unburned carbon particles are separated in the multistage coarse separation step (S21).
- the separation efficiency of oxide particles and unburned carbon particles is further improved, and the oxide particles and unburned carbon contained in the recovered solid matter.
- the content of particles can be increased. The same applies when a multi-stage continuous process is employed in the water washing step (S22).
- both the rough separation step (S21) and the water washing step (S22) are repeated in multiple stages.
- the coarse separation step (S21) is repeated N steps (N is an integer of 2 or more), and the water washing step (S22) is repeated M steps (M is an integer of 2 or more).
- the oxide particles P1 separated in the specific gravity separation step of the n-th stage when N is an integer of 3 or more, the oxide particles P1 separated in the specific gravity separation step of the n-th stage (n is an integer of 1 or more and N-2 or less) and The aqueous phase ph1 containing the remaining unburned carbon particles P2 and the solvent phase ph2 containing the unburned carbon particles P2 separated in the n + 2 stage specific gravity separation step and the remaining oxide particles P1 are mixed in the n + 1 stage. It is mixed and slurried in the process.
- the water phase ph1 mainly containing oxide particles P1 and the solvent phase ph2 mainly containing unburned carbon particles P2 are separated.
- an aqueous phase ph1 having a higher content of oxide particles P1 is obtained from the first stage to the N stage, while from the N stage.
- the solvent phase ph2 having a higher content of unburned carbon particles P2 is obtained as it goes to the first stage.
- the water washing step (S22) is the same as the rough separation step (S21).
- the solvent phase ph2 having a higher content of unburned carbon particles P2 is obtained from the first stage to the M stage, while water having a higher content of oxide particles P1 is obtained from the M stage to the first stage. Phase ph1 is obtained.
- Hydrophobic solvent L2 is charged in the N-th mixing step.
- the oxide particles P1 and the water L1 are separated and recovered from the aqueous phase ph1 having a high content of the oxide particles P1.
- the recovered water L1 is returned to the M-th mixing step and reused.
- water L1 is charged in the M-th mixing step.
- the second recovery step (S4) in the latter stage of the Mth stage, the unburned carbon particles P2 and the hydrophobic solvent L2 are separated and recovered from the solvent phase ph2 having a high content of the unburned carbon particles P2.
- the recovered hydrophobic solvent L2 is returned to the N-th mixing step and reused.
- fly ash FA is introduced in the first stage mixing step, but fly ash FA may be introduced in the other stage mixing step.
- one of the rough separation step (S21) and the water washing step (S22) may be a single step, in other words, M or N may be 1.
- a grinding step (S5) may be added before or after the rough separation step (S21) or the water washing step (S22) at any stage.
- the carbon content of the carbon-containing powder according to the present embodiment is very high, at least 50% by mass, preferably 70% by mass or more. Accordingly, the combustion efficiency can be increased during the combustion of the carbon-containing powder. Further, the N / C ratio of the carbon-containing powder is 0.02 or less, very low, and the nitrogen content is low. Therefore, generation of nitrogen oxides (NOx) can be suppressed during combustion of the carbon-containing powder.
- NOx nitrogen oxides
- the carbon-containing powder according to the present embodiment should be effectively used as an alternative to low-nitrogen coal (ie, low nitrogen coal) used in sintering machines, combustion furnaces such as power plants, converters, etc. Can be very useful in industry.
- low-nitrogen coal ie, low nitrogen coal
- the carbon-containing powder according to the present embodiment contains a large amount of unburned carbon particles that are porous particles, and the specific surface area is 50 to 300 m 2 / g, which is the same as that of activated coke powder. It is several tens to hundred times larger than the surface area (0.5 to 10 m 2 / g). Therefore, the carbon-containing powder according to the present embodiment has SO 2 adsorption capacity and denitration capacity, and can be effectively used as an SO 2 adsorption material and denitration material. In particular, when the pulverization treatment is performed as in the second embodiment, the specific surface area of the carbon-containing powder becomes larger, and therefore, it can be effectively used as a high-quality SO 2 adsorbent or denitration material.
- the carbon-containing powder and other powders are kneaded to increase the bulk specific gravity of the carbon-containing powder.
- Carbon-containing powder is a porous material, its bulk specific gravity is small, and its particle diameter is small, so it is a very difficult particle to handle by itself. Therefore, it is preferable to increase the bulk specific gravity (for example, 1 g / cm 3 or more) by mixing the carbon-containing powder with another powder material having a large bulk specific gravity. Thereby, generation
- Example 1 First, the test of Example 1 will be described with reference to Table 3. Table 3 shows the test conditions and results of Example 1.
- the slurry concentration C S [mass%] in the aqueous phase becomes the concentration shown in Table 3.
- the mixture (P1 + P2) was charged. Fly ash was used as a mixture (P1 + P2).
- the mixed solution in the graduated cylinder was vigorously mixed by hand for 10 seconds and then allowed to stand for 10 seconds. Thereafter, a sample was immediately taken from the aqueous phase portion, the solid in the aqueous phase was recovered, and the content of the recovered solid was measured.
- the unburned carbon particles separation rate K A represented by the following formula (4).
- the oxide particles recovery K B is calculated by the following equation (5).
- the content C C of unburned carbon particles in fly ash used as a mixture is separated target in Comparative Example 1 and Examples 1-1 ⁇ 1-9 (P1 + P2) 1.
- the volume-based 50% particle size of the fly ash was 19 ⁇ m.
- Content C C of unburned carbon particles in fly ash Examples 1-10 to 1-13 was 5.3 wt%, the 50% particle diameter on a volume basis of the fly ash was 21 [mu] m.
- the content C B of unburned carbon particles in the solid recovered from the aqueous phase was 1.2% by mass in Example 1-1 where the specific gravity of the silicone oil as the hydrophobic liquid L2 was 1.07. It was. On the other hand, in Comparative Example 1 the specific gravity of the silicone oil is 1.03, and the content C B was 1.9 wt%. Therefore, it can be seen that the specific gravity separation rate can be improved by setting the specific gravity of the hydrophobic liquid L2 to more than 1.05. That is, in Comparative Example 1, since the specific gravity of the silicone oil is 1.05 or less, the specific gravity of the aqueous phase is close to the specific gravity of the hydrophobic liquid phase, and the phase separation rate is very slow.
- Comparative Example 1 the mixture was allowed to stand for 1 minute after the above mixing, but the phase separation hardly proceeded. Therefore, taken approximately 20ml of the graduated cylinder top, the solid was collected, was measured content C B of unburned carbon particles in the recovered product was 1.9% by mass%. In other words, there was little change from content C C of unburned carbon particles in fly ash was charged.
- Example 2 In Example 2, trichloroethylene was used as a hydrophobic solvent, and carbon-containing powder was recovered from fly ash (hereinafter simply referred to as FA) based on the separation and recovery method shown in FIG.
- FA fly ash
- the aqueous phase in which the oxide was concentrated was recovered, and after filtration, the solid was dried and recovered.
- 250 ml of water was added to the recovered trichlorethylene phase, and the sealed container (separation funnel) was vigorously shaken by hand for 30 seconds to mix the trichlorethylene phase and water. Thereafter, the sealed container (separation funnel) was allowed to stand for 10 seconds, and the trichlorethylene phase in which unburned carbon was concentrated was collected again (water washing step S22). At this time, the sample near the interface between the trichlorethylene phase and the aqueous phase was not recovered and discarded.
- This water washing step S22 was repeated three times to recover the trichlorethylene phase in which unburned carbon was concentrated. After filtering the collected trichlorethylene phase (solid-liquid separation step S41), water and trichlorethylene were volatilized by drying (drying step S42) to obtain a carbon-containing powder.
- the carbon content of the carbon-containing powder of Example 2 is 57% by mass, and the N / C ratio (mass ratio), which is the ratio between the nitrogen content and the carbon content in the carbon-containing powder, is 0. .0072.
- the total SiO 2 component and Al 2 O 3 component in the oxide particles in the carbon-containing powder was not less than 75 mass%.
- recovered from the water phase was 2.8 mass%, and it was confirmed that it has fallen compared with the carbon content rate in FA before a process.
- Comparative Example 2 carbon-containing powder was recovered from FA based on the flotation method described in Example 1 of Patent Document 1.
- the carbon content of the carbon concentrate of Comparative Example 2 was 34% by mass, and the N / C ratio was 0.0095.
- Example 3 In Example 3, the carbon concentrate obtained in Comparative Example 2 (carbon content: 34% by mass) was treated in the same manner as in Example 2 to obtain a carbon-containing powder. As a result, the carbon content of the carbon-containing powder of Example 3 was 56% by mass, and the N / C ratio was 0.0074. The total SiO 2 component and Al 2 O 3 component in the oxide particles in the carbon-containing powder was not less than 75 mass%.
- Example 4 In Example 4, 1-bromopropane was used as a hydrophobic solvent, and carbon-containing powder was recovered from FA based on the separation and recovery method shown in FIG.
- the mixed solution was transferred to a sealed container (separation funnel), and the sealed container (separation funnel) was vigorously shaken by hand for 30 seconds to thoroughly mix FA, water, and 1-bromopropane.
- the sealed container (separation funnel) was allowed to stand for 10 seconds, the 1-bromopropane phase in which unburned carbon was concentrated was recovered, and the aqueous phase was discarded (coarse separation step S21). Further, after discarding the sample near the interface between the 1-bromopropane phase and the aqueous phase, the aqueous phase in which the oxide was concentrated was recovered, and after filtration, the solid was dried and recovered.
- the recovered 1-bromopropane phase was placed in a sealed container (separation funnel), 250 ml of water was added, and the sealed container (separation funnel) was shaken vigorously by hand for 30 seconds to mix the 1-bromopropane phase and water. Thereafter, the sealed container (separation funnel) was allowed to stand for 10 seconds, and the 1-bromopropane phase in which unburned carbon was concentrated was collected again (water washing step S22). At this time, the sample near the interface between the 1-bromopropane phase and the aqueous phase was not recovered and discarded. This water washing step S22 was repeated three times to recover the 1-bromopropane phase in which unburned carbon was concentrated. After filtering the collected 1-bromopropane phase (solid-liquid separation step S41), water and 1-bromopropane were volatilized by drying (drying step S42) to obtain a carbon-containing powder.
- the carbon content of the carbon-containing powder of Example 4 was 82% by mass, and the N / C ratio was 0.0061.
- the total SiO 2 component and Al 2 O 3 component in the oxide particles in the carbon-containing powder was not less than 75 mass%.
- the carbon content in the solid recovered from the aqueous phase is 1.2% by mass, which is lower than the carbon content in the FA before the treatment, and from the aqueous phase obtained in Example 2. It was confirmed that the carbon content in the recovered solid was also reduced.
- Example 5 In Example 5, trichloroethylene was used as the hydrophobic solvent, and carbon-containing powder was recovered from FA based on the separation and recovery method shown in FIG.
- the mixed solution in the container was pulverized by a high-speed shear mixer (homogenizer) for 3 minutes (pulverization step S5). After the pulverization treatment, the mixed solution is transferred to a sealed container (separation funnel), 250 ml of trichlorethylene (specific gravity: 1.46) is added, and the sealed container (separation funnel) is shaken vigorously by hand for 30 seconds. Trichlorethylene was mixed well.
- the sealed container (separation funnel) was allowed to stand for 10 seconds, and the trichlorethylene phase in which the unburned carbon was concentrated was collected and put into another sealed container (separation funnel) (coarse separation step S21). Further, after discarding the sample near the interface between the trichlorethylene phase and the aqueous phase, the aqueous phase in which the oxide was concentrated was recovered, and after filtration, the solid was dried and recovered.
- the carbon content of the carbon-containing powder of Example 5 was 87% by mass, and the N / C ratio was 0.011.
- the total SiO 2 component and Al 2 O 3 component in the oxide particles in the carbon-containing powder was not less than 75 mass%.
- the carbon content in the solid recovered from the aqueous phase is 1.4% by mass, which is lower than the carbon content in the FA before the treatment, and from the aqueous phase obtained in Example 2. It was confirmed that the carbon content in the recovered solid was also reduced.
- Example 5-1 In Example 5-1, trichloroethylene was used as a hydrophobic solvent, and carbon-containing powder was recovered from FA based on the separation and recovery method shown in FIG.
- the upper aqueous phase containing the pulverized FA in the container is collected, transferred to another sealed container (separation funnel), 250 ml of trichlorethylene (specific gravity: 1.46) is added, and the sealed container (separation funnel) is removed. Shake vigorously by hand for 30 seconds to mix FA, water and trichlorethylene well. After mixing, the sealed container (separation funnel) was allowed to stand for 10 seconds, and the trichlorethylene phase in which the unburned carbon was concentrated was collected and put into another sealed container (separation funnel) (coarse separation step S21). At this time, the sample near the interface between the trichlorethylene phase and the aqueous phase was discarded.
- Example 6 In Example 6, trichloroethylene was used as a hydrophobic solvent, and carbon-containing powder was recovered from FA based on the separation and recovery method shown in FIG.
- the trichlorethylene phase containing the pulverized FA in the upper part of the sealed container is collected, transferred to another sealed container (separation funnel), 250 ml of water is added, and the sealed container (separation funnel) is shaken vigorously by hand for 30 seconds. Then, FA, water, and trichlorethylene were mixed well. After mixing, the sealed container (separation funnel) was allowed to stand for 10 seconds, and the trichlorethylene phase in which the unburned carbon was concentrated was collected and put into another sealed container (separation funnel) (coarse separation step S21).
- the aqueous phase in which the oxide was concentrated was recovered, and after filtration, the solid was dried and recovered.
- 100 ml of water was added to the recovered trichlorethylene phase, and the sealed container (separation funnel) was shaken vigorously by hand for 30 seconds to mix the trichlorethylene phase and water. Thereafter, the sealed container (separation funnel) was allowed to stand for 10 seconds, and the trichlorethylene phase in which unburned carbon was concentrated was collected again (water washing step S22). At this time, the sample near the interface between the trichlorethylene phase and the aqueous phase was not recovered and discarded.
- This water washing step S22 was repeated three times to recover the trichlorethylene phase in which unburned carbon was concentrated. After filtering the collected trichlorethylene phase (solid-liquid separation step S41), water and trichlorethylene were volatilized by drying (drying step S42) to obtain a carbon-containing powder.
- the carbon content of the carbon-containing powder of Example 6 was 85% by mass, and the N / C ratio was 0.0068.
- the total SiO 2 component and Al 2 O 3 component in the oxide particles in the carbon-containing powder was not less than 75 mass%.
- the carbon content in the solid recovered from the aqueous phase is 1.0% by mass, which is lower than the carbon content in the FA before the treatment, and from the aqueous phase obtained in Example 2. It was confirmed that the carbon content in the recovered solid was also reduced.
- Example 7 In Example 7, trichloroethylene was used as a hydrophobic solvent, and carbon-containing powder was recovered from FA based on the separation and recovery method shown in FIG.
- the carbon content of the carbon-containing powder of Example 7 was 86% by mass, and the N / C ratio was 0.0081.
- the total SiO 2 component and Al 2 O 3 component in the oxide particles in the carbon-containing powder was not less than 75 mass%.
- Table 4 shows the results of Examples 2 to 5, 6, 7 and Comparative Example 2 described above.
- the carbon content of the carbon-containing powders of Examples 2 to 7 of the present invention is 56 to 87% by mass, which satisfies the reference of 50% by mass or more.
- the carbon content is 82% by mass or more, which satisfies the higher standard of 70% by mass or more.
- the carbon content of the carbon-containing powder of Comparative Example 2 is as low as 34% by mass, which is less than 50% by mass as a reference.
- the unburned carbon particles are suitably separated from the FA by the separation and recovery method in the production method according to this embodiment, and a carbon-containing powder having a carbon content of at least 50% by mass or more is preferably obtained. Can be said.
- Example 8 the carbon-containing powder (Table 5) obtained from FA (carbon content: 11.8% by mass) in the same manner as in Example 2 was used for coke used in the sintering process of the sintering machine. Kneaded and used as a sintering raw material. And the carbon containing powder in a sintering process was evaluated by the pan test. For comparison, a test using only coke, which is a normal operation, was performed in the same manner.
- the sintered sample was put into a pan testing apparatus up to a height of 600 mm, and the surface layer was ignited for 90 seconds in an ignition furnace while firing at 1500 mmAq with a blower, followed by firing.
- the results of this sinter production test were as shown in Table 6 below.
- the average NOx concentration in the exhaust gas generated during the production of sintered ore was reduced. This is thought to be because the carbon-containing powder was low in nitrogen at an N / C ratio compared to coke, and thus the amount of generated NOx could be reduced.
- Example 9 In Example 9, the carbon-containing powder (Table 6) obtained by the same method as in Example 2 and another powder (scale) were mixed in advance to increase the bulk density. Then, the mixed material was kneaded into coke used in the sintering process of the sintering machine and used as a sintering raw material. And the carbon containing powder in a sintering process was evaluated by the pan test. For comparison, a test using only coke, which is a normal operation, was performed in the same manner.
- the sintered sample was put into a pan testing apparatus up to a height of 600 mm, and the surface layer was ignited for 90 seconds in an ignition furnace while firing at 1500 mmAq with a blower, followed by firing.
- the results of this sinter preparation test were as shown in Table 7 below. As shown in Table 7, even when the scale and carbon-containing powder were previously kneaded, massive ( ⁇ 5 mm-sieving) sintered ore was obtained with a yield equivalent to that of coke, which is a normal operation. Therefore, it was found that there is no problem in using the carbon-containing powder as a sintering raw material. On the other hand, like Example 8, the NOx average concentration in the exhaust gas generated during the production of sintered ore was reduced.
- Example 10 In Example 10, the specific surface area, SO 2 adsorption capacity, and denitration capacity of the carbon-containing powder samples obtained in Example 2 and Example 5 were measured. The results are shown in Table 8.
- the specific surface area of the carbon-containing powder of Example 5 was increased by a factor of about 2 due to pulverization, but the SO 2 adsorption capacity and denitration capacity were further increased. This is presumably because the substantially spherical oxide that had entered the fine pores was removed by pulverization, and most of the fine pores acted as SO 2 adsorption ability and denitration ability.
- Example 11 carbon-containing powder was recovered from FA by the countercurrent multistage continuous process shown in FIG.
- the capacities of the mixers 51A and 51B were each 0.3L.
- An upflow separator (diameter: 40 mm, height: 300 mm) was used as the settlers 52A and 52B.
- a bromine-based organic solvent phase was formed at the lower part of the settler 52A and the settler 52B, an aqueous phase was formed at the upper part, and a thin film of a bromine-based organic solvent phase was formed between the aqueous phase and air.
- the aqueous phase was continuously withdrawn at a rate of about 1 L / min from the surface layer portion of the aqueous phase, and a sample for analysis of the aqueous phase was obtained.
- the bromine-based organic solvent phase was continuously withdrawn from the bottom of the bromine-based organic solvent phase at a rate of about 3 cm at a rate of 1 L / min to obtain a solvent phase analysis sample.
- the unburned carbon particles separation rate K A is 82 mass%
- hydrophilic particles recovery K B was 91% by mass.
- the content C B of unburned carbon particles in the solid recovered from the aqueous phase in the first recovery step (S3) is: It was 2.8% by mass.
- the content C A of unburned carbon particles solids in the recovered bromine-based organic solvent phase in the second recovery step (S4) was 58 wt%.
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Abstract
[Problem] To provide a novel and improved carbon-containing powder. [Solution] A carbon-containing powder containing carbon particles P2 and oxide particles P1, wherein the content of a carbon component in the carbon-containing powder is 50 to 95% by mass inclusive, the oxide particles P1 are particles made from a compound containing a SiO2 component and/or a Al2O3 component, the total content of the SiO2 component and the Al2O3 component in the oxide particles P1 is 75% by mass or more, the carbon particles P2 are porous particles each having multiple pores P20 formed therein, at least a portion of the oxide particles P1 is present in the pores P20 in the carbon particles P2.
Description
本発明は、炭素含有粉に関する。
The present invention relates to a carbon-containing powder.
石炭焚き火力発電所等における発電時に発生するフライアッシュの多くは、コンクリート用原料、建材原料、セメント用原料等にリサイクルされている。フライアッシュは、Al2O3、SiO2等の金属酸化物からなる灰分と、燃え残った炭素成分である未燃カーボンを含んでいる。このため、建材原料、コンクリート用原料(混和剤)等として利用するには、フライアッシュ中に含まれる未燃カーボンを分離し、未燃カーボン濃度を低下させることが好ましい。
Most fly ash generated during power generation at coal-fired thermal power plants is recycled into concrete raw materials, building material raw materials, cement raw materials, and the like. The fly ash contains ash composed of a metal oxide such as Al 2 O 3 or SiO 2 and unburned carbon that is a carbon component that remains unburned. For this reason, in order to use it as a building material raw material, a concrete raw material (admixture), etc., it is preferable to separate unburned carbon contained in fly ash and reduce the unburned carbon concentration.
フライアッシュ中の未燃カーボンを分離する方法として、例えば、静電分離方法や浮選方法が知られている。静電分離方法は、乾式状態で、平行平板の電極内にフライアッシュを投入することにより、帯電させた未燃カーボンを正電極側に引き寄せて分離する方法である。また、浮選方法は、フライアッシュのスラリー内で気泡剤を用いて発生させたマイクロエアーに対し、灯油等の捕集剤を介して未燃カーボン粒子を付着させることで、未燃カーボン粒子を浮上させて分離する方法である。
For example, an electrostatic separation method or a flotation method is known as a method for separating unburned carbon in fly ash. The electrostatic separation method is a method in which fly ash is introduced into parallel plate electrodes in a dry state to attract and separate charged unburned carbon toward the positive electrode side. In addition, the flotation method is to attach unburned carbon particles to micro air generated using a foaming agent in a slurry of fly ash through a scavenger such as kerosene. It is a method of floating and separating.
例えば、特許文献1には、フライアッシュ中の未燃カーボンを浮選により除去する方法が開示されている。この特許文献1の浮選方法では、まず、水を添加してスラリー化したフライアッシュを撹拌することにより、未燃カーボン粒子の表面に活性エネルギーを生じさせて、未燃カーボン粒子を親油化(疎水化)する。次いで、親油化した未燃カーボンを含むスラリーに、灯油、軽油等の捕集剤及び起泡剤を添加して、捕集剤を未燃カーボンに付着させるともに、発生した気泡に未燃カーボンを付着させて浮選する。かかる浮選方法により、疎水性粒子である未燃カーボン(比重:1.3~1.5)と、親水性粒子である金属酸化物(比重:2.4~2.6)との混合物であるフライアッシュから、未燃カーボンが分離される。
For example, Patent Document 1 discloses a method for removing unburned carbon in fly ash by flotation. In the flotation method of Patent Document 1, first, the fly ash that has been slurried by adding water is stirred to generate active energy on the surface of the unburned carbon particles, thereby making the unburned carbon particles oleophilic. (Hydrophobic). Next, a trapping agent such as kerosene and light oil and a foaming agent are added to the slurry containing the oleophilic unburnt carbon, and the trapping agent is attached to the unburned carbon and unburned carbon is generated in the generated bubbles. Flotation with the attached. By such a flotation method, a mixture of unburned carbon (specific gravity: 1.3 to 1.5) as hydrophobic particles and metal oxide (specific gravity: 2.4 to 2.6) as hydrophilic particles is used. Unburnt carbon is separated from some fly ash.
ところで、フライアッシュをリサイクルするに際し、上記のようにAl2O3、SiO2等の金属酸化物のみならず、未燃カーボンについても有効利用することが望ましい。
By the way, when recycling fly ash, it is desirable to effectively use not only unburned carbon but also metal oxides such as Al 2 O 3 and SiO 2 as described above.
しかしながら、上記特許文献1に記載のようにフライアッシュに含まれる未燃カーボンを気泡に付着させて浮上させる浮選方法では、分離速度が遅く、分離効率が悪いという問題があった。このため、分離した未燃カーボン中に金属酸化物の微細粒子が多く残存してしまうので、未燃カーボンのみを高い炭素含有率で分離・回収することが困難であった。さらに、SiO2、Al2O3等の金属酸化物の微細粒子は、乾燥状態において、ファンデルワールス力や静電気力などの引力で他の粒子と凝集しやすいため、未燃カーボン粒子に対しても付着してしまう。このため、フライアッシュ中に含まれる未燃カーボン粒子と金属酸化物の微細粒子とを適切に分離することは、より一層困難であった。
However, the flotation method in which the unburned carbon contained in the fly ash is floated by adhering to the bubbles as described in Patent Document 1 has a problem that the separation speed is slow and the separation efficiency is poor. For this reason, since many fine particles of metal oxide remain in the separated unburned carbon, it is difficult to separate and recover only unburned carbon with a high carbon content. Furthermore, fine particles of metal oxides such as SiO 2 and Al 2 O 3 tend to agglomerate with other particles due to attractive forces such as van der Waals force and electrostatic force in the dry state. Will also adhere. For this reason, it was much more difficult to properly separate the unburned carbon particles and the fine metal oxide particles contained in the fly ash.
これらの理由から、従来の分離方法では、フライアッシュ中に含まれる未燃カーボンを、高い炭素含有率で分離することが困難であった。このため、従来では、フライアッシュから分離・回収した未燃カーボン単独の特性を解明できておらず、未燃カーボンの有効利用の阻害要因となっていた。従って、従来では、フライアッシュ等の石炭灰から炭素含有率の高い未燃カーボン等の炭素含有粉を分離して、その特性を解明し、当該炭素含有粉を有効利用することが希求されていた。
For these reasons, it has been difficult to separate unburned carbon contained in fly ash with a high carbon content by the conventional separation method. For this reason, conventionally, the characteristics of the unburned carbon alone separated and recovered from fly ash have not been elucidated, which has been an obstacle to the effective use of unburned carbon. Therefore, conventionally, there has been a demand for separating carbon-containing powder such as unburned carbon having a high carbon content from coal ash such as fly ash, elucidating its characteristics, and effectively utilizing the carbon-containing powder. .
そこで、本発明は、上記問題に鑑みてなされたものであり、本発明の目的は、新規かつ改良された、炭素含有粉と、分離方法及び炭素含有粉の利用方法を提供することにある。
Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to provide a new and improved carbon-containing powder, a separation method, and a method of using the carbon-containing powder.
上記課題を解決するために、本発明のある観点によれば、
炭素粒子と酸化物粒子を含有する炭素含有粉であって、
前記炭素含有粉中の炭素成分の含有率が、50質量%以上、95質量%以下であり、
前記酸化物粒子は、SiO2成分又はAl2O3成分のうちいずれか一方若しくは双方を含む化合物からなる粒子であり、前記酸化物粒子中の前記SiO2成分と前記Al2O3成分の合計の含有率が、75質量%以上であり、
前記炭素粒子は、複数の細孔が形成された多孔質粒子であり、
前記酸化物粒子の少なくとも一部は、前記炭素粒子の細孔中に存在する、炭素含有粉が提供される。 In order to solve the above problems, according to one aspect of the present invention,
A carbon-containing powder containing carbon particles and oxide particles,
The carbon component content in the carbon-containing powder is 50% by mass or more and 95% by mass or less,
The oxide particles are particles composed of a compound containing one or both one of the SiO 2 component or Al 2 O 3 component, the total of the said SiO 2 component Al 2 O 3 component of the oxide particles The content of is 75% by mass or more,
The carbon particles are porous particles in which a plurality of pores are formed,
A carbon-containing powder is provided in which at least part of the oxide particles are present in the pores of the carbon particles.
炭素粒子と酸化物粒子を含有する炭素含有粉であって、
前記炭素含有粉中の炭素成分の含有率が、50質量%以上、95質量%以下であり、
前記酸化物粒子は、SiO2成分又はAl2O3成分のうちいずれか一方若しくは双方を含む化合物からなる粒子であり、前記酸化物粒子中の前記SiO2成分と前記Al2O3成分の合計の含有率が、75質量%以上であり、
前記炭素粒子は、複数の細孔が形成された多孔質粒子であり、
前記酸化物粒子の少なくとも一部は、前記炭素粒子の細孔中に存在する、炭素含有粉が提供される。 In order to solve the above problems, according to one aspect of the present invention,
A carbon-containing powder containing carbon particles and oxide particles,
The carbon component content in the carbon-containing powder is 50% by mass or more and 95% by mass or less,
The oxide particles are particles composed of a compound containing one or both one of the SiO 2 component or Al 2 O 3 component, the total of the said SiO 2 component Al 2 O 3 component of the oxide particles The content of is 75% by mass or more,
The carbon particles are porous particles in which a plurality of pores are formed,
A carbon-containing powder is provided in which at least part of the oxide particles are present in the pores of the carbon particles.
前記炭素含有粉中の前記炭素成分の含有率が、70質量%以上、95質量%以下であるようにしてもよい。
The content of the carbon component in the carbon-containing powder may be 70% by mass or more and 95% by mass or less.
前記炭素含有粉に含まれる窒素成分と前記炭素成分の質量比であるN/C比が、0超、0.02以下であるようにしてもよい。
The N / C ratio, which is the mass ratio between the nitrogen component contained in the carbon-containing powder and the carbon component, may be more than 0 and 0.02 or less.
前記酸化物粒子の粒子径が、体積基準の50%粒子径で、1~20μmであるようにしてもよい。
The particle diameter of the oxide particles may be 1 to 20 μm with a volume-based 50% particle diameter.
前記酸化物粒子の円形度の平均値が、0.9超、1以下であるようにしてもよい。
The average value of the circularity of the oxide particles may be more than 0.9 and 1 or less.
前記酸化物粒子中の前記SiO2成分の含有率が、50質量%以上、80質量%以下であり、
前記酸化物粒子中の前記Al2O3成分の含有率が、10質量%以上、30質量%以下であるようにしてもよい。 The content of the SiO 2 component in the oxide particles is 50% by mass or more and 80% by mass or less,
The content of the Al 2 O 3 component in the oxide particles, 10 mass% or more, may be is 30 mass% or less.
前記酸化物粒子中の前記Al2O3成分の含有率が、10質量%以上、30質量%以下であるようにしてもよい。 The content of the SiO 2 component in the oxide particles is 50% by mass or more and 80% by mass or less,
The content of the Al 2 O 3 component in the oxide particles, 10 mass% or more, may be is 30 mass% or less.
前記炭素含有粉の比表面積が、50~300m2/gであるようにしてもよい。
The carbon-containing powder may have a specific surface area of 50 to 300 m 2 / g.
また、上記課題を解決するために、本発明の別の観点によれば、
フライアッシュに由来し、炭素粒子と酸化物粒子とが混在する混合物から、炭素粒子と酸化物粒子とを分離する分離方法であって、
前記混合物と、水と、前記水より比重が大きい疎水性液体とを混合して混合液を生成する混合工程と、
前記混合液を静置し、前記炭素粒子を含む疎水性液体相と、前記酸化物粒子を含む水相とに分離させることにより、前記炭素粒子と前記酸化物粒子とを分離する比重分離工程と、を含む、分離方法が提供される。 In order to solve the above problem, according to another aspect of the present invention,
A separation method for separating carbon particles and oxide particles from a mixture of carbon particles and oxide particles derived from fly ash,
A mixing step of mixing the mixture, water, and a hydrophobic liquid having a specific gravity greater than that of the water to produce a mixture;
A specific gravity separation step of separating the carbon particles and the oxide particles by allowing the mixed liquid to stand and separating the mixture into a hydrophobic liquid phase containing the carbon particles and an aqueous phase containing the oxide particles; A separation method is provided.
フライアッシュに由来し、炭素粒子と酸化物粒子とが混在する混合物から、炭素粒子と酸化物粒子とを分離する分離方法であって、
前記混合物と、水と、前記水より比重が大きい疎水性液体とを混合して混合液を生成する混合工程と、
前記混合液を静置し、前記炭素粒子を含む疎水性液体相と、前記酸化物粒子を含む水相とに分離させることにより、前記炭素粒子と前記酸化物粒子とを分離する比重分離工程と、を含む、分離方法が提供される。 In order to solve the above problem, according to another aspect of the present invention,
A separation method for separating carbon particles and oxide particles from a mixture of carbon particles and oxide particles derived from fly ash,
A mixing step of mixing the mixture, water, and a hydrophobic liquid having a specific gravity greater than that of the water to produce a mixture;
A specific gravity separation step of separating the carbon particles and the oxide particles by allowing the mixed liquid to stand and separating the mixture into a hydrophobic liquid phase containing the carbon particles and an aqueous phase containing the oxide particles; A separation method is provided.
前記比重分離工程で分離された前記水相から、前記水を分離することにより、前記酸化物粒子を回収する第1回収工程を更に含むようにしてもよい。
A first recovery step of recovering the oxide particles by separating the water from the aqueous phase separated in the specific gravity separation step may be further included.
前記比重分離工程で分離された前記疎水性液体相から、前記疎水性液体を分離することにより、炭素含有粉を回収する第2回収工程を更に含み、
前記炭素含有粉は、前記炭素粒子と前記酸化物粒子を含有し、
前記炭素含有粉中の炭素成分の含有率が、50質量%以上、95質量%以下であり、
前記酸化物粒子は、SiO2成分又はAl2O3成分のうちいずれか一方若しくは双方を含む化合物からなる粒子であり、前記酸化物粒子中の前記SiO2成分と前記Al2O3成分の合計の含有率が、75質量%以上であり、
前記炭素粒子は、複数の細孔が形成された多孔質粒子であり、
前記酸化物粒子の少なくとも一部は、前記炭素粒子の細孔中に存在するようにしてもよい。 A second recovery step of recovering the carbon-containing powder by separating the hydrophobic liquid from the hydrophobic liquid phase separated in the specific gravity separation step;
The carbon-containing powder contains the carbon particles and the oxide particles,
The carbon component content in the carbon-containing powder is 50% by mass or more and 95% by mass or less,
The oxide particles are particles composed of a compound containing one or both one of the SiO 2 component or Al 2 O 3 component, the total of the said SiO 2 component Al 2 O 3 component of the oxide particles The content of is 75% by mass or more,
The carbon particles are porous particles in which a plurality of pores are formed,
At least a part of the oxide particles may be present in the pores of the carbon particles.
前記炭素含有粉は、前記炭素粒子と前記酸化物粒子を含有し、
前記炭素含有粉中の炭素成分の含有率が、50質量%以上、95質量%以下であり、
前記酸化物粒子は、SiO2成分又はAl2O3成分のうちいずれか一方若しくは双方を含む化合物からなる粒子であり、前記酸化物粒子中の前記SiO2成分と前記Al2O3成分の合計の含有率が、75質量%以上であり、
前記炭素粒子は、複数の細孔が形成された多孔質粒子であり、
前記酸化物粒子の少なくとも一部は、前記炭素粒子の細孔中に存在するようにしてもよい。 A second recovery step of recovering the carbon-containing powder by separating the hydrophobic liquid from the hydrophobic liquid phase separated in the specific gravity separation step;
The carbon-containing powder contains the carbon particles and the oxide particles,
The carbon component content in the carbon-containing powder is 50% by mass or more and 95% by mass or less,
The oxide particles are particles composed of a compound containing one or both one of the SiO 2 component or Al 2 O 3 component, the total of the said SiO 2 component Al 2 O 3 component of the oxide particles The content of is 75% by mass or more,
The carbon particles are porous particles in which a plurality of pores are formed,
At least a part of the oxide particles may be present in the pores of the carbon particles.
前記炭素含有粉に含まれる窒素成分と前記炭素成分の質量比であるN/C比が、0.02以下であるようにしてもよい。
The N / C ratio, which is the mass ratio between the nitrogen component contained in the carbon-containing powder and the carbon component, may be 0.02 or less.
向流型多段連続プロセスにより、前記混合工程と前記比重分離工程の組合せを多段階繰り返すようにしてもよい。
The combination of the mixing step and the specific gravity separation step may be repeated in multiple stages by a countercurrent type multi-stage continuous process.
前記比重分離工程の前、又は前記比重分離工程中に、
疎水性液体又は水のうちいずれか一方若しくは双方と、前記混合物との混合液に対して粉砕処理を行うことにより、当該混合液に含まれる前記炭素粒子を粉砕する粉砕工程
を更に含むようにしてもよい。 Before the specific gravity separation step or during the specific gravity separation step,
A pulverization process for pulverizing the carbon particles contained in the liquid mixture may be further included by performing a pulverization process on the liquid mixture of either or both of the hydrophobic liquid and water and the mixture. .
疎水性液体又は水のうちいずれか一方若しくは双方と、前記混合物との混合液に対して粉砕処理を行うことにより、当該混合液に含まれる前記炭素粒子を粉砕する粉砕工程
を更に含むようにしてもよい。 Before the specific gravity separation step or during the specific gravity separation step,
A pulverization process for pulverizing the carbon particles contained in the liquid mixture may be further included by performing a pulverization process on the liquid mixture of either or both of the hydrophobic liquid and water and the mixture. .
前記粉砕工程において、ビーズを用いた粉砕処理により、前記混合液に含まれる前記炭素粒子を粉砕するようにしてもよい。
In the pulverization step, the carbon particles contained in the mixed solution may be pulverized by a pulverization process using beads.
前記フライアッシュは、石炭を燃焼させることにより生成され、
前記炭素粒子は、前記燃焼時に燃え残った未燃カーボンの粒子であり、
前記酸化物粒子は、前記石炭の灰分が前記燃焼時に溶融して粒状となった粒子であるようにしてもよい。 The fly ash is produced by burning coal,
The carbon particles are unburned carbon particles left unburned during the combustion,
The oxide particles may be particles in which the coal ash is melted and granulated during the combustion.
前記炭素粒子は、前記燃焼時に燃え残った未燃カーボンの粒子であり、
前記酸化物粒子は、前記石炭の灰分が前記燃焼時に溶融して粒状となった粒子であるようにしてもよい。 The fly ash is produced by burning coal,
The carbon particles are unburned carbon particles left unburned during the combustion,
The oxide particles may be particles in which the coal ash is melted and granulated during the combustion.
前記比重分離工程は、
前記混合液を静置することにより、前記炭素粒子を含む疎水性液体相と、前記酸化物粒子を含む水相とに分離する粗分離工程と、
前記粗分離工程で分離された前記疎水性液体相に水を加えて混合し、当該疎水性液体相と水との混合液を静置することにより、前記炭素粒子を含む疎水性液体相と、前記酸化物粒子を含む水相とに分離する水洗浄工程と、
を含むようにしてもよい。 The specific gravity separation step includes:
A rough separation step of separating the liquid mixture into a hydrophobic liquid phase containing the carbon particles and an aqueous phase containing the oxide particles by allowing the mixture to stand.
Water is added to and mixed with the hydrophobic liquid phase separated in the rough separation step, and the liquid mixture of the hydrophobic liquid phase and water is allowed to stand, whereby the hydrophobic liquid phase containing the carbon particles, A water washing step for separating into an aqueous phase containing the oxide particles;
May be included.
前記混合液を静置することにより、前記炭素粒子を含む疎水性液体相と、前記酸化物粒子を含む水相とに分離する粗分離工程と、
前記粗分離工程で分離された前記疎水性液体相に水を加えて混合し、当該疎水性液体相と水との混合液を静置することにより、前記炭素粒子を含む疎水性液体相と、前記酸化物粒子を含む水相とに分離する水洗浄工程と、
を含むようにしてもよい。 The specific gravity separation step includes:
A rough separation step of separating the liquid mixture into a hydrophobic liquid phase containing the carbon particles and an aqueous phase containing the oxide particles by allowing the mixture to stand.
Water is added to and mixed with the hydrophobic liquid phase separated in the rough separation step, and the liquid mixture of the hydrophobic liquid phase and water is allowed to stand, whereby the hydrophobic liquid phase containing the carbon particles, A water washing step for separating into an aqueous phase containing the oxide particles;
May be included.
また、上記課題を解決するために、本発明の別の観点によれば、
前記炭素含有粉を、焼結機、燃焼炉若しくは転炉で使用される石炭の代替として、又はSO2吸着材若しくは脱硝材として利用する、炭素含有粉の利用方法が提供される。 In order to solve the above problem, according to another aspect of the present invention,
There is provided a method for using carbon-containing powder, wherein the carbon-containing powder is used as an alternative to coal used in a sintering machine, a combustion furnace or a converter, or as an SO 2 adsorbent or denitration material.
前記炭素含有粉を、焼結機、燃焼炉若しくは転炉で使用される石炭の代替として、又はSO2吸着材若しくは脱硝材として利用する、炭素含有粉の利用方法が提供される。 In order to solve the above problem, according to another aspect of the present invention,
There is provided a method for using carbon-containing powder, wherein the carbon-containing powder is used as an alternative to coal used in a sintering machine, a combustion furnace or a converter, or as an SO 2 adsorbent or denitration material.
炭素含有粉と他の粉体とを混合し、前記炭素含有粉の嵩比重を大きくした後に、当該炭素含有粉を利用するようにしてもよい。
The carbon-containing powder may be used after mixing the carbon-containing powder with another powder to increase the bulk specific gravity of the carbon-containing powder.
以上説明したように本発明によれば、新規かつ改良された、炭素含有粉と、分離方法及び炭素含有粉の利用方法を提供できる。
As described above, according to the present invention, a new and improved carbon-containing powder, a separation method, and a method of using the carbon-containing powder can be provided.
以下に添付図面を参照しながら、本発明の好適な実施の形態について詳細に説明する。なお、本明細書及び図面において、実質的に同一の機能構成を有する構成要素については、同一の符号を付することにより重複説明を省略する。
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, in this specification and drawing, about the component which has the substantially same function structure, duplication description is abbreviate | omitted by attaching | subjecting the same code | symbol.
[1.本発明の背景及び概要]
まず、本発明に至る背景と、本発明の実施形態に係る炭素含有粉とその製造方法の概要について説明する。 [1. Background and Summary of the Present Invention]
First, the background to the present invention and the outline of the carbon-containing powder and the production method thereof according to the embodiment of the present invention will be described.
まず、本発明に至る背景と、本発明の実施形態に係る炭素含有粉とその製造方法の概要について説明する。 [1. Background and Summary of the Present Invention]
First, the background to the present invention and the outline of the carbon-containing powder and the production method thereof according to the embodiment of the present invention will be described.
前述したように、フライアッシュは、石炭の燃焼により生成される石炭灰の一種であり、例えば、発電所のボイラー等において燃料炭を燃焼させることにより、フライアッシュが生成される。発電所での燃料炭としては、主に瀝青炭又は亜瀝青炭が使用される。
As described above, fly ash is a kind of coal ash generated by the combustion of coal. For example, fly ash is generated by burning fuel coal in a boiler or the like of a power plant. Bituminous coal or subbituminous coal is mainly used as fuel coal at power plants.
フライアッシュは、Al2O3成分、SiO2成分等を含む化合物からなる金属酸化物(灰分)とともに、燃え残った炭素成分である未燃カーボン(炭素成分)を含んでいる。フライアッシュ中の炭素含有率(炭素成分の含有率)は1.5~15質量%であり、SiO2成分、Al2O3成分等の金属酸化物の含有率は75~98質量%である。
The fly ash contains unburned carbon (carbon component), which is a carbon component left unburned, together with a metal oxide (ash) made of a compound containing an Al 2 O 3 component, an SiO 2 component, and the like. The carbon content in the fly ash (carbon component content) is 1.5 to 15% by mass, and the content of metal oxides such as SiO 2 component and Al 2 O 3 component is 75 to 98% by mass. .
発電所等における石炭の燃焼過程において、燃料炭中のSiO2成分、Al2O3成分等の酸化物は一時的に溶融するため、燃焼後のフライアッシュ中では、当該酸化物は、表面に凹凸が少ない略球状の粒子として存在している。ここでいう略球状とは、真球状に限定されず、表面に凹凸が少なく概ね球に近い形状であればよく、楕円体状、多角球状などの形状も含まれる。酸化物粒子の粒子径は、概ね直径200μm以下であり、直径1μm未満の酸化物粒子も5~10質量%含まれることが多い。かかる酸化物粒子は、後述する未燃カーボン粒子のような多孔質粒子とは異なり、ほとんどが略球状の中実粒子であり、酸化物粒子の表層に細孔は形成されていない。このようにフライアッシュは略球状で中実の酸化物粒子を多く含むため、フライアッシュの比表面積は、0.5~10m2/gと小さくなっている。なお、フライアッシュの粒子径は約1~200μmである。
During the combustion process of coal in power plants, etc., oxides such as SiO 2 component and Al 2 O 3 component in the fuel coal are temporarily melted. Therefore, in the fly ash after combustion, the oxide is on the surface. It exists as almost spherical particles with few irregularities. The substantially spherical shape here is not limited to a true spherical shape, and may be any shape that has almost no irregularities on the surface and is almost similar to a sphere, and includes shapes such as an ellipsoidal shape and a polygonal spherical shape. The particle diameter of the oxide particles is generally 200 μm or less, and oxide particles having a diameter of less than 1 μm are often included in an amount of 5 to 10% by mass. Unlike porous particles such as unburned carbon particles, which will be described later, most of these oxide particles are substantially spherical solid particles, and no pores are formed on the surface layer of the oxide particles. Thus, fly ash is substantially spherical and contains a lot of solid oxide particles, so the specific surface area of fly ash is as small as 0.5 to 10 m 2 / g. The fly ash has a particle size of about 1 to 200 μm.
一方、瀝青炭、亜瀝青炭からコークスを製造する場合、コークス炉等で瀝青炭、亜瀝青炭が乾留処理される。この乾留処理では、加熱によって揮発分が消失する際に生じる空隙のため、乾留物の比表面積が大きくなることが分かっている(非特許文献1)。
非特許文献1:行本 剛、外3名、“石炭とコークスの鑑別”、財務省関税中央分析所報、Vol.49 pp.69-76、2011年3月19日 On the other hand, when producing coke from bituminous coal and subbituminous coal, bituminous coal and subbituminous coal are subjected to dry distillation treatment in a coke oven or the like. In this dry distillation treatment, it is known that the specific surface area of the dry distillation product is increased due to voids generated when volatile components disappear by heating (Non-patent Document 1).
Non-Patent Document 1: Tsuyoshi Yukimoto, 3 others, “Difference between coal and coke”, Ministry of Finance Customs Central Analysis Bulletin, Vol. 49 pp. 69-76, March 19, 2011
非特許文献1:行本 剛、外3名、“石炭とコークスの鑑別”、財務省関税中央分析所報、Vol.49 pp.69-76、2011年3月19日 On the other hand, when producing coke from bituminous coal and subbituminous coal, bituminous coal and subbituminous coal are subjected to dry distillation treatment in a coke oven or the like. In this dry distillation treatment, it is known that the specific surface area of the dry distillation product is increased due to voids generated when volatile components disappear by heating (Non-patent Document 1).
Non-Patent Document 1: Tsuyoshi Yukimoto, 3 others, “Difference between coal and coke”, Ministry of Finance Customs Central Analysis Bulletin, Vol. 49 pp. 69-76, March 19, 2011
しかしながら、発電所のボイラー内で石炭は燃焼状態となり、上記コークス炉内のような乾留状態とは異なるので、従来では、フライアッシュ中の未燃カーボン粒子の表面に賦活が進んでいるかどうかは不明であった。さらに、乾燥状態において、微細な酸化物粒子は、その粒子径が小さいほど、ファンデルワールス力や静電気力などの引力で、他の粒子と凝集しやすく、かつ、フライアッシュ中における未燃カーボン粒子の含有率は少ない。このため、未燃カーボン粒子の表面に多数の酸化物粒子が付着してしまう。このため、ボイラー内で燃え残った未燃カーボン粒子の単独の特徴は解明できていなかった。
However, since the coal is in a combustion state in the boiler of the power plant and is different from the dry distillation state as in the above coke oven, it is conventionally unknown whether the activation has progressed to the surface of the unburned carbon particles in the fly ash. Met. Furthermore, in the dry state, finer oxide particles are more likely to aggregate with other particles due to attractive forces such as van der Waals force and electrostatic force as the particle size is smaller, and unburned carbon particles in fly ash. The content of is small. For this reason, many oxide particles adhere to the surface of the unburned carbon particles. For this reason, the single feature of the unburned carbon particles left unburned in the boiler has not been elucidated.
さらに、仮に未燃カーボン粒子の表層に賦活により細孔が存在していたとしても、微細な酸化物粒子が当該細孔に入り込み、ファンデルスワールス力や静電気力などの引力で付着する。このため、未燃カーボン粒子の細孔から酸化物粒子を除去することが困難であるので、未燃カーボン粒子の単独の特徴を解明することがさらに困難になっていた。
Furthermore, even if pores exist in the surface layer of unburned carbon particles due to activation, fine oxide particles enter the pores and adhere with attractive forces such as van der Waals force or electrostatic force. For this reason, it is difficult to remove the oxide particles from the pores of the unburned carbon particles, and it has become more difficult to elucidate the characteristics of the unburned carbon particles alone.
上記のような状況において、本発明者は、特殊な湿式分離方法を使用して、フライアッシュ中の未燃カーボン粒子を酸化物粒子から好適に分離し、未燃カーボン粒子が濃縮された炭素含有粉を製造する方法を見出し、当該方法により製造された炭素含有粉の特性について調査及び分析し、新たな種々の特徴を見出した。
In the above situation, the present inventor uses a special wet separation method to suitably separate the unburned carbon particles in the fly ash from the oxide particles, and the carbon containing enriched unburned carbon particles. A method for producing the powder was found, and the characteristics of the carbon-containing powder produced by the method were investigated and analyzed, and various new characteristics were found.
具体的には、まず、発電所のボイラー等での燃焼後のフライアッシュ(石炭灰)の窒素含有率は低く、当該フライアッシュのN/C比は0.02以下であることが分かった。そして、フライアッシュは、未燃カーボン粒子(炭素成分)と、SiO2成分、Al2O3成分等を含む化合物からなる酸化物粒子(灰分)を含有しているが、図1A及び図1B(以下、図1と総称する。)に示すように、未燃カーボン粒子P2は、多孔質粒子であり、未燃カーボン粒子P2の表層には多数の細孔P20が形成されていることが分かった。さらに、酸化物粒子P1は、略球状の中実粒子であり、未燃カーボン粒子P2の表面に付着している場合もあれば、未燃カーボン粒子P2の表層に形成された複数の細孔P20の内部に入り込んで存在している場合もあることが分かった。
Specifically, first, it was found that the nitrogen content of fly ash (coal ash) after combustion in a boiler of a power plant is low, and the N / C ratio of the fly ash is 0.02 or less. The fly ash contains unburned carbon particles (carbon component) and oxide particles (ash) composed of a compound containing SiO 2 component, Al 2 O 3 component, etc., but FIG. 1A and FIG. 1B ( Hereinafter, as shown in FIG. 1), the unburned carbon particles P2 were porous particles, and it was found that a large number of pores P20 were formed on the surface layer of the unburned carbon particles P2. . Further, the oxide particles P1 are substantially spherical solid particles, and may be attached to the surface of the unburned carbon particles P2, or may be a plurality of pores P20 formed in the surface layer of the unburned carbon particles P2. It has been found that there are cases where it exists inside of.
そこで、図1に示すように、未燃カーボン粒子P2と酸化物粒子P1が混在しているフライアッシュから、未燃カーボン粒子P2を分離して濃縮するために、本実施形態に係る炭素含有粉の製造方法では、以下のような特殊な湿式分離方法を利用する。
Therefore, as shown in FIG. 1, in order to separate and concentrate the unburned carbon particles P2 from the fly ash in which the unburned carbon particles P2 and the oxide particles P1 are mixed, the carbon-containing powder according to this embodiment is used. In this manufacturing method, the following special wet separation method is used.
まず、水と、疎水性液体(例えば疎水性を有する有機溶剤)と、フライアッシュとを混合・撹拌した混合液を静置することにより、未燃カーボン粒子P2を含む疎水性液体相と、酸化物粒子P1を含む水相とに分離する(比重分離工程)。次いで、疎水性液体相から疎水性液体を分離することにより、未燃カーボン粒子P2を含むケーキを回収する(固液分離工程)。その後、当該ケーキを加熱して疎水性液体を揮発させることにより、未燃カーボン粒子P2が濃縮された炭素含有粉を回収する(回収工程)。
First, a liquid mixture obtained by mixing and stirring water, a hydrophobic liquid (for example, an organic solvent having hydrophobicity), and fly ash is allowed to stand, so that a hydrophobic liquid phase containing unburned carbon particles P2 is oxidized. It isolate | separates into the water phase containing the product particle P1 (specific gravity separation process). Next, the cake containing unburned carbon particles P2 is recovered by separating the hydrophobic liquid from the hydrophobic liquid phase (solid-liquid separation step). Thereafter, the cake is heated to volatilize the hydrophobic liquid, thereby collecting the carbon-containing powder in which the unburned carbon particles P2 are concentrated (recovery step).
かかる製造方法により、フライアッシュから未燃カーボン粒子P2を分離及び濃縮し、炭素含有率の高い炭素含有粉(炭素含有率:50質量%以上)を得ることができる。この分離方法では、図2A及び図2B(以下、図2と総称する。)に示すように、未燃カーボン粒子P2の細孔P20に入り込んでいる微細な酸化物粒子P1は、あまり除去されないものの、未燃カーボン粒子P2の表面に付着している酸化物粒子P1のほとんどを、分離及び除去することができる。
By such a production method, unburned carbon particles P2 can be separated and concentrated from fly ash to obtain a carbon-containing powder having a high carbon content (carbon content: 50% by mass or more). In this separation method, as shown in FIGS. 2A and 2B (hereinafter collectively referred to as FIG. 2), the fine oxide particles P1 entering the pores P20 of the unburned carbon particles P2 are not so much removed. Most of the oxide particles P1 adhering to the surface of the unburned carbon particles P2 can be separated and removed.
さらに、上記比重分離工程の前工程又は後工程で、上記水又は疎水性液体のうちいずれか一方若しくは双方とフライアッシュとの混合液に対して粉砕処理を施すことが好ましい(粉砕工程)。なお、粉砕方法としては、例えば、超音波による粉砕処理、高速せん断ミキサーによる粉砕処理、ボールミル又はビーズミルによる粉砕処理などが挙げられる。なお、上記粉砕工程で用いる疎水性液体は、上記比重分離工程で用いる疎水性液体L2と同じであってもよいし、異なっていてもよい。
Furthermore, it is preferable to pulverize the mixed liquid of either one or both of the water and the hydrophobic liquid and fly ash in the pre-process or post-process of the specific gravity separation process (pulverization process). Examples of the pulverization method include a pulverization process using ultrasonic waves, a pulverization process using a high-speed shear mixer, and a pulverization process using a ball mill or a bead mill. Note that the hydrophobic liquid used in the pulverization step may be the same as or different from the hydrophobic liquid L2 used in the specific gravity separation step.
かかる粉砕処理により、図3A及び図3B(以下、図3と総称する。)に示すように、フライアッシュ中の未燃カーボン粒子P2が粉砕され、破断面P21で複数片に分割され、微細化される。これにより、破断面P21付近の細孔P20中に入り込んでいた略球状の酸化物粒子P1が、当該細孔P20から放出される。従って、未燃カーボン粒子P2の表面に付着していた酸化物粒子P1のみならず、細孔P20中に入り込んでいた酸化物粒子P1も、未燃カーボン粒子P2から分離及び除去されるので、未燃カーボン粒子P2と酸化物粒子P1をさらに好適に分離できる。これにより、フライアッシュに粉砕処理を施すことで、炭素含有率がより一層高い炭素含有粉(炭素含有率:70質量%以上)を得ることが可能となる。
As shown in FIGS. 3A and 3B (hereinafter collectively referred to as FIG. 3), the unburned carbon particles P2 in the fly ash are pulverized and divided into a plurality of pieces at the fracture surface P21. Is done. Thereby, the substantially spherical oxide particles P1 that have entered the pores P20 near the fracture surface P21 are released from the pores P20. Therefore, not only the oxide particles P1 that have adhered to the surface of the unburned carbon particles P2, but also the oxide particles P1 that have entered the pores P20 are separated and removed from the unburned carbon particles P2. The fuel carbon particles P2 and the oxide particles P1 can be more preferably separated. Thereby, it becomes possible to obtain a carbon-containing powder (carbon content: 70% by mass or more) having an even higher carbon content by subjecting fly ash to pulverization.
[2.炭素含有粉の構成]
次に、本実施形態に係るフライアッシュから分離・回収された未燃カーボン粒子を主体とする炭素含有粉の構成について詳細に説明する。 [2. Composition of carbon-containing powder]
Next, the configuration of the carbon-containing powder mainly composed of unburned carbon particles separated and collected from the fly ash according to the present embodiment will be described in detail.
次に、本実施形態に係るフライアッシュから分離・回収された未燃カーボン粒子を主体とする炭素含有粉の構成について詳細に説明する。 [2. Composition of carbon-containing powder]
Next, the configuration of the carbon-containing powder mainly composed of unburned carbon particles separated and collected from the fly ash according to the present embodiment will be described in detail.
[2.1.炭素含有粉の特性]
上記の製造方法によりフライアッシュから回収された炭素含有粉(炭素含有率:50質量%以上)の成分、物性値等を調査・分析した結果、当該炭素含有粉は以下の特性を有することが判明した。以下では、表1を参照して、本実施形態に係る炭素含有粉の特性を、従来の炭素含有物質と比較しながら説明する。 [2.1. Characteristics of carbon-containing powder]
As a result of investigating and analyzing the components, physical properties, etc. of the carbon-containing powder (carbon content: 50% by mass or more) recovered from fly ash by the above manufacturing method, it was found that the carbon-containing powder has the following characteristics: did. Below, with reference to Table 1, the characteristic of the carbon containing powder which concerns on this embodiment is demonstrated, comparing with the conventional carbon containing substance.
上記の製造方法によりフライアッシュから回収された炭素含有粉(炭素含有率:50質量%以上)の成分、物性値等を調査・分析した結果、当該炭素含有粉は以下の特性を有することが判明した。以下では、表1を参照して、本実施形態に係る炭素含有粉の特性を、従来の炭素含有物質と比較しながら説明する。 [2.1. Characteristics of carbon-containing powder]
As a result of investigating and analyzing the components, physical properties, etc. of the carbon-containing powder (carbon content: 50% by mass or more) recovered from fly ash by the above manufacturing method, it was found that the carbon-containing powder has the following characteristics: did. Below, with reference to Table 1, the characteristic of the carbon containing powder which concerns on this embodiment is demonstrated, comparing with the conventional carbon containing substance.
(1)N/C比
N/C比は、ある材料中に占める窒素成分の量(窒素含有率)と、炭素成分の量(炭素含有率)との質量比率であり、窒素含有率を炭素含有率で除算して求められる。本実施形態に係る炭素含有粉は、窒素含有率が低く、かつ、炭素含有率が高いので、当該炭素含有粉のN/C比は、0超、0.02以下であり、例えば、0.0065~0.0196の範囲内である。表1には記載していないが、無煙炭、瀝青炭、亜瀝青炭のN/C比は、例えば0.008~0.03であるが、0.02超であるものが多い。本実施形態に係る炭素含有粉のN/C比は、無煙炭、瀝青炭、亜瀝青炭のN/C比の中でも、低い領域に相当する。本実施形態に係る湿式分離工程前の元々のフライアッシュに含まれる未燃カーボンのN/C比は、0.02以下であり、窒素含有率が低い。このため、分離回収された未燃カーボンを主体とする炭素含有粉のN/C比も、0.02以下となる。後述するが、発電所のボイラー内の燃焼温度が上昇するに従い、N/C比は低下すると考えられる。 (1) N / C ratio The N / C ratio is a mass ratio between the amount of nitrogen component (nitrogen content) and the amount of carbon component (carbon content) in a certain material. It is obtained by dividing by the content rate. Since the carbon-containing powder according to this embodiment has a low nitrogen content and a high carbon content, the N / C ratio of the carbon-containing powder is more than 0 and 0.02 or less. It is within the range of 0065 to 0.0196. Although not described in Table 1, the N / C ratio of anthracite, bituminous coal, and sub-bituminous coal is, for example, 0.008 to 0.03, but many of them are over 0.02. The N / C ratio of the carbon-containing powder according to the present embodiment corresponds to a low region among the N / C ratios of anthracite, bituminous coal, and sub-bituminous coal. The N / C ratio of the unburned carbon contained in the original fly ash before the wet separation process according to this embodiment is 0.02 or less, and the nitrogen content is low. For this reason, the N / C ratio of the carbon-containing powder mainly composed of unburned carbon separated and recovered is also 0.02 or less. As will be described later, it is considered that the N / C ratio decreases as the combustion temperature in the boiler of the power plant increases.
N/C比は、ある材料中に占める窒素成分の量(窒素含有率)と、炭素成分の量(炭素含有率)との質量比率であり、窒素含有率を炭素含有率で除算して求められる。本実施形態に係る炭素含有粉は、窒素含有率が低く、かつ、炭素含有率が高いので、当該炭素含有粉のN/C比は、0超、0.02以下であり、例えば、0.0065~0.0196の範囲内である。表1には記載していないが、無煙炭、瀝青炭、亜瀝青炭のN/C比は、例えば0.008~0.03であるが、0.02超であるものが多い。本実施形態に係る炭素含有粉のN/C比は、無煙炭、瀝青炭、亜瀝青炭のN/C比の中でも、低い領域に相当する。本実施形態に係る湿式分離工程前の元々のフライアッシュに含まれる未燃カーボンのN/C比は、0.02以下であり、窒素含有率が低い。このため、分離回収された未燃カーボンを主体とする炭素含有粉のN/C比も、0.02以下となる。後述するが、発電所のボイラー内の燃焼温度が上昇するに従い、N/C比は低下すると考えられる。 (1) N / C ratio The N / C ratio is a mass ratio between the amount of nitrogen component (nitrogen content) and the amount of carbon component (carbon content) in a certain material. It is obtained by dividing by the content rate. Since the carbon-containing powder according to this embodiment has a low nitrogen content and a high carbon content, the N / C ratio of the carbon-containing powder is more than 0 and 0.02 or less. It is within the range of 0065 to 0.0196. Although not described in Table 1, the N / C ratio of anthracite, bituminous coal, and sub-bituminous coal is, for example, 0.008 to 0.03, but many of them are over 0.02. The N / C ratio of the carbon-containing powder according to the present embodiment corresponds to a low region among the N / C ratios of anthracite, bituminous coal, and sub-bituminous coal. The N / C ratio of the unburned carbon contained in the original fly ash before the wet separation process according to this embodiment is 0.02 or less, and the nitrogen content is low. For this reason, the N / C ratio of the carbon-containing powder mainly composed of unburned carbon separated and recovered is also 0.02 or less. As will be described later, it is considered that the N / C ratio decreases as the combustion temperature in the boiler of the power plant increases.
(2)炭素含有率
本実施形態に係る製造方法によりフライアッシュから湿式分離により回収される炭素含有粉の炭素含有率CAは、50質量%以上、95質量%以下である。特に、上記粉砕工程を含む製造方法により回収される炭素含有粉の炭素含有率CAは、70質量%以上、95質量%以下である。 (2) carbon content C A of the carbon-containing powder is recovered by a wet separation from the fly ash by the production method according to the carbon content present embodiment is preferably 50 mass% or more and 95 mass% or less. In particular, the carbon content C A of the carbon-containing powder is recovered by a production method comprising the above grinding process, 70 mass% or more and 95 mass% or less.
本実施形態に係る製造方法によりフライアッシュから湿式分離により回収される炭素含有粉の炭素含有率CAは、50質量%以上、95質量%以下である。特に、上記粉砕工程を含む製造方法により回収される炭素含有粉の炭素含有率CAは、70質量%以上、95質量%以下である。 (2) carbon content C A of the carbon-containing powder is recovered by a wet separation from the fly ash by the production method according to the carbon content present embodiment is preferably 50 mass% or more and 95 mass% or less. In particular, the carbon content C A of the carbon-containing powder is recovered by a production method comprising the above grinding process, 70 mass% or more and 95 mass% or less.
従って、本実施形態に係る製造方法により製造される炭素含有粉においては、炭素含有率CAは、50質量%以上、より好ましくは70質量%以上であり、N/C比も0.02以下と小さい。従って、本実施形態に係る炭素含有粉は、窒素含有率が低い石炭(低窒素炭)として利用でき、焼結機、発電所、転炉等の石炭処理設備で使用される従来の低窒素炭の代替物として有効利用できる。特に、焼結機で使用する低窒素炭の代替物として有効利用するには、N/C比が0.015以下であることがより好ましい。このため、本実施形態に係る製造方法により、低窒素炭と同程度の高い炭素含有率と、低いN/C比を有する炭素含有粉を、フライアッシュから回収してリサイクルできることは、産業上非常に重要かつ有益である。
Accordingly, in the carbon-containing powder produced by the production method according to the present embodiment, the carbon content C A, 50 wt% or more, more is preferably 70 mass% or more, N / C ratio is also 0.02 or less And small. Therefore, the carbon-containing powder according to the present embodiment can be used as coal having a low nitrogen content (low nitrogen coal) and is used in conventional coal processing facilities such as a sintering machine, a power plant, and a converter. It can be used effectively as an alternative. In particular, the N / C ratio is more preferably 0.015 or less for effective use as an alternative to low nitrogen coal used in a sintering machine. For this reason, the production method according to the present embodiment makes it possible to collect and recycle carbon-containing powder having a high carbon content rate as low as low nitrogen coal and a low N / C ratio from fly ash. Important and beneficial to.
(3)比表面積
図2及び図3に示すように、本実施形態に係る炭素含有粉に含まれる未燃カーボン粒子P2は、その表層に多数の細孔P20が形成された多孔質粒子である。このため、本実施形態に係る炭素含有粉の比表面積は、活性コークス粉と同等の50~300m2/gであり、分離処理前のフライアッシュの比表面積(0.5~10m2/g)よりも、数十倍~百倍程度も大きくなっている。 (3) Specific surface area As shown in FIG.2 and FIG.3, the unburned carbon particle P2 contained in the carbon containing powder which concerns on this embodiment is a porous particle by which many pores P20 were formed in the surface layer. . For this reason, the specific surface area of the carbon-containing powder according to the present embodiment is 50 to 300 m 2 / g equivalent to the activated coke powder, and the specific surface area of the fly ash before the separation treatment (0.5 to 10 m 2 / g) It is several tens to one hundred times larger than that.
図2及び図3に示すように、本実施形態に係る炭素含有粉に含まれる未燃カーボン粒子P2は、その表層に多数の細孔P20が形成された多孔質粒子である。このため、本実施形態に係る炭素含有粉の比表面積は、活性コークス粉と同等の50~300m2/gであり、分離処理前のフライアッシュの比表面積(0.5~10m2/g)よりも、数十倍~百倍程度も大きくなっている。 (3) Specific surface area As shown in FIG.2 and FIG.3, the unburned carbon particle P2 contained in the carbon containing powder which concerns on this embodiment is a porous particle by which many pores P20 were formed in the surface layer. . For this reason, the specific surface area of the carbon-containing powder according to the present embodiment is 50 to 300 m 2 / g equivalent to the activated coke powder, and the specific surface area of the fly ash before the separation treatment (0.5 to 10 m 2 / g) It is several tens to one hundred times larger than that.
(4)SO2吸着能、脱硝能
上記のように、本実施形態に係る炭素含有粉の比表面積は、50~300m2/gと非常に大きい。このため、本実施形態に係る炭素含有粉は、SO2吸着能及び脱硝能を有しており、SO2吸着材及び脱硝材として有効利用することができる。 (4) SO 2 adsorption capacity and denitration capacity As described above, the specific surface area of the carbon-containing powder according to the present embodiment is as large as 50 to 300 m 2 / g. For this reason, the carbon-containing powder according to the present embodiment has SO 2 adsorption capacity and denitration capacity, and can be effectively used as an SO 2 adsorption material and denitration material.
上記のように、本実施形態に係る炭素含有粉の比表面積は、50~300m2/gと非常に大きい。このため、本実施形態に係る炭素含有粉は、SO2吸着能及び脱硝能を有しており、SO2吸着材及び脱硝材として有効利用することができる。 (4) SO 2 adsorption capacity and denitration capacity As described above, the specific surface area of the carbon-containing powder according to the present embodiment is as large as 50 to 300 m 2 / g. For this reason, the carbon-containing powder according to the present embodiment has SO 2 adsorption capacity and denitration capacity, and can be effectively used as an SO 2 adsorption material and denitration material.
(5)酸化物粒子の成分
酸化物粒子P1は、少なくともSiO2成分又はAl2O3成分のうちいずれか一方若しくは双方を含む化合物からなる粒子である。フライアッシュ中において、SiとAlは、主に、mullite(Al6Si2O13)、quartz(SiO2)、amorphous(nAl2O3・mSiO2)等の化合物として含まれる。ただし、n、mは正数である。これら化合物は、SiO2成分又はAl2O3成分に相当する。フライアッシュ中には、かかる化合物からなる酸化物粒子P1が含まれている。このため、当該フライアッシュから分離された炭素含有粉にも、一部残存した、当該化合物からなる酸化物粒子P1が含まれることになる。 (5) Components of oxide particles The oxide particles P1 are particles made of a compound containing at least one of or both of a SiO 2 component and an Al 2 O 3 component. In fly ash, Si and Al are mainly contained as compounds such as mullite (Al 6 Si 2 O 13 ), quartz (SiO 2 ), and amorphous (nAl 2 O 3 .mSiO 2 ). However, n and m are positive numbers. These compounds correspond to the SiO 2 component or the Al 2 O 3 component. The fly ash contains oxide particles P1 made of such a compound. For this reason, the carbon-containing powder separated from the fly ash also contains the remaining oxide particles P1 made of the compound.
酸化物粒子P1は、少なくともSiO2成分又はAl2O3成分のうちいずれか一方若しくは双方を含む化合物からなる粒子である。フライアッシュ中において、SiとAlは、主に、mullite(Al6Si2O13)、quartz(SiO2)、amorphous(nAl2O3・mSiO2)等の化合物として含まれる。ただし、n、mは正数である。これら化合物は、SiO2成分又はAl2O3成分に相当する。フライアッシュ中には、かかる化合物からなる酸化物粒子P1が含まれている。このため、当該フライアッシュから分離された炭素含有粉にも、一部残存した、当該化合物からなる酸化物粒子P1が含まれることになる。 (5) Components of oxide particles The oxide particles P1 are particles made of a compound containing at least one of or both of a SiO 2 component and an Al 2 O 3 component. In fly ash, Si and Al are mainly contained as compounds such as mullite (Al 6 Si 2 O 13 ), quartz (SiO 2 ), and amorphous (nAl 2 O 3 .mSiO 2 ). However, n and m are positive numbers. These compounds correspond to the SiO 2 component or the Al 2 O 3 component. The fly ash contains oxide particles P1 made of such a compound. For this reason, the carbon-containing powder separated from the fly ash also contains the remaining oxide particles P1 made of the compound.
本実施形態に係る炭素含有粉は、未燃カーボン(炭素成分)を主体とする粉体であるが、後述する比重分離処理により分離しきれなかった酸化物粒子P1も含有している。炭素含有粉中の酸化物粒子P1の含有率は、50質量%未満、好ましくは30質量%未満である。酸化物粒子P1中のSiO2成分とAl2O3成分の合計の含有率は、75質量%以上、98質量%以下である。このように、酸化物粒子P1は、SiO2成分とAl2O3成分を主体とする化合物からなるが、それ以外にも他の元素の酸化物が含まれていてもよい。上記酸化物粒子P1中のSiO2成分の含有率は、50質量%以上、80質量%以下であり、当該酸化物粒子P1中のAl2O3成分の含有率は、10質量%以上、30質量%以下である。なお、これらの含有率としては、「平均含有率」を用いることが好ましい。平均含有率は、複数個の酸化物粒子P1のサンプルを用いてSiO2成分とAl2O3成分の含有率を測定し、当該複数の測定値の平均を算出することにより得られる。
The carbon-containing powder according to the present embodiment is a powder mainly composed of unburned carbon (carbon component), but also contains oxide particles P1 that could not be separated by the specific gravity separation process described later. The content rate of the oxide particles P1 in the carbon-containing powder is less than 50% by mass, preferably less than 30% by mass. The total content of the SiO 2 component and the Al 2 O 3 component in the oxide particles P1 is 75% by mass or more and 98% by mass or less. Thus, the oxide particles P1, but a compound consisting mainly of SiO 2 component and Al 2 O 3 component may contain oxides of other elements besides that. The content of the SiO 2 component in the oxide particles P1 is 50% by mass or more and 80% by mass or less, and the content of the Al 2 O 3 component in the oxide particles P1 is 10% by mass or more, 30%. It is below mass%. In addition, it is preferable to use "average content rate" as these content rates. The average content rate is obtained by measuring the content rates of the SiO 2 component and the Al 2 O 3 component using a sample of the plurality of oxide particles P1, and calculating the average of the plurality of measured values.
(6)酸化物粒子の粒子径、円形度と存在形態
本実施形態に係る炭素含有粉には、未燃カーボン粒子P2のみならず、酸化物粒子P1も混在している。これら酸化物粒子P1は、上記のように石炭をボイラー等で燃焼させるときに、石炭の灰分が燃焼熱で溶融した後に、冷えて粒状となった粒子であり、ほとんどが略球状の中実粒子である。酸化物粒子P1の粒子径は、体積基準の50%粒子径(メジアン径 D50)で、1~20μmである。酸化物粒子P1の円形度の平均値は、0.9超、1以下である。ここで粒子の円形度とは、粒子の投影像の周囲長に対する、粒子の投影像と面積が等しい円の周囲長の、比である。 (6) Particle diameter, circularity and existence form of oxide particles The carbon-containing powder according to the present embodiment contains not only unburned carbon particles P2 but also oxide particles P1. These oxide particles P1 are particles that are cooled and granular after coal ash is melted by combustion heat when the coal is burned in a boiler or the like as described above, and are almost solid solid particles. It is. The particle diameter of the oxide particles P1 is 1 to 20 μm in terms of a 50% particle diameter (median diameter D50) based on volume. The average value of the circularity of the oxide particles P1 is more than 0.9 and 1 or less. Here, the circularity of the particle is the ratio of the circumference of a circle having the same area as the projected image of the particle to the circumference of the projected image of the particle.
本実施形態に係る炭素含有粉には、未燃カーボン粒子P2のみならず、酸化物粒子P1も混在している。これら酸化物粒子P1は、上記のように石炭をボイラー等で燃焼させるときに、石炭の灰分が燃焼熱で溶融した後に、冷えて粒状となった粒子であり、ほとんどが略球状の中実粒子である。酸化物粒子P1の粒子径は、体積基準の50%粒子径(メジアン径 D50)で、1~20μmである。酸化物粒子P1の円形度の平均値は、0.9超、1以下である。ここで粒子の円形度とは、粒子の投影像の周囲長に対する、粒子の投影像と面積が等しい円の周囲長の、比である。 (6) Particle diameter, circularity and existence form of oxide particles The carbon-containing powder according to the present embodiment contains not only unburned carbon particles P2 but also oxide particles P1. These oxide particles P1 are particles that are cooled and granular after coal ash is melted by combustion heat when the coal is burned in a boiler or the like as described above, and are almost solid solid particles. It is. The particle diameter of the oxide particles P1 is 1 to 20 μm in terms of a 50% particle diameter (median diameter D50) based on volume. The average value of the circularity of the oxide particles P1 is more than 0.9 and 1 or less. Here, the circularity of the particle is the ratio of the circumference of a circle having the same area as the projected image of the particle to the circumference of the projected image of the particle.
かかる酸化物粒子P1の少なくとも一部は、上記未燃カーボン粒子P2の表層に形成された多数の細孔P20中に入り込んで存在している。後述する比重分離処理により表面から酸化物粒子P1が分離された炭素含有粉の内部における、細孔P20中に残った酸化物粒子P1及び細孔P20外に含まれる酸化物粒子P1の含有率は、5質量%超、50質量%未満でありうる。このように、本実施形態に係る炭素含有粉は、多孔質な未燃カーボン粒子P2の細孔P20中に、50%粒子径が1~20μmであり、円形度の平均値が0.9超、1以下であるような粒状酸化物(略球状の酸化物粒子P1)が混在するという特徴的な構成を有している。このような特徴的構成を有する炭素含有粉は、従来知られておらず、新規かつ有用な低窒素炭粉であるといえる。
At least a part of the oxide particles P1 is present in a large number of pores P20 formed in the surface layer of the unburned carbon particles P2. The content of the oxide particles P1 remaining in the pores P20 and the oxide particles P1 contained outside the pores P20 in the carbon-containing powder from which the oxide particles P1 are separated from the surface by the specific gravity separation process described later is It may be more than 5% by mass and less than 50% by mass. As described above, the carbon-containing powder according to the present embodiment has a 50% particle diameter of 1 to 20 μm in the pores P20 of the porous unburned carbon particles P2, and the average value of the circularity exceeds 0.9. 1 or less, the particulate oxide (substantially spherical oxide particles P1) is mixed. The carbon-containing powder having such a characteristic configuration has not been conventionally known, and can be said to be a novel and useful low nitrogen carbon powder.
[2.2.測定方法]
次に、本実施形態に係る炭素含有粉の上記特性の測定方法について説明する。 [2.2. Measuring method]
Next, the measuring method of the said characteristic of the carbon containing powder which concerns on this embodiment is demonstrated.
次に、本実施形態に係る炭素含有粉の上記特性の測定方法について説明する。 [2.2. Measuring method]
Next, the measuring method of the said characteristic of the carbon containing powder which concerns on this embodiment is demonstrated.
(1)比表面積の測定方法
流動式比表面積測定装置(例えば、島津製作所社製:FlowSorb II 2300)を用いて、ガス吸着法により、多孔質な未燃カーボン粒子を主体とする炭素含有粉の比表面積(単位:m2/g)を測定することができる。ガス吸着法では、ヘリウムと窒素の混合ガス(体積比7:3)を用い、BETの式を用いてガスの単分子吸着量と比表面積を算出することができる。 (1) Measuring method of specific surface area Using a flow-type specific surface area measuring device (for example, FlowSorb II 2300, manufactured by Shimadzu Corporation), a carbon-containing powder mainly composed of porous unburned carbon particles is obtained by a gas adsorption method. The specific surface area (unit: m 2 / g) can be measured. In the gas adsorption method, a gas mixture of helium and nitrogen (volume ratio 7: 3) is used, and the monomolecular adsorption amount and specific surface area of the gas can be calculated using the BET equation.
流動式比表面積測定装置(例えば、島津製作所社製:FlowSorb II 2300)を用いて、ガス吸着法により、多孔質な未燃カーボン粒子を主体とする炭素含有粉の比表面積(単位:m2/g)を測定することができる。ガス吸着法では、ヘリウムと窒素の混合ガス(体積比7:3)を用い、BETの式を用いてガスの単分子吸着量と比表面積を算出することができる。 (1) Measuring method of specific surface area Using a flow-type specific surface area measuring device (for example, FlowSorb II 2300, manufactured by Shimadzu Corporation), a carbon-containing powder mainly composed of porous unburned carbon particles is obtained by a gas adsorption method. The specific surface area (unit: m 2 / g) can be measured. In the gas adsorption method, a gas mixture of helium and nitrogen (volume ratio 7: 3) is used, and the monomolecular adsorption amount and specific surface area of the gas can be calculated using the BET equation.
(2)SO2吸着能の測定方法
反応槽内に炭素含有粉(試料)を5~50ml入れ、反応槽温度を100℃にし、試料ガスを3時間通気する。試料ガスの組成は、SO2:2体積%、H2O:10体積%、O2:6体積%、残りを窒素とすることができる。試料ガスの通気後、窒素気流下で400℃に炭素含有粉を加熱し、発生するSO2を捕集して定量することで、炭素含有粉によるSO2の吸着能(単位:mg-SO2/g-炭素含有粉)を測定できる。 (2) Measuring method of SO 2 adsorption capacity 5-50 ml of carbon-containing powder (sample) is placed in the reaction vessel, the reaction vessel temperature is 100 ° C., and the sample gas is aerated for 3 hours. The composition of the sample gas can be SO 2 : 2% by volume, H 2 O: 10% by volume, O 2 : 6% by volume, and the rest can be nitrogen. After aeration of the sample gas, the carbon-containing powder is heated to 400 ° C. under a nitrogen stream, and the generated SO 2 is collected and quantified, so that the adsorption capacity of SO 2 by the carbon-containing powder (unit: mg-SO 2). / G-carbon-containing powder).
反応槽内に炭素含有粉(試料)を5~50ml入れ、反応槽温度を100℃にし、試料ガスを3時間通気する。試料ガスの組成は、SO2:2体積%、H2O:10体積%、O2:6体積%、残りを窒素とすることができる。試料ガスの通気後、窒素気流下で400℃に炭素含有粉を加熱し、発生するSO2を捕集して定量することで、炭素含有粉によるSO2の吸着能(単位:mg-SO2/g-炭素含有粉)を測定できる。 (2) Measuring method of SO 2 adsorption capacity 5-50 ml of carbon-containing powder (sample) is placed in the reaction vessel, the reaction vessel temperature is 100 ° C., and the sample gas is aerated for 3 hours. The composition of the sample gas can be SO 2 : 2% by volume, H 2 O: 10% by volume, O 2 : 6% by volume, and the rest can be nitrogen. After aeration of the sample gas, the carbon-containing powder is heated to 400 ° C. under a nitrogen stream, and the generated SO 2 is collected and quantified, so that the adsorption capacity of SO 2 by the carbon-containing powder (unit: mg-SO 2). / G-carbon-containing powder).
(3)脱硝能の測定方法
分析用の反応槽内に炭素含有粉(試料)を5~50ml入れ、反応槽温度150℃、SV500h-1で反応槽内に、試料ガスを10時間通気する。試料ガスの組成は、NO:200ppm、NH3:200ppm、O2:6体積%、H2O:10体積%、残りを窒素とすることができる。試料ガスの通気後、反応槽から排出したガス中のNO濃度とO2濃度を測定し、定常状態におけるNO濃度の低下率を計算することにより、炭素含有粉による脱硝率(体積%)を求めることができる。 (3) Measuring method of denitration ability 5-50 ml of carbon-containing powder (sample) is put in a reaction tank for analysis, and sample gas is aerated in the reaction tank at a reaction tank temperature of 150 ° C. and SV500 h −1 for 10 hours. The composition of the sample gas can be NO: 200 ppm, NH 3 : 200 ppm, O 2 : 6% by volume, H 2 O: 10% by volume, and the rest can be nitrogen. After venting the sample gas, the NO concentration and O 2 concentration in the gas discharged from the reaction tank are measured, and the NO concentration rate (volume%) due to the carbon-containing powder is obtained by calculating the rate of decrease in the NO concentration in the steady state. be able to.
分析用の反応槽内に炭素含有粉(試料)を5~50ml入れ、反応槽温度150℃、SV500h-1で反応槽内に、試料ガスを10時間通気する。試料ガスの組成は、NO:200ppm、NH3:200ppm、O2:6体積%、H2O:10体積%、残りを窒素とすることができる。試料ガスの通気後、反応槽から排出したガス中のNO濃度とO2濃度を測定し、定常状態におけるNO濃度の低下率を計算することにより、炭素含有粉による脱硝率(体積%)を求めることができる。 (3) Measuring method of denitration ability 5-50 ml of carbon-containing powder (sample) is put in a reaction tank for analysis, and sample gas is aerated in the reaction tank at a reaction tank temperature of 150 ° C. and SV500 h −1 for 10 hours. The composition of the sample gas can be NO: 200 ppm, NH 3 : 200 ppm, O 2 : 6% by volume, H 2 O: 10% by volume, and the rest can be nitrogen. After venting the sample gas, the NO concentration and O 2 concentration in the gas discharged from the reaction tank are measured, and the NO concentration rate (volume%) due to the carbon-containing powder is obtained by calculating the rate of decrease in the NO concentration in the steady state. be able to.
(4)炭素含有率及び窒素含有率の測定方法
JIS M8819に準拠し、本実施形態に係る炭素含有粉の炭素含有率及び窒素含有率を測定した。 (4) Measuring method of carbon content and nitrogen content Based on JIS M8819, the carbon content and nitrogen content of the carbon containing powder which concern on this embodiment were measured.
JIS M8819に準拠し、本実施形態に係る炭素含有粉の炭素含有率及び窒素含有率を測定した。 (4) Measuring method of carbon content and nitrogen content Based on JIS M8819, the carbon content and nitrogen content of the carbon containing powder which concern on this embodiment were measured.
(5)硫黄含有率の測定方法
JIS M8813に準拠し、本実施形態に係る炭素含有粉の硫黄含有率を測定した。 (5) Measuring method of sulfur content rate Based on JIS M8813, the sulfur content rate of the carbon containing powder which concerns on this embodiment was measured.
JIS M8813に準拠し、本実施形態に係る炭素含有粉の硫黄含有率を測定した。 (5) Measuring method of sulfur content rate Based on JIS M8813, the sulfur content rate of the carbon containing powder which concerns on this embodiment was measured.
(6)炭素含有粉中の酸化物粒子の粒子径の測定方法
本実施形態に係る炭素含有粉をるつぼに入れ、空気の存在下で、600℃で2時間加熱して、炭素成分を燃焼させる。これにより、残留物として、炭素含有粉中に含まれる介在粒子である粒状酸化物(略球状の酸化物粒子P1)を得ることができる。通常、600℃では、炭素を主体とする成分は燃えてしまうが、粒状酸化物は、溶融しないため、その形を変化させずに、粒状酸化物を回収することができる。次いで、レーザー回折式粒度分布測定装置を用い、粒状酸化物の粒度分布を測定することで、体積基準の50%粒子径(メジアン径 D50)を求めることができる。 (6) Measuring method of particle diameter of oxide particles in carbon-containing powder The carbon-containing powder according to this embodiment is put in a crucible and heated at 600 ° C. for 2 hours in the presence of air to burn carbon components. . Thereby, the granular oxide (substantially spherical oxide particle P1) which is the intervening particle | grains contained in carbon containing powder can be obtained as a residue. Usually, at 600 ° C., the component mainly composed of carbon burns, but since the granular oxide does not melt, the granular oxide can be recovered without changing its shape. Subsequently, the volume-based 50% particle diameter (median diameter D50) can be determined by measuring the particle size distribution of the granular oxide using a laser diffraction particle size distribution measuring apparatus.
本実施形態に係る炭素含有粉をるつぼに入れ、空気の存在下で、600℃で2時間加熱して、炭素成分を燃焼させる。これにより、残留物として、炭素含有粉中に含まれる介在粒子である粒状酸化物(略球状の酸化物粒子P1)を得ることができる。通常、600℃では、炭素を主体とする成分は燃えてしまうが、粒状酸化物は、溶融しないため、その形を変化させずに、粒状酸化物を回収することができる。次いで、レーザー回折式粒度分布測定装置を用い、粒状酸化物の粒度分布を測定することで、体積基準の50%粒子径(メジアン径 D50)を求めることができる。 (6) Measuring method of particle diameter of oxide particles in carbon-containing powder The carbon-containing powder according to this embodiment is put in a crucible and heated at 600 ° C. for 2 hours in the presence of air to burn carbon components. . Thereby, the granular oxide (substantially spherical oxide particle P1) which is the intervening particle | grains contained in carbon containing powder can be obtained as a residue. Usually, at 600 ° C., the component mainly composed of carbon burns, but since the granular oxide does not melt, the granular oxide can be recovered without changing its shape. Subsequently, the volume-based 50% particle diameter (median diameter D50) can be determined by measuring the particle size distribution of the granular oxide using a laser diffraction particle size distribution measuring apparatus.
(7)炭素含有粉中の酸化物粒子の円形度の測定方法
上記(6)で回収した酸化物粒子P1の円形度は、粒子画像分析装置を用いて、撮像した酸化物粒子の形状を解析することで求めることができる。例えば、酸化物粒子の試料に分散剤水溶液を加えて超音波で分散処理した懸濁液を用意する。フロー式粒子像分析装置を用いて、シースフロー方式により、上記懸濁液中の酸化物粒子を静止画像として撮像できる。円形度の平均値は、試料中で測定された所定数以上の酸化物粒子の円形度の平均であってよい。上記平均値の算出に用いる酸化物粒子の数は、例えば10000個以上であってよい。 (7) Method for measuring circularity of oxide particles in carbon-containing powder The circularity of the oxide particles P1 recovered in (6) above is analyzed using a particle image analyzer to analyze the shape of the captured oxide particles. You can ask for it. For example, a suspension is prepared by adding an aqueous dispersant solution to a sample of oxide particles and dispersing the mixture with ultrasonic waves. Using a flow particle image analyzer, oxide particles in the suspension can be captured as a still image by the sheath flow method. The average value of circularity may be the average circularity of a predetermined number or more of oxide particles measured in a sample. The number of oxide particles used for calculating the average value may be, for example, 10,000 or more.
上記(6)で回収した酸化物粒子P1の円形度は、粒子画像分析装置を用いて、撮像した酸化物粒子の形状を解析することで求めることができる。例えば、酸化物粒子の試料に分散剤水溶液を加えて超音波で分散処理した懸濁液を用意する。フロー式粒子像分析装置を用いて、シースフロー方式により、上記懸濁液中の酸化物粒子を静止画像として撮像できる。円形度の平均値は、試料中で測定された所定数以上の酸化物粒子の円形度の平均であってよい。上記平均値の算出に用いる酸化物粒子の数は、例えば10000個以上であってよい。 (7) Method for measuring circularity of oxide particles in carbon-containing powder The circularity of the oxide particles P1 recovered in (6) above is analyzed using a particle image analyzer to analyze the shape of the captured oxide particles. You can ask for it. For example, a suspension is prepared by adding an aqueous dispersant solution to a sample of oxide particles and dispersing the mixture with ultrasonic waves. Using a flow particle image analyzer, oxide particles in the suspension can be captured as a still image by the sheath flow method. The average value of circularity may be the average circularity of a predetermined number or more of oxide particles measured in a sample. The number of oxide particles used for calculating the average value may be, for example, 10,000 or more.
(8)酸化物粒子中のSiO2成分及びAl2O3成分の含有率の測定方法
上記(6)で回収した略球状の酸化物粒子P1中のSiO2成分の含有率[質量%]、及び略球状の酸化物粒子中のAl2O3成分の含有率[質量%]は、蛍光X線分析法により測定可能である。 (8) the content of the SiO 2 component of substantially oxide particles P1 spherical recovered by the measuring method described above for the content of SiO 2 component and Al 2 O 3 component in the oxide particles (6) [wt%], And the content [mass%] of the Al 2 O 3 component in the substantially spherical oxide particles can be measured by fluorescent X-ray analysis.
上記(6)で回収した略球状の酸化物粒子P1中のSiO2成分の含有率[質量%]、及び略球状の酸化物粒子中のAl2O3成分の含有率[質量%]は、蛍光X線分析法により測定可能である。 (8) the content of the SiO 2 component of substantially oxide particles P1 spherical recovered by the measuring method described above for the content of SiO 2 component and Al 2 O 3 component in the oxide particles (6) [wt%], And the content [mass%] of the Al 2 O 3 component in the substantially spherical oxide particles can be measured by fluorescent X-ray analysis.
SiO2の含有率は、ガラスビード法による蛍光X線分析装置(XRF)により定量分析が可能である。具体的には、SiO2の含有率が既知である測定サンプルを、含有率を変えて複数準備して、蛍光X線分析装置により、準備した測定サンプルのSi由来の蛍光X線強度を測定する。得られたSi由来の蛍光X線強度と、SiO2の含有率とを用いて、SiO2の含有率と蛍光X線強度との間の関係を示す検量線を予め作成しておく。その後、着目するSiO2の含有率が未知の試料について、蛍光X線分析装置によりSi由来の蛍光X線強度を測定し、得られた蛍光X線強度と、検量線とを用いて、SiO2の含有率を特定することができる。これにより、上記の酸化物粒子P1中のSiO2成分の含有率を求めることができる。
The content of SiO 2 can be quantitatively analyzed by a fluorescent X-ray analyzer (XRF) using a glass bead method. Specifically, a plurality of measurement samples having a known SiO 2 content rate are prepared with different content rates, and the X-ray fluorescence intensity derived from Si of the prepared measurement sample is measured by a fluorescent X-ray analyzer. . Using the obtained Si-derived fluorescent X-ray intensity and the SiO 2 content, a calibration curve showing the relationship between the SiO 2 content and the fluorescent X-ray intensity is prepared in advance. Thereafter, the X-ray fluorescence intensity derived from Si is measured with a fluorescent X-ray analyzer for the sample whose SiO 2 content of interest is unknown, and using the obtained fluorescent X-ray intensity and the calibration curve, SiO 2 The content of can be specified. This makes it possible to determine the content of the SiO 2 component of the oxide particles P1 described above.
また、Al2O3の含有率は、ガラスビード法による蛍光X線分析装置(XRF)により定量分析が可能である。具体的には、Al2O3の含有率が既知である測定サンプルを、含有率を変えて複数準備して、蛍光X線分析装置により、準備した測定サンプルのAl由来の蛍光X線強度を測定する。得られたAl由来の蛍光X線強度と、Al2O3の含有率とを用いて、Al2O3の含有率と蛍光X線強度との間の関係を示す検量線を予め作成しておく。その後、着目するAl2O3の含有率が未知の試料について、蛍光X線分析装置によりAl2O3の蛍光X線強度を測定し、得られた蛍光X線強度と、検量線とを用いて、Al2O3の含有率を特定することができる。これにより、上記の酸化物粒子P1中のAl2O3成分の含有率cAlを求めることができる。
The content of Al 2 O 3 can be quantitatively analyzed by a fluorescent X-ray analyzer (XRF) using a glass bead method. Specifically, a plurality of measurement samples having a known content ratio of Al 2 O 3 are prepared by changing the content ratio, and the fluorescence X-ray intensity derived from Al of the prepared measurement sample is measured by a fluorescent X-ray analyzer. taking measurement. Using the obtained Al-derived fluorescent X-ray intensity and the Al 2 O 3 content, a calibration curve indicating the relationship between the Al 2 O 3 content and the fluorescent X-ray intensity was prepared in advance. deep. Then, using content for the unknown sample of Al 2 O 3 interest, the fluorescent X-ray intensity of Al 2 O 3 measured by a fluorescent X-ray analyzer, and the fluorescent X-ray intensities obtained, the calibration curve Thus, the content of Al 2 O 3 can be specified. This makes it possible to determine the content c Al of Al 2 O 3 component of the oxide particles P1 described above.
上記のように得られた酸化物粒子P1中のSiO2成分の含有率cSi[質量%]、及び酸化物粒子P1中のAl2O3成分の含有率cAl[質量%]より、以下の式(1)を用いて、炭素含有粉中の酸化物粒子P1中のSiO2成分及びAl2O3成分の合計の含有率cT[質量%]を測定できる。
cT=cSi+cAl ・・・(1) From the content c Si [mass%] of the SiO 2 component in the oxide particles P1 obtained as described above and the content c Al [mass%] of the Al 2 O 3 component in the oxide particles P1, the following Using the formula (1), the total content c T [mass%] of the SiO 2 component and the Al 2 O 3 component in the oxide particles P1 in the carbon-containing powder can be measured.
c T = c Si + c Al (1)
cT=cSi+cAl ・・・(1) From the content c Si [mass%] of the SiO 2 component in the oxide particles P1 obtained as described above and the content c Al [mass%] of the Al 2 O 3 component in the oxide particles P1, the following Using the formula (1), the total content c T [mass%] of the SiO 2 component and the Al 2 O 3 component in the oxide particles P1 in the carbon-containing powder can be measured.
c T = c Si + c Al (1)
なお、上記(4)(5)(8)の含有率を測定する場合、複数の試料を用いて測定した複数の含有率の平均値を算出してもよいし、或いは、1つの試料のみを用いて含有率を測定してもよい。測定精度の観点からは、複数の試料を用いて含有率を求めることが好ましい。上記(6)の粒子径及び(7)の円形度についても同様である。
In addition, when measuring the content rate of said (4), (5), and (8), you may calculate the average value of several content rate measured using several samples, or only one sample is calculated. You may use and measure a content rate. From the viewpoint of measurement accuracy, it is preferable to obtain the content using a plurality of samples. The same applies to the particle diameter (6) and the circularity (7).
[2.3.炭素含有粉のN/C比の低下原理]
次に、図4を参照して、本実施形態に係る炭素含有粉の窒素含有率とN/C比が低い理由について説明する。図4は、本実施形態に係る炭素含有粉P0の製造方法の概要を示す工程図である。 [2.3. Principle of reduction in N / C ratio of carbon-containing powder]
Next, the reason why the nitrogen content and the N / C ratio of the carbon-containing powder according to the present embodiment are low will be described with reference to FIG. FIG. 4 is a process diagram showing an outline of the method for producing the carbon-containing powder P0 according to the present embodiment.
次に、図4を参照して、本実施形態に係る炭素含有粉の窒素含有率とN/C比が低い理由について説明する。図4は、本実施形態に係る炭素含有粉P0の製造方法の概要を示す工程図である。 [2.3. Principle of reduction in N / C ratio of carbon-containing powder]
Next, the reason why the nitrogen content and the N / C ratio of the carbon-containing powder according to the present embodiment are low will be described with reference to FIG. FIG. 4 is a process diagram showing an outline of the method for producing the carbon-containing powder P0 according to the present embodiment.
図4に示すように、本実施形態に係る製造方法では、例えば、火力発電所のボイラー4等で、瀝青炭又は亜瀝青炭等の燃料炭FCが燃焼され、この燃焼の結果、石炭灰であるフライアッシュFAが生成される(燃焼工程)。このフライアッシュFAは、分離回収装置5(詳細は後述する。)に導入されて、本実施形態に係る特殊な湿式分離方法により、SiO2成分、Al2O3成分等からなる酸化物粒子P1(灰分)と、未燃カーボン粒子P2(炭素成分)とに分離されて、回収される(分離回収工程)。従って、本実施形態に係る炭素含有粉P0は、ボイラー4における燃焼工程と、分離回収装置5における分離回収工程を経て製造される。ここで、本実施形態に係る炭素含有粉P0の窒素含有率が低い理由は、以下に説明する通り、ボイラー4における石炭の燃焼工程に起因していると考えられる。
As shown in FIG. 4, in the manufacturing method according to the present embodiment, for example, fuel coal FC such as bituminous coal or sub-bituminous coal is burned in a boiler 4 of a thermal power plant, and as a result of this combustion, fly ash that is coal ash is produced. Ash FA is generated (combustion process). This fly ash FA is introduced into a separation and recovery device 5 (details will be described later), and oxide particles P1 made of SiO 2 component, Al 2 O 3 component, etc. by a special wet separation method according to this embodiment. (Ash content) and unburned carbon particles P2 (carbon component) are separated and recovered (separation and recovery step). Therefore, the carbon-containing powder P0 according to the present embodiment is manufactured through the combustion process in the boiler 4 and the separation and recovery process in the separation and recovery device 5. Here, the reason why the nitrogen content of the carbon-containing powder P0 according to the present embodiment is low is considered to be due to the coal combustion process in the boiler 4 as described below.
一般にコークス炉での石炭の乾留工程では、各種の乾留ガスが発生する。非特許文献2によれば、石炭種にもよるが、乾留ガス中の窒素系ガス(HCN、NH3、N2)のうち、HCN、NH3の発生は、約300℃から開始し、800℃程度で終息する。これに対し、N2は、約600℃から発生を開始し、他の窒素系ガスの発生がほぼ終息する800℃以上の高温においても発生し続けることがわかっている。また、一般的に、乾留ガス中の炭素系ガス(CO、CH4、HCN)の発生は少ない。これらのことから、石炭の乾留時には、石炭のN/C比はコークス炉内での乾留温度の上昇とともに低下すること、が予測できる。
非特許文献2:藤部 康弘、外2名、“ガスリアルタイム測定とXPS測定による石炭乾留過程における窒素の分配挙動”、材料とプロセス、Vol.25 No.2、Page.ROMBUNNO.36、2012年9月1日 In general, various carbonization gases are generated in a coal carbonization process in a coke oven. According to Non-Patent Document 2, although depending on the coal type, of the nitrogen-based gas in carbonization gas (HCN, NH 3, N 2), HCN, the generation of NH 3 begins at about 300 ° C., 800 End at around ℃. On the other hand, it has been found that N 2 starts to be generated at about 600 ° C. and continues to be generated even at a high temperature of 800 ° C. or higher at which generation of other nitrogen-based gases almost ends. In general, carbon-based gas (CO, CH 4 , HCN) is hardly generated in the dry distillation gas. From these facts, it can be predicted that during the dry distillation of coal, the N / C ratio of the coal decreases with an increase in the dry distillation temperature in the coke oven.
Non-Patent Document 2: Yasuhiro Fujibe and 2 others, “Partition behavior of nitrogen in coal retorting process by real-time gas measurement and XPS measurement”, Materials and Processes, Vol. 25 No. 2, Page. ROMBUNNO. 36, September 1, 2012
非特許文献2:藤部 康弘、外2名、“ガスリアルタイム測定とXPS測定による石炭乾留過程における窒素の分配挙動”、材料とプロセス、Vol.25 No.2、Page.ROMBUNNO.36、2012年9月1日 In general, various carbonization gases are generated in a coal carbonization process in a coke oven. According to Non-Patent Document 2, although depending on the coal type, of the nitrogen-based gas in carbonization gas (HCN, NH 3, N 2), HCN, the generation of NH 3 begins at about 300 ° C., 800 End at around ℃. On the other hand, it has been found that N 2 starts to be generated at about 600 ° C. and continues to be generated even at a high temperature of 800 ° C. or higher at which generation of other nitrogen-based gases almost ends. In general, carbon-based gas (CO, CH 4 , HCN) is hardly generated in the dry distillation gas. From these facts, it can be predicted that during the dry distillation of coal, the N / C ratio of the coal decreases with an increase in the dry distillation temperature in the coke oven.
Non-Patent Document 2: Yasuhiro Fujibe and 2 others, “Partition behavior of nitrogen in coal retorting process by real-time gas measurement and XPS measurement”, Materials and Processes, Vol. 25 No. 2, Page. ROMBUNNO. 36, September 1, 2012
一方、本実施形態に係る製造方法の燃焼工程において、発電所のボイラー4内の燃焼温度は、約1300~1500℃であり、かつ、ボイラー4内における石炭粉の滞留時間は、数秒程度であり、上記コークス炉における石炭粉の滞留時間と比べて非常に短く、かつ、ボイラー4内の石炭粉は、乾留状態ではなく燃焼状態になる。ボイラー4内には酸素濃度分布があり、石炭粉の表面近くでは、酸素濃度は特に低く、部分的に乾留状態に近い状態になると考えられる。このため、上記石炭の乾留工程と同様に、ボイラー4内の燃焼工程でも、燃焼温度が800℃以上の高温条件下では、粒子径が数mm程度の石炭粉の表層部分だけが乾留され、当該表層部分に含まれる窒素化合物が分解されてガス化するため、石炭粉の窒素成分が減少していると考えられる。従って、燃焼工程後のフライアッシュFA中の未燃カーボン粒子P2の窒素含有率が低下するため、当該未燃カーボン粒子を濃縮して回収された炭素含有粉P0のN/C比も低下すると考えられる。また、ボイラー4内の燃焼温度が上昇するに従い、炭素含有粉P0のN/C比は低下すると考えられる。
On the other hand, in the combustion process of the manufacturing method according to the present embodiment, the combustion temperature in the boiler 4 of the power plant is about 1300 to 1500 ° C., and the residence time of the coal powder in the boiler 4 is about several seconds. The residence time of the coal powder in the coke oven is very short, and the coal powder in the boiler 4 is in a combustion state instead of a dry distillation state. There is an oxygen concentration distribution in the boiler 4, and the oxygen concentration is particularly low near the surface of the coal powder, which is considered to be partially close to the dry distillation state. For this reason, in the combustion process in the boiler 4 as well, the surface part of the coal powder having a particle diameter of about several millimeters is carbonized under the high temperature condition of the combustion temperature of 800 ° C. It is considered that the nitrogen component of the coal powder is reduced because the nitrogen compound contained in the surface layer is decomposed and gasified. Therefore, since the nitrogen content of the unburned carbon particles P2 in the fly ash FA after the combustion process is lowered, it is considered that the N / C ratio of the carbon-containing powder P0 recovered by concentrating the unburned carbon particles is also lowered. It is done. Further, it is considered that the N / C ratio of the carbon-containing powder P0 decreases as the combustion temperature in the boiler 4 increases.
[2.4.炭素含有粉中の介在粒子の特徴]
次に、図1~図3を参照して、本実施形態に係る炭素含有粉に介在粒子として含まれる略球状の酸化物粒子P1に関する特徴について、より詳細に説明する。 [2.4. Characteristics of intervening particles in carbon-containing powder]
Next, characteristics of the substantially spherical oxide particles P1 included as intervening particles in the carbon-containing powder according to the present embodiment will be described in more detail with reference to FIGS.
次に、図1~図3を参照して、本実施形態に係る炭素含有粉に介在粒子として含まれる略球状の酸化物粒子P1に関する特徴について、より詳細に説明する。 [2.4. Characteristics of intervening particles in carbon-containing powder]
Next, characteristics of the substantially spherical oxide particles P1 included as intervening particles in the carbon-containing powder according to the present embodiment will be described in more detail with reference to FIGS.
図1に示すように、湿式分離処理前のフライアッシュFAは、未燃カーボン粒子P2よりも、略球状の酸化物粒子P1を多く含有しており、未燃カーボン粒子P2の細孔P20中に酸化物粒子P1が入り込み、かつ、未燃カーボン粒子P2の表面を酸化物粒子P1が覆っている。このため、従来では、未燃カーボン粒子P2単独の特性は不明であった。
As shown in FIG. 1, the fly ash FA before the wet separation treatment contains more spherical oxide particles P1 than the unburned carbon particles P2, and is contained in the pores P20 of the unburned carbon particles P2. Oxide particle P1 enters and oxide particle P1 covers the surface of unburned carbon particle P2. For this reason, conventionally, the characteristics of the unburned carbon particles P2 alone were unknown.
そこで、後述する本発明の第1の実施形態に係る製造方法では、粉砕処理を伴わない、水と疎水性液体を用いた湿式分離処理(後述の図5を参照。)により、未燃カーボン粒子P2と酸化物粒子P1とを分離する。これにより、図2に示すように、未燃カーボン粒子P2の表面に付着している酸化物粒子P1は除去されるが、未燃カーボン粒子P2の細孔P20中に進入している酸化物粒子P1を除去することは困難である。この理由は、上記の湿式分離処理では、水又は疎水性液体のうちいずれか一方若しくは双方が未燃カーボン粒子P2の細孔P20の内部まで入り込むことができないため、当該細孔P20から酸化物粒子P1を排出することが困難であるからと考えられる。
Therefore, in the manufacturing method according to the first embodiment of the present invention, which will be described later, unburned carbon particles are obtained by a wet separation process using water and a hydrophobic liquid (see FIG. 5 described later) that is not accompanied by a pulverization process. P2 and oxide particles P1 are separated. Thereby, as shown in FIG. 2, the oxide particles P1 adhering to the surface of the unburned carbon particles P2 are removed, but the oxide particles entering the pores P20 of the unburned carbon particles P2. It is difficult to remove P1. This is because, in the above-described wet separation process, either one or both of water and hydrophobic liquid cannot enter the pores P20 of the unburned carbon particles P2. It is thought that it is difficult to discharge P1.
ここで、かかる未燃カーボン粒子P2を含む炭素含有粉を、SO2吸着材として利用する場合を考える。酸化物粒子P1により閉塞された未燃カーボン粒子P2の細孔P20は、炭素含有粉の比表面積にはカウントされる。しかし、未燃カーボン粒子P2の細孔P20中に酸化物粒子P1が保持されているため、SO2等を含有する排ガス(常圧)のほとんどは、細孔P20の深部まで進入することができない。このため、SO2の吸着面として未燃カーボン粒子P2の細孔P20を有効に活用できておらず、SO2吸着材としての性能に改善の余地がある。
Here, the carbon-containing powder containing such unburned carbon particles P2, consider the case of using as SO 2 adsorbent. The pores P20 of the unburned carbon particles P2 clogged with the oxide particles P1 are counted as the specific surface area of the carbon-containing powder. However, since the oxide particles P1 are held in the pores P20 of the unburned carbon particles P2, most of the exhaust gas (normal pressure) containing SO 2 or the like cannot enter the deep part of the pores P20. . Therefore, not be effectively utilized pores P20 of unburned carbon particles P2 as an adsorption surface of the SO 2, there is room for improvement in performance as SO 2 adsorbent.
そこで、後述する本発明の第2の実施形態に係る製造方法では、未燃カーボン粒子P2の粉砕処理を伴う、湿式分離処理(後述の図7~図10を参照。)を行う。かかる粉砕処理により、図3に示すように、もろい多孔質の未燃カーボン粒子P2は容易に粉砕され、複数の細孔P20どうしが破断面P21でつながるため、未燃カーボン粒子P2が微細化されやすい。未燃カーボン粒子P2が粉砕されれば、細孔P20内の略球状の酸化物粒子P1は、水又は疎水性液体のうちいずれか一方若しくは双方と容易に接触することができ、多くの酸化物粒子P1を細孔P20から排出させ、未燃カーボン粒子P2から分離することができる。これにより、酸化物粒子P1が分離された、未燃カーボン粒子P2を主体とする炭素含有粉が得られる。この炭素含有粉においては、炭素含有率が増加するとともに、SO2の吸着面となる炭素成分の表面積も増加する。従って、当該炭素含有粉によるSO2含有ガスの処理能力が上昇し、SO2吸着材としての性能が向上する。
Therefore, in the manufacturing method according to the second embodiment of the present invention, which will be described later, a wet separation process (see FIGS. 7 to 10 described later) is performed that involves a pulverization process of the unburned carbon particles P2. By this pulverization treatment, as shown in FIG. 3, the fragile porous unburned carbon particles P2 are easily crushed, and the plurality of pores P20 are connected at the fracture surface P21, so that the unburned carbon particles P2 are refined. Cheap. If the unburned carbon particles P2 are pulverized, the substantially spherical oxide particles P1 in the pores P20 can easily come into contact with either or both of water and a hydrophobic liquid, and many oxides The particles P1 can be discharged from the pores P20 and separated from the unburned carbon particles P2. Thereby, a carbon-containing powder mainly composed of unburned carbon particles P2 from which the oxide particles P1 are separated is obtained. In this carbon-containing powder, the carbon content increases, and the surface area of the carbon component serving as the SO 2 adsorption surface also increases. Therefore, the processing capacity of the SO 2 -containing gas by the carbon-containing powder is increased, and the performance as the SO 2 adsorbent is improved.
[3.炭素含有粉の製造方法]
次に、本実施形態に係る炭素含有粉の製造方法について詳細に説明する。 [3. Method for producing carbon-containing powder]
Next, the manufacturing method of the carbon containing powder which concerns on this embodiment is demonstrated in detail.
次に、本実施形態に係る炭素含有粉の製造方法について詳細に説明する。 [3. Method for producing carbon-containing powder]
Next, the manufacturing method of the carbon containing powder which concerns on this embodiment is demonstrated in detail.
[3.1.炭素含有粉の製造方法の概要]
まず、図4を参照して、本実施形態に係る炭素含有粉の製造方法の概要を説明する。 [3.1. Outline of production method of carbon-containing powder]
First, with reference to FIG. 4, the outline | summary of the manufacturing method of the carbon containing powder which concerns on this embodiment is demonstrated.
まず、図4を参照して、本実施形態に係る炭素含有粉の製造方法の概要を説明する。 [3.1. Outline of production method of carbon-containing powder]
First, with reference to FIG. 4, the outline | summary of the manufacturing method of the carbon containing powder which concerns on this embodiment is demonstrated.
図4に示すように、本実施形態に係る炭素含有粉の製造方法は、燃焼工程(S0)と、分離回収工程(S1)とを含む。燃焼工程(S0)では、火力発電所等のボイラー4により、燃料炭FCを燃焼させて、石炭灰であるフライアッシュFAを生成する。次いで、分離回収工程(S1)では、分離回収装置5により、フライアッシュFAから酸化物粒子P1と未燃カーボン粒子P2を分離して、それぞれ回収する。
As shown in FIG. 4, the carbon-containing powder production method according to the present embodiment includes a combustion step (S0) and a separation and recovery step (S1). In the combustion step (S0), the fuel coal FC is burned by a boiler 4 such as a thermal power plant to generate fly ash FA that is coal ash. Next, in the separation and recovery step (S1), the separation and recovery device 5 separates the oxide particles P1 and the unburned carbon particles P2 from the fly ash FA and recovers them.
[3.2.比重分離方法]
続いて、本実施形態に係る分離回収工程(S1)において、フライアッシュFAを酸化物粒子P1と未燃カーボン粒子P2とに分離する方法についてより詳細に説明する。 [3.2. Specific gravity separation method]
Next, a method for separating fly ash FA into oxide particles P1 and unburned carbon particles P2 in the separation and recovery step (S1) according to the present embodiment will be described in more detail.
続いて、本実施形態に係る分離回収工程(S1)において、フライアッシュFAを酸化物粒子P1と未燃カーボン粒子P2とに分離する方法についてより詳細に説明する。 [3.2. Specific gravity separation method]
Next, a method for separating fly ash FA into oxide particles P1 and unburned carbon particles P2 in the separation and recovery step (S1) according to the present embodiment will be described in more detail.
本実施形態に係る分離回収工程では、フライアッシュFAに由来し、酸化物粒子P1と未燃カーボン粒子P2とが混在する混合物を、未燃カーボン粒子P2を主体とする炭素含有粉P0と、酸化物粒子P1とに湿式分離する。
In the separation and recovery process according to the present embodiment, a mixture containing oxide particles P1 and unburned carbon particles P2 derived from fly ash FA is mixed with carbon-containing powder P0 mainly composed of unburned carbon particles P2 and oxidized. Wet-separate into product particles P1.
この分離方法では、親水性粒子である酸化物粒子P1の抽出剤として水を使用するとともに、疎水性粒子である未燃カーボン粒子P2の抽出剤として、例えば、水より比重が大きい疎水性液体を使用する。そして、当該水と疎水性液体を、処理対象の混合物であるフライアッシュ(固形分)FAに混合して撹拌し、混合物が分散した混合液(第1スラリー)を生成する(混合工程)。次いで、分離装置(例えば、沈殿槽、静置槽等のセトラー)内で当該混合液を静置することで、水と疎水性液体の比重差を利用して、上記混合液を上側の水相と、下側の疎水性液体相との2相に分離しつつ、酸化物粒子P1(親水性粒子)を水相に移動させ、未燃カーボン粒子P2(疎水性粒子)を疎水性液体相に移動させる(比重分離工程)。さらに、分離された水相(第2スラリー)から、酸化物粒子P1を分離して回収するとともに(第1回収工程)、上記分離工程で分離された疎水性液体相(第3スラリー)から、未燃カーボン粒子P2を分離して回収する(第2回収工程)。これによって、酸化物粒子P1と未燃カーボン粒子P2を迅速かつ効率的に分離でき、含有率の高い酸化物粒子P1と未燃カーボン粒子P2をそれぞれ回収して再利用することができる。
In this separation method, water is used as an extractant for the oxide particles P1 which are hydrophilic particles, and a hydrophobic liquid having a specific gravity greater than that of water is used as an extractant for the unburned carbon particles P2 which are hydrophobic particles. use. And the said water and hydrophobic liquid are mixed and stirred in the fly ash (solid content) FA which is a process target mixture, and the liquid mixture (1st slurry) in which the mixture was disperse | distributed is produced | generated (mixing process). Next, the mixed liquid is allowed to stand in a separation apparatus (for example, a settler such as a precipitation tank or a stationary tank), and the above mixed liquid is removed from the upper aqueous phase by utilizing the specific gravity difference between water and the hydrophobic liquid. And the lower hydrophobic liquid phase, the oxide particles P1 (hydrophilic particles) are moved to the aqueous phase, and the unburned carbon particles P2 (hydrophobic particles) are changed to the hydrophobic liquid phase. Move (specific gravity separation step). Furthermore, from the separated aqueous phase (second slurry), the oxide particles P1 are separated and recovered (first recovery step), and from the hydrophobic liquid phase (third slurry) separated in the separation step, Unburned carbon particles P2 are separated and recovered (second recovery step). As a result, the oxide particles P1 and the unburned carbon particles P2 can be quickly and efficiently separated, and the oxide particles P1 and the unburned carbon particles P2 having a high content can be recovered and reused.
ここで、疎水性液体は、疎水性を有する液体、即ち、水に対する親和性が低い(言い換えると水に溶解し難い、若しくは水と混ざり難い)性質を有する液体である。疎水性液体は、20℃の水に対する溶解度が0g/L以上、5.0g/L以下の液体であってよい。なお、本明細書における疎水性とは、親油性を含む性質である。疎水性液体は、疎水性を有する有機溶剤(以下、「疎水性溶剤」という。)、又は、シリコーンオイル等の各種の油であってよい。疎水性溶剤としては、例えば、フッ素系、臭素系若しくは塩素系の有機溶剤等を使用できる。かかる疎水性液体は、水に対する親和性が低いので、疎水性液体と水を混合及び撹拌した混合液を静置すると、水を主体とする水相と、疎水性液体(例えば疎水性溶剤)を主体とする疎水性液体相(例えば疎水性溶剤相)の2相に分離される。
Here, the hydrophobic liquid is a liquid having hydrophobicity, that is, a liquid having a property of low affinity for water (in other words, hardly dissolved in water or mixed with water). The hydrophobic liquid may be a liquid having a solubility in water at 20 ° C. of 0 g / L or more and 5.0 g / L or less. In addition, hydrophobicity in this specification is a property including lipophilicity. The hydrophobic liquid may be an organic solvent having hydrophobicity (hereinafter referred to as “hydrophobic solvent”) or various oils such as silicone oil. As the hydrophobic solvent, for example, a fluorine-based, bromine-based or chlorine-based organic solvent can be used. Since such a hydrophobic liquid has a low affinity for water, when the mixed liquid obtained by mixing and stirring the hydrophobic liquid and water is allowed to stand, an aqueous phase mainly composed of water and a hydrophobic liquid (for example, a hydrophobic solvent) are separated. It is separated into two phases of a hydrophobic liquid phase (for example, a hydrophobic solvent phase) as a main component.
表2は、本実施形態に係る分離方法で使用される疎水性液体の例を示す。表2に例示する疎水性液体はいずれも、その比重が1超であり、水に対する溶解度が5.0g/L以下であり、疎水性を有する。
Table 2 shows examples of hydrophobic liquids used in the separation method according to this embodiment. All of the hydrophobic liquids exemplified in Table 2 have a specific gravity of more than 1, a solubility in water of 5.0 g / L or less, and are hydrophobic.
また、疎水性液体の比重は、1.05超であることが好ましい。これにより、水と疎水性液体の比重差により、混合液の静置後、例えば1~30秒程度の短時間で迅速に、水相と疎水性液体相に分離することができる。
The specific gravity of the hydrophobic liquid is preferably more than 1.05. Thereby, due to the difference in specific gravity between water and the hydrophobic liquid, it is possible to quickly separate into the aqueous phase and the hydrophobic liquid phase in a short time of, for example, about 1 to 30 seconds after the liquid mixture is allowed to stand.
親水性粒子は、水に対する親和性を有する粒子であり、上記疎水性液体よりも水に混ざり易い性質を有する。フライアッシュFAに含まれる酸化物粒子P1は、親水性粒子である。一方、疎水性粒子は、上記疎水性液体に対する親和性を有する粒子であり、水よりも疎水性液体に混ざり易い性質を有する。フライアッシュFAに含まれる未燃カーボン粒子P2は、疎水性粒子である。従って、水と疎水性液体の混合液中では、親水性粒子(酸化物粒子P1)は疎水性液体相から水相に移動して、主に水相中に分散して存在するようになる。一方、疎水性粒子(未燃カーボン粒子P2)は水相から疎水性液体相に移動して、主に疎水性液体相中に分散して存在するようになる。
Hydrophilic particles are particles having an affinity for water and have a property of being more easily mixed with water than the hydrophobic liquid. The oxide particles P1 contained in the fly ash FA are hydrophilic particles. On the other hand, the hydrophobic particles are particles having an affinity for the hydrophobic liquid and have a property of being easily mixed in the hydrophobic liquid rather than water. The unburned carbon particles P2 contained in the fly ash FA are hydrophobic particles. Accordingly, in the mixed liquid of water and the hydrophobic liquid, the hydrophilic particles (oxide particles P1) move from the hydrophobic liquid phase to the aqueous phase and are mainly dispersed in the aqueous phase. On the other hand, the hydrophobic particles (unburned carbon particles P2) move from the aqueous phase to the hydrophobic liquid phase, and are mainly dispersed in the hydrophobic liquid phase.
また、親水性粒子である酸化物粒子P1の比重は、例えば、2.4~2.6である。疎水性粒子である未燃カーボン粒子P2の比重は、例えば1.3~1.5である。このように親水性粒子の比重よりも疎水性粒子の比重の方が小さい場合であっても、本実施形態に係る分離方法によれば、親水性粒子を上相の水相に浮上させ、疎水性粒子を下相の疎水性液体相に沈降させて、両粒子を迅速かつ効率的に湿式分離することができる。なお、酸化物粒子P1の比重が未燃カーボン粒子P2の比重より小さくても、上記のように水及び疎水性液体を用いた湿式分離により、酸化物粒子P1と未燃カーボン粒子P2を分離することは可能である。なお、本明細書において、粒子の比重とは、粒子自体の比重(真比重)であって、粒子の嵩比重ではない。
The specific gravity of the oxide particles P1 that are hydrophilic particles is, for example, 2.4 to 2.6. The specific gravity of the unburned carbon particles P2 that are hydrophobic particles is, for example, 1.3 to 1.5. Thus, even when the specific gravity of the hydrophobic particles is smaller than the specific gravity of the hydrophilic particles, according to the separation method according to the present embodiment, the hydrophilic particles are floated on the water phase of the upper phase, The particles can be settled in the lower hydrophobic liquid phase, and both particles can be wet-separated quickly and efficiently. Even if the specific gravity of the oxide particles P1 is smaller than the specific gravity of the unburned carbon particles P2, the oxide particles P1 and the unburned carbon particles P2 are separated by wet separation using water and a hydrophobic liquid as described above. It is possible. In the present specification, the specific gravity of the particle is the specific gravity (true specific gravity) of the particle itself and not the bulk specific gravity of the particle.
[3.3.炭素含有粉の分離回収方法]
次に、図5を参照して、本実施形態に係る炭素含有粉の製造方法における分離回収方法について詳細に説明する。なお、以下の説明では、疎水性液体として疎水性溶剤を用いる例について説明する。 [3.3. Method for separating and collecting carbon-containing powder]
Next, with reference to FIG. 5, the separation and recovery method in the carbon-containing powder manufacturing method according to the present embodiment will be described in detail. In the following description, an example in which a hydrophobic solvent is used as the hydrophobic liquid will be described.
次に、図5を参照して、本実施形態に係る炭素含有粉の製造方法における分離回収方法について詳細に説明する。なお、以下の説明では、疎水性液体として疎水性溶剤を用いる例について説明する。 [3.3. Method for separating and collecting carbon-containing powder]
Next, with reference to FIG. 5, the separation and recovery method in the carbon-containing powder manufacturing method according to the present embodiment will be described in detail. In the following description, an example in which a hydrophobic solvent is used as the hydrophobic liquid will be described.
図5に示すように、分離回収工程(S1)は、比重分離工程(S2)と、回収工程(S4)とを含む。比重分離工程(S2)は、粗分離工程(S21)及び水洗浄工程(S22)を含み、回収工程(S4)は、固液分離工程(S41)及び乾燥工程(S42)を含む。
As shown in FIG. 5, the separation and recovery step (S1) includes a specific gravity separation step (S2) and a recovery step (S4). The specific gravity separation step (S2) includes a rough separation step (S21) and a water washing step (S22), and the recovery step (S4) includes a solid-liquid separation step (S41) and a drying step (S42).
比重分離工程(S2)の粗分離工程(S21)では、フライアッシュFAと水L1と疎水性溶剤L2とを混合する。当該混合液を静置することにより、固形分として未燃カーボン粒子P2(言い換えると炭素粒子)を主に含む疎水性溶剤相ph2と、酸化物粒子P1を主に含む水相ph1とに比重分離する。この粗分離工程(S21)により、フライアッシュFA中の未燃カーボン粒子P2と酸化物粒子P1を粗く分離することができる。これにより、疎水性溶剤相ph2中の固形分中の未燃カーボン粒子P2の含有率(言い換えると炭素含有率)を増加させることができる。
In the coarse separation step (S21) of the specific gravity separation step (S2), fly ash FA, water L1, and hydrophobic solvent L2 are mixed. By allowing the mixture to stand, specific gravity separation into a hydrophobic solvent phase ph2 mainly containing unburned carbon particles P2 (in other words, carbon particles) as a solid content and an aqueous phase ph1 mainly containing oxide particles P1. To do. By this rough separation step (S21), the unburned carbon particles P2 and the oxide particles P1 in the fly ash FA can be roughly separated. Thereby, the content rate (in other words, carbon content rate) of the unburned carbon particle P2 in the solid content in the hydrophobic solvent phase ph2 can be increased.
次いで、水洗浄工程(S22)では、上記粗分離工程(S21)で分離された疎水性溶剤相ph2に対して水L1を加えて混合する。当該混合液を静置することにより、固形分として未燃カーボン粒子P2が濃縮された疎水性溶剤相ph2と、残存した酸化物粒子P1を主に含む水相ph1とに比重分離する。この水洗浄工程(S22)により、未燃カーボン粒子P2を含む疎水性溶剤相ph2を水L1で洗浄し、粗分離工程(S21)で残存した酸化物粒子P1を未燃カーボン粒子P2から分離・除去できる。従って、疎水性溶剤相ph2に含まれる未燃カーボン粒子P2を濃縮させ、疎水性溶剤相ph2中の固形分中の未燃カーボン粒子P2の含有率(炭素含有率)をさらに増加させることができる。
Next, in the water washing step (S22), water L1 is added to and mixed with the hydrophobic solvent phase ph2 separated in the coarse separation step (S21). By allowing the mixed liquid to stand, specific gravity separation is performed on the hydrophobic solvent phase ph2 in which the unburned carbon particles P2 are concentrated as a solid content and the aqueous phase ph1 mainly containing the remaining oxide particles P1. In this water washing step (S22), the hydrophobic solvent phase ph2 containing the unburned carbon particles P2 is washed with water L1, and the oxide particles P1 remaining in the rough separation step (S21) are separated from the unburned carbon particles P2. Can be removed. Therefore, the unburned carbon particles P2 contained in the hydrophobic solvent phase ph2 can be concentrated, and the content (carbon content) of the unburned carbon particles P2 in the solid content in the hydrophobic solvent phase ph2 can be further increased. .
かかる水洗浄工程(S22)は、1回だけ行われてもよいが、複数回(例えば2~4回)行うことにより、疎水性溶剤相ph2中の固形物中の未燃カーボン粒子P2の含有率(言い換えると炭素含有率)をより一層増加させることができる。なお、比重分離工程(S2)において、水洗浄工程(S22)は必須ではなく、上記粗分離工程(S21)だけを行ってもよい。この場合でも、未燃カーボン粒子P2と酸化物粒子P1をある程度分離でき、未燃カーボン粒子P2の含有率の高い疎水性溶剤相ph2を得ることは可能である。
The water washing step (S22) may be performed only once, but by performing a plurality of times (for example, 2 to 4 times), the inclusion of unburned carbon particles P2 in the solid matter in the hydrophobic solvent phase ph2 The rate (in other words, the carbon content) can be further increased. In the specific gravity separation step (S2), the water washing step (S22) is not essential, and only the rough separation step (S21) may be performed. Even in this case, the unburned carbon particles P2 and the oxide particles P1 can be separated to some extent, and it is possible to obtain a hydrophobic solvent phase ph2 having a high content of unburned carbon particles P2.
次いで、回収工程(S4)の固液分離工程(S41)では、ろ過又は遠心分離などの固液分離処理により、上記比重分離工程(S2)で分離された疎水性溶剤相ph2を、液体分の疎水性溶剤L2と、固形分の粒子(主に未燃カーボン粒子P2と残存した酸化物粒子P1)とに分離し、固形分の粒子から疎水性溶剤L2を除去する。これにより、未燃カーボン粒子P2等の固形分の粒子を主体とするケーキC2が回収される。
Next, in the solid-liquid separation step (S41) of the recovery step (S4), the hydrophobic solvent phase ph2 separated in the specific gravity separation step (S2) is separated from the liquid component by solid-liquid separation treatment such as filtration or centrifugation. The hydrophobic solvent L2 is separated into solid particles (mainly unburned carbon particles P2 and remaining oxide particles P1), and the hydrophobic solvent L2 is removed from the solid particles. As a result, the cake C2 mainly containing solid particles such as unburned carbon particles P2 is recovered.
その後、乾燥工程(S42)では、当該ケーキC2を加熱することにより、ケーキC2中に残存している疎水性溶剤L2を揮発させる。これにより、未燃カーボン粒子P2を主体とする炭素含有粉P0(炭素含有率:50質量%以上)が回収される。
Thereafter, in the drying step (S42), the hydrophobic solvent L2 remaining in the cake C2 is volatilized by heating the cake C2. Thereby, carbon-containing powder P0 (carbon content: 50% by mass or more) mainly containing unburned carbon particles P2 is recovered.
ここで、疎水性溶剤L2の沸点は、大気圧下で200℃未満であることが好ましく、100℃未満であることがさらに好ましい。これにより、上記乾燥工程(S42)で、未燃カーボン粒子P2を主体とするケーキC2を乾燥させて、疎水性溶剤L2を揮発、除去するときに、加熱源として安価な熱源(例えば、蒸気)を使用することができる。
Here, the boiling point of the hydrophobic solvent L2 is preferably less than 200 ° C. under atmospheric pressure, and more preferably less than 100 ° C. Thereby, in the said drying process (S42), when the cake C2 which mainly has the unburned carbon particle P2 is dried and the hydrophobic solvent L2 is volatilized and removed, an inexpensive heat source (for example, steam) is used as a heating source. Can be used.
以上のように、本実施形態に係る炭素含有粉の製造方法の分離回収工程によれば、フライアッシュFAから、未燃カーボン粒子P2を主体とする炭素含有粉P0を分離、回収して、炭素含有率が50質量%以上の炭素含有粉P0を得ることができる。
As described above, according to the separation and recovery step of the method for producing carbon-containing powder according to the present embodiment, carbon-containing powder P0 mainly composed of unburned carbon particles P2 is separated and recovered from fly ash FA, and carbon. A carbon-containing powder P0 having a content of 50% by mass or more can be obtained.
[4.分離回収装置の構成]
次に、図6を参照して、本実施形態に係る分離回収工程を実行する分離回収装置5の構成と動作について詳細に説明する。図6は、本実施形態に係る分離回収装置5を示す模式図である。なお、使用する疎水性溶剤L2の比重は、1.05超とする。 [4. Configuration of separation and recovery equipment]
Next, with reference to FIG. 6, the configuration and operation of the separation /recovery device 5 that performs the separation / recovery process according to the present embodiment will be described in detail. FIG. 6 is a schematic diagram showing the separation and recovery device 5 according to this embodiment. The specific gravity of the hydrophobic solvent L2 to be used is more than 1.05.
次に、図6を参照して、本実施形態に係る分離回収工程を実行する分離回収装置5の構成と動作について詳細に説明する。図6は、本実施形態に係る分離回収装置5を示す模式図である。なお、使用する疎水性溶剤L2の比重は、1.05超とする。 [4. Configuration of separation and recovery equipment]
Next, with reference to FIG. 6, the configuration and operation of the separation /
図6に示すように、本実施形態に係る分離回収装置5は、上記比重分離工程(S2)を実行する2組の混合装置(ミキサー51A、51B)及び分離装置(セトラー52A、52B)と、第1回収装置61と、上記回収工程(S4)を実行する第2回収装置62とを備える。
As shown in FIG. 6, the separation and recovery device 5 according to the present embodiment includes two sets of mixing devices ( mixers 51A and 51B) and separation devices ( settlers 52A and 52B) that perform the specific gravity separation step (S2). The 1st collection | recovery apparatus 61 and the 2nd collection | recovery apparatus 62 which performs the said collection process (S4) are provided.
(1)混合装置と分離装置による粗分離工程(S21)
上記比重分離工程(S2)の粗分離工程(S21)では、水L1と疎水性溶剤L2とを混合した混合液にフライアッシュFAを混合して静置する。これにより、混合液を水相ph1と疎水性溶剤相ph2とに相分離させて、親水性の酸化物粒子P1を水相ph1へ移動させ、疎水性の未燃カーボン粒子P2を疎水性溶剤相ph2へ移動させることで、酸化物粒子P1と未燃カーボン粒子P2を粗分離する。この粗分離工程(S21)は、混合装置(ミキサー51A)による混合工程と、分離装置(セトラー52A)による比重分離工程を含む。 (1) Coarse separation step using a mixing device and a separation device (S21)
In the coarse separation step (S21) of the specific gravity separation step (S2), fly ash FA is mixed with a liquid mixture obtained by mixing water L1 and hydrophobic solvent L2, and allowed to stand. As a result, the mixed liquid is phase-separated into the aqueous phase ph1 and the hydrophobic solvent phase ph2, the hydrophilic oxide particles P1 are moved to the aqueous phase ph1, and the hydrophobic unburned carbon particles P2 are transferred to the hydrophobic solvent phase. By moving to ph2, the oxide particles P1 and the unburned carbon particles P2 are roughly separated. This rough separation step (S21) includes a mixing step by the mixing device (mixer 51A) and a specific gravity separation step by the separation device (settler 52A).
上記比重分離工程(S2)の粗分離工程(S21)では、水L1と疎水性溶剤L2とを混合した混合液にフライアッシュFAを混合して静置する。これにより、混合液を水相ph1と疎水性溶剤相ph2とに相分離させて、親水性の酸化物粒子P1を水相ph1へ移動させ、疎水性の未燃カーボン粒子P2を疎水性溶剤相ph2へ移動させることで、酸化物粒子P1と未燃カーボン粒子P2を粗分離する。この粗分離工程(S21)は、混合装置(ミキサー51A)による混合工程と、分離装置(セトラー52A)による比重分離工程を含む。 (1) Coarse separation step using a mixing device and a separation device (S21)
In the coarse separation step (S21) of the specific gravity separation step (S2), fly ash FA is mixed with a liquid mixture obtained by mixing water L1 and hydrophobic solvent L2, and allowed to stand. As a result, the mixed liquid is phase-separated into the aqueous phase ph1 and the hydrophobic solvent phase ph2, the hydrophilic oxide particles P1 are moved to the aqueous phase ph1, and the hydrophobic unburned carbon particles P2 are transferred to the hydrophobic solvent phase. By moving to ph2, the oxide particles P1 and the unburned carbon particles P2 are roughly separated. This rough separation step (S21) includes a mixing step by the mixing device (
混合工程では、酸化物粒子P1及び未燃カーボン粒子P2が混在したフライアッシュFAを、水L1及び疎水性溶剤L2に混合して、混合液を撹拌してスラリー化し、第1スラリーを生成する。この混合工程を実行する混合装置としては、例えば、混合液を撹拌する撹拌翼を備えた容器、ラインミキサー、又は内部で混合液を撹拌可能なポンプなどを使用することができる。
In the mixing step, fly ash FA in which oxide particles P1 and unburned carbon particles P2 are mixed is mixed with water L1 and hydrophobic solvent L2, and the mixed solution is stirred to form a first slurry. As a mixing apparatus for executing this mixing step, for example, a container equipped with a stirring blade for stirring the mixed solution, a line mixer, or a pump capable of stirring the mixed solution inside can be used.
図6の例のミキサー51Aは、モータ511Aと撹拌翼512Aを有する攪拌機である。このミキサー51Aは、後段のセトラー52Aに対して配管80Aを介して接続されている。ミキサー51Aの容器内部には、分離対象の混合物であるフライアッシュFAと、水L1と、水L1より比重が大きい疎水性溶剤L2とが投入される。ミキサー51Aは、モータ511Aにより撹拌翼512Aを回転させることにより、フライアッシュFAと水L1と疎水性溶剤L2とを混合して、第1スラリー(酸化物粒子P1と未燃カーボン粒子P2と水L1と疎水性溶剤L2の混合液)を生成する(混合工程)。
The mixer 51A in the example of FIG. 6 is a stirrer having a motor 511A and a stirring blade 512A. The mixer 51A is connected to a subsequent setter 52A via a pipe 80A. In the container of the mixer 51A, a fly ash FA that is a mixture to be separated, water L1, and a hydrophobic solvent L2 having a specific gravity greater than that of the water L1 are charged. The mixer 51A rotates the stirring blade 512A with the motor 511A, thereby mixing the fly ash FA, the water L1, and the hydrophobic solvent L2, and the first slurry (the oxide particles P1, the unburned carbon particles P2, and the water L1). And a mixed solution of the hydrophobic solvent L2) (mixing step).
セトラー52Aは、比重分離工程を実行する分離装置の一例である。セトラー52Aは、上記混合工程で生成された第1スラリーを静置することにより、水L1と疎水性溶剤L2の比重差を利用して、酸化物粒子P1を主として含む水相ph1と、未燃カーボン粒子P2を主として含む疎水性溶剤相ph2とに分離する。
The settler 52A is an example of a separation device that performs a specific gravity separation step. The settler 52A, by allowing the first slurry produced in the mixing step to stand, makes use of the specific gravity difference between the water L1 and the hydrophobic solvent L2, and the water phase ph1 mainly containing the oxide particles P1 and unburned Separated into a hydrophobic solvent phase ph2 mainly containing carbon particles P2.
セトラー52Aは、複数種類の液体の混合液を静置して、比重差を用いて該液体を分離する比重分離装置の一例であり、上記ミキサー51Aに対して配管80Aを介して接続されている。また、セトラー52Aは、後段の第1回収装置61に対して配管81Aを介して接続されている。当該配管81Aには、酸化物粒子P1を含む水相ph1(第2スラリー)を送出するためのポンプ71Aが設けられている。さらに、セトラー52Aは、後段のミキサー51Bに対して配管82Aを介して接続され、当該配管82Aには、未燃カーボン粒子P2を含む溶剤相ph2(第3スラリー)を送出するためのポンプ72Aが設けられている。
The settler 52A is an example of a specific gravity separation device that leaves a mixed liquid of a plurality of types of liquid and separates the liquid using a specific gravity difference, and is connected to the mixer 51A via a pipe 80A. . Further, the settler 52A is connected to the first recovery device 61 at the subsequent stage via a pipe 81A. The pipe 81A is provided with a pump 71A for sending out an aqueous phase ph1 (second slurry) containing the oxide particles P1. Further, the settler 52A is connected to the subsequent mixer 51B via a pipe 82A, and a pump 72A for sending the solvent phase ph2 (third slurry) containing unburned carbon particles P2 is connected to the pipe 82A. Is provided.
セトラー52Aは、ミキサー51Aから配管80Aを通じて導入された第1スラリーを、比重差を利用して、上相の水相ph1と、下相の疎水性溶剤相ph2(以下、「溶剤相ph2」と称する場合もある。)とに分離しながら、酸化物粒子P1を水相ph1に移動させ、未燃カーボン粒子P2を溶剤相ph2に移動させる。これにより、酸化物粒子P1と未燃カーボン粒子P2を分離する。その後、酸化物粒子P1を含む水相ph1(第2スラリー)は、セトラー52Aの上部から配管81Aを通じて第1回収装置61に排出される。一方、未燃カーボン粒子P2を含む溶剤相ph2(第3スラリー)は、セトラー52Aの下部から配管82Aを通じてミキサー51Bに排出される。この第3スラリーは、固形分として、未燃カーボン粒子P2を主に含むが、分離しきれなかった酸化物粒子P1も含んでいる。
The settler 52A uses the difference in specific gravity for the first slurry introduced from the mixer 51A through the pipe 80A, the upper phase aqueous phase ph1, and the lower phase hydrophobic solvent phase ph2 (hereinafter referred to as “solvent phase ph2”). The oxide particles P1 are moved to the aqueous phase ph1, and the unburned carbon particles P2 are moved to the solvent phase ph2. Thereby, the oxide particles P1 and the unburned carbon particles P2 are separated. Thereafter, the aqueous phase ph1 (second slurry) containing the oxide particles P1 is discharged from the upper part of the settler 52A to the first recovery device 61 through the pipe 81A. On the other hand, the solvent phase ph2 (third slurry) containing the unburned carbon particles P2 is discharged from the lower part of the settler 52A to the mixer 51B through the pipe 82A. This third slurry mainly includes unburned carbon particles P2 as solid content, but also includes oxide particles P1 that could not be separated.
(2)混合装置と分離装置による水洗浄工程(S22)
上記比重分離工程(S2)の水洗浄工程(S22)では、上記粗分離工程(S21)で回収された溶剤相ph2(第3スラリー)に水L1を加えて混合した後、静置する。これにより、混合液を水相ph1と疎水性溶剤相ph2とに相分離させて、上記第3スラリー中に残存していた酸化物粒子P1を水相ph1に移動させ、未燃カーボン粒子P2を溶剤相ph2に濃縮させる。この結果、溶剤相ph2に含まれる固形物中の未燃カーボン粒子P2の含有率を増加させることができる。 (2) Water washing step with mixing device and separation device (S22)
In the water washing step (S22) of the specific gravity separation step (S2), water L1 is added to and mixed with the solvent phase ph2 (third slurry) recovered in the rough separation step (S21), and then left to stand. As a result, the mixed solution is phase-separated into the aqueous phase ph1 and the hydrophobic solvent phase ph2, and the oxide particles P1 remaining in the third slurry are moved to the aqueous phase ph1, and the unburned carbon particles P2 are separated. Concentrate to solvent phase ph2. As a result, the content rate of the unburned carbon particles P2 in the solid contained in the solvent phase ph2 can be increased.
上記比重分離工程(S2)の水洗浄工程(S22)では、上記粗分離工程(S21)で回収された溶剤相ph2(第3スラリー)に水L1を加えて混合した後、静置する。これにより、混合液を水相ph1と疎水性溶剤相ph2とに相分離させて、上記第3スラリー中に残存していた酸化物粒子P1を水相ph1に移動させ、未燃カーボン粒子P2を溶剤相ph2に濃縮させる。この結果、溶剤相ph2に含まれる固形物中の未燃カーボン粒子P2の含有率を増加させることができる。 (2) Water washing step with mixing device and separation device (S22)
In the water washing step (S22) of the specific gravity separation step (S2), water L1 is added to and mixed with the solvent phase ph2 (third slurry) recovered in the rough separation step (S21), and then left to stand. As a result, the mixed solution is phase-separated into the aqueous phase ph1 and the hydrophobic solvent phase ph2, and the oxide particles P1 remaining in the third slurry are moved to the aqueous phase ph1, and the unburned carbon particles P2 are separated. Concentrate to solvent phase ph2. As a result, the content rate of the unburned carbon particles P2 in the solid contained in the solvent phase ph2 can be increased.
この水洗浄工程(S22)は、混合装置(ミキサー51B)による混合工程と、分離装置(セトラー52B)による比重分離工程を含む。ミキサー51Bとしては、上述したミキサー51Aと同様な構成の装置を用いることができる。セトラー52Bとしては、上述したセトラー52Aと同様な構成の装置を用いることができる。
This water washing step (S22) includes a mixing step by a mixing device (mixer 51B) and a specific gravity separation step by a separation device (settler 52B). As the mixer 51B, an apparatus having the same configuration as that of the mixer 51A described above can be used. As the settler 52B, an apparatus having the same configuration as that of the above-described settler 52A can be used.
ミキサー51Bの容器内部には、上記セトラー52Aから供給された溶剤相ph2(第3スラリー)が投入される。ミキサー51Bは、モータ511Bにより撹拌翼512Bを回転させることにより、第3スラリーと水L1とを混合して、第4スラリー(未燃カーボン粒子P2と、残存した酸化物粒子P1と、水L1と、疎水性溶剤L2の混合液)を生成する(混合工程)。
The solvent phase ph2 (third slurry) supplied from the settler 52A is charged into the container of the mixer 51B. The mixer 51B rotates the stirring blade 512B by the motor 511B to mix the third slurry and the water L1, and the fourth slurry (unburned carbon particles P2, remaining oxide particles P1, water L1 and , A mixed solution of the hydrophobic solvent L2) (mixing step).
セトラー52Bは、上記ミキサー51Bに対して配管80Bを介して接続されている。また、セトラー52Bは、後段の第1回収装置61に対して配管81Bを介して接続されている。当該配管81Bには、酸化物粒子P1を含む水相ph1(第5スラリー)を送出するためのポンプ71Bが設けられている。さらに、セトラー52Bは、後段の第2回収装置62に対して配管82Bを介して接続されている。当該配管82Bには、未燃カーボン粒子P2を含む溶剤相ph2(第6スラリー)を送出するためのポンプ72Bが設けられている。
The settler 52B is connected to the mixer 51B via a pipe 80B. Further, the settler 52B is connected to the first recovery device 61 at the subsequent stage via a pipe 81B. The pipe 81B is provided with a pump 71B for sending out an aqueous phase ph1 (fifth slurry) containing the oxide particles P1. Further, the settler 52B is connected to the second recovery device 62 at the subsequent stage via a pipe 82B. The pipe 82B is provided with a pump 72B for sending the solvent phase ph2 (sixth slurry) containing unburned carbon particles P2.
セトラー52Bは、上記ミキサー51Bで生成された第4スラリーを静置することにより、水L1と疎水性溶剤L2の比重差を利用して、酸化物粒子P1を主として含む水相ph1と、濃縮された未燃カーボン粒子P2を含む溶剤相ph2とに分離する。その後、酸化物粒子P1を含む水相ph1(第5スラリー)は、セトラー52Bの上部から配管81Bを通じて第1回収装置61に排出される。一方、未燃カーボン粒子P2を含む溶剤相ph2(第6スラリー)は、セトラー52Bの下部から配管82Bを通じて第2回収装置62に排出される。
The settler 52B is concentrated with the aqueous phase ph1 mainly containing the oxide particles P1 by using the difference in specific gravity between the water L1 and the hydrophobic solvent L2 by allowing the fourth slurry generated by the mixer 51B to stand. And separated into a solvent phase ph2 containing unburned carbon particles P2. Thereafter, the aqueous phase ph1 (fifth slurry) containing the oxide particles P1 is discharged from the upper part of the settler 52B to the first recovery device 61 through the pipe 81B. On the other hand, the solvent phase ph2 (sixth slurry) containing the unburned carbon particles P2 is discharged from the lower part of the settler 52B to the second recovery device 62 through the pipe 82B.
(3)第1回収装置による第1回収工程(S3)
第1回収装置61は、上記粗分離工程(S21)及び水洗浄工程(S22)により分離された酸化物粒子P1を含む水相ph1から、水L1を分離して、酸化物粒子P1を回収する。第1回収装置61は、遠心分離機611と、乾燥装置612と、コンデンサー613とを備える。 (3) First recovery step (S3) by the first recovery device
The 1st collection |recovery apparatus 61 isolate | separates the water L1 from the water phase ph1 containing the oxide particle P1 isolate | separated by the said rough | crude separation process (S21) and water washing process (S22), and collect | recovers oxide particles P1. . The first recovery device 61 includes a centrifuge 611, a drying device 612, and a condenser 613.
第1回収装置61は、上記粗分離工程(S21)及び水洗浄工程(S22)により分離された酸化物粒子P1を含む水相ph1から、水L1を分離して、酸化物粒子P1を回収する。第1回収装置61は、遠心分離機611と、乾燥装置612と、コンデンサー613とを備える。 (3) First recovery step (S3) by the first recovery device
The 1st collection |
遠心分離機611は、固液分離装置の一例であり、遠心力を利用して、液体中に懸濁する固体と液体とを分離する。遠心分離機611は、後段の乾燥装置612に対して配管832を介して接続され、前段のミキサー51A、51Bに対して配管831を介して接続されている。遠心分離機611には上記セトラー52A、52Bから酸化物粒子P1を含む水相ph1(第2スラリー、第5スラリー)が導入される。遠心分離機611は、遠心力を利用して、当該スラリーを、酸化物粒子P1を含むケーキC1と、水L1とに分離する(固液分離工程)。遠心分離機611で脱水された酸化物粒子P1は、配管832を通じて乾燥装置612に排出される。一方、遠心分離機611で分離された水L1は、配管831を通じてミキサー51A、51Bに戻されて、上記粗分離工程(S21)と水洗浄工程(S22)にて再利用される。
The centrifuge 611 is an example of a solid-liquid separator, and separates the solid suspended from the liquid and the liquid using centrifugal force. The centrifuge 611 is connected to the subsequent drying device 612 via a pipe 832 and connected to the previous mixers 51A and 51B via a pipe 831. The aqueous phase ph1 (second slurry, fifth slurry) containing the oxide particles P1 is introduced into the centrifuge 611 from the above settlers 52A, 52B. The centrifugal separator 611 uses centrifugal force to separate the slurry into a cake C1 containing oxide particles P1 and water L1 (solid-liquid separation step). The oxide particles P1 dehydrated by the centrifuge 611 are discharged to the drying device 612 through the pipe 832. On the other hand, the water L1 separated by the centrifugal separator 611 is returned to the mixers 51A and 51B through the pipe 831 and reused in the rough separation step (S21) and the water washing step (S22).
なお、本実施形態では、スラリーを水L1と酸化物粒子P1に固液分離するために、遠心分離機611による遠心分離処理を用いるが、これに替えて、フィルタープレス又は蒸留又はろ過等の固液分離方法を用いてもよい。ただし、疎水性溶剤L2が揮発性を有する場合、揮発した溶剤ガスの漏えいを少なくするには、固液分離装置として、例えば、蒸留装置、遠心分離装置、ろ過装置を使用することが好ましい。
In this embodiment, a centrifugal separation process using a centrifuge 611 is used to separate the slurry into water L1 and oxide particles P1, but instead of this, a solidification such as a filter press or distillation or filtration is used. A liquid separation method may be used. However, when the hydrophobic solvent L2 is volatile, it is preferable to use, for example, a distillation device, a centrifugal separator, or a filtration device as the solid-liquid separation device in order to reduce the leakage of the volatilized solvent gas.
乾燥装置612は、上記遠心分離機611から導入された、酸化物粒子P1を含むケーキC1を加熱して、残存する水分を蒸発させる。これにより、酸化物粒子P1を乾燥させる(乾燥工程)。乾燥した酸化物粒子P1は、配管833から排出されて回収される。コンデンサー613は、乾燥装置612から配管834を通じて送出された水蒸気を凝縮して、液体の水L1に戻す(凝縮工程)。コンデンサー613で生成された液体の水L1は、配管835を通じてミキサー51に戻されて、上記粗分離工程(S21)と水洗浄工程(S22)にて再利用される。
The drying device 612 heats the cake C1 including the oxide particles P1 introduced from the centrifuge 611 to evaporate the remaining moisture. Thereby, the oxide particles P1 are dried (drying step). The dried oxide particles P1 are discharged from the pipe 833 and collected. The condenser 613 condenses the water vapor sent from the drying device 612 through the pipe 834 and returns it to the liquid water L1 (condensing step). The liquid water L1 generated by the condenser 613 is returned to the mixer 51 through the pipe 835 and reused in the rough separation step (S21) and the water washing step (S22).
このように、本実施形態に係る分離回収方法では、第1回収工程(S3)にて、上記比重分離工程(S2)により分離された酸化物粒子P1を含む水相ph1(第2、第5スラリー)を、遠心分離機611により、酸化物粒子P1と水L1に分離する。その後に、乾燥装置612で酸化物粒子P1を乾燥させて、乾粉の酸化物粒子P1を回収する。しかし、第1回収工程(S3)は、かかる例に限定されず、上記比重分離工程(S2)により分離された酸化物粒子P1を含む水相ph1(第2、第5スラリー)に対して、上記固液分離工程や乾燥工程を行わずに、そのまま、水スラリー状態の酸化物粒子P1を回収してもよい。酸化物粒子P1を乾粉状態又はケーキ状又は水スラリー状態のいずれで回収するかは、酸化物粒子P1のリサイクル用途等に応じて適宜選択可能である。
Thus, in the separation and recovery method according to the present embodiment, in the first recovery step (S3), the aqueous phase ph1 (second and fifth) containing the oxide particles P1 separated in the specific gravity separation step (S2). Slurry) is separated into oxide particles P1 and water L1 by a centrifugal separator 611. Thereafter, the oxide particles P1 are dried by the drying device 612, and the dried oxide particles P1 are collected. However, the first recovery step (S3) is not limited to such an example, and for the aqueous phase ph1 (second and fifth slurries) containing the oxide particles P1 separated by the specific gravity separation step (S2), You may collect | recover the oxide particle P1 of a water slurry state as it is, without performing the said solid-liquid separation process and a drying process. Whether to collect the oxide particles P1 in a dry powder state, a cake shape, or a water slurry state can be appropriately selected according to the recycling application of the oxide particles P1 and the like.
また、第1回収工程(S3)では、上記比重分離工程(S2)により分離された酸化物粒子P1を含む水相ph1(第2、第5スラリー)に対して、疎水性溶剤L2の沸点以上の温度まで加温する、又は、疎水性溶剤L2が蒸発する気圧まで減圧することにより、当該水相ph1中に残存する疎水性溶剤L2を蒸発させて除去することが好ましい。これにより、回収される酸化物粒子P1に疎水性溶剤L2が含まれることを防止でき、酸化物粒子P1の品質を向上できる。本実施形態に係る分離回収装置5では、図6に示す乾燥装置612による乾燥工程で、水L1とともに疎水性溶剤L2を加熱して蒸発させることで、第2、第5スラリー中に残存している疎水性溶剤L2を除去できる。なお、疎水性溶剤L2が揮発性を有する場合には、常温で蒸発しうるが、疎水性溶剤L2の比重が水L1の比重より大きいことから、疎水性溶剤L2が気相と直接接しないことが多い。このため、撹拌又はエアレーションを行うことが好ましく、このとき、揮発した溶剤L2が飛散しないように対処することが望ましい。
Further, in the first recovery step (S3), the water phase ph1 (second and fifth slurries) containing the oxide particles P1 separated in the specific gravity separation step (S2) is higher than the boiling point of the hydrophobic solvent L2. It is preferable to evaporate and remove the hydrophobic solvent L2 remaining in the aqueous phase ph1 by heating to a temperature of 2 ° C. or by reducing the pressure to a pressure at which the hydrophobic solvent L2 evaporates. Thereby, it can prevent that the hydrophobic solvent L2 is contained in the oxide particle P1 collect | recovered, and can improve the quality of the oxide particle P1. In the separation and recovery device 5 according to the present embodiment, the hydrophobic solvent L2 is heated and evaporated together with the water L1 in the drying process by the drying device 612 shown in FIG. 6 to remain in the second and fifth slurries. The hydrophobic solvent L2 can be removed. In addition, when the hydrophobic solvent L2 has volatility, it can be evaporated at room temperature, but since the specific gravity of the hydrophobic solvent L2 is larger than the specific gravity of the water L1, the hydrophobic solvent L2 should not be in direct contact with the gas phase. There are many. For this reason, it is preferable to perform stirring or aeration, and at this time, it is desirable to take measures so that the volatilized solvent L2 is not scattered.
疎水性溶剤L2を加熱して蒸発させる場合、回収される酸化物粒子P1がケーキ状であるときは、疎水性溶剤L2の沸点は、大気圧下において150℃以下であることが好ましい。これにより、低コストで疎水性溶剤L2を蒸発させて除去することができる。回収される酸化物粒子P1がスラリー状であるときは、疎水性溶剤L2の沸点は、大気圧下において95℃以下であることが好ましい。これにより、水L1の蒸発を抑制することができるので、少ない熱量で容易に疎水性溶剤L2を蒸発させて除去することができる。また、疎水性溶剤L2の沸点は、大気圧下において40℃以上であることが好ましい。これにより、常温大気圧下における疎水性溶剤L2の揮発量を抑制できるので、回収及び取り扱いを容易にできる。
When the hydrophobic solvent L2 is heated and evaporated, when the recovered oxide particles P1 are cake-like, the boiling point of the hydrophobic solvent L2 is preferably 150 ° C. or lower under atmospheric pressure. Thereby, the hydrophobic solvent L2 can be evaporated and removed at low cost. When the recovered oxide particles P1 are in the form of a slurry, the boiling point of the hydrophobic solvent L2 is preferably 95 ° C. or lower under atmospheric pressure. Thereby, since evaporation of the water L1 can be suppressed, the hydrophobic solvent L2 can be easily evaporated and removed with a small amount of heat. Moreover, it is preferable that the boiling point of the hydrophobic solvent L2 is 40 degreeC or more under atmospheric pressure. Thereby, since the volatilization amount of the hydrophobic solvent L2 under normal temperature atmospheric pressure can be suppressed, collection | recovery and handling can be made easy.
(4)第2回収装置による第2回収工程(S4)
第2回収装置62は、上記比重分離工程(S2)により分離された未燃カーボン粒子P2を含む疎水性溶剤相ph2(第6スラリー)から、疎水性溶剤L2を分離、除去して、未燃カーボン粒子P2を主体とする炭素含有粉P0を回収する(S4)。第2回収装置62は、遠心分離機621と、乾燥装置622と、コンデンサー623とを備える。 (4) Second recovery step (S4) by the second recovery device
Thesecond recovery device 62 separates and removes the hydrophobic solvent L2 from the hydrophobic solvent phase ph2 (sixth slurry) containing the unburned carbon particles P2 separated in the specific gravity separation step (S2), and unburned. The carbon-containing powder P0 mainly composed of the carbon particles P2 is collected (S4). The second recovery device 62 includes a centrifuge 621, a drying device 622, and a condenser 623.
第2回収装置62は、上記比重分離工程(S2)により分離された未燃カーボン粒子P2を含む疎水性溶剤相ph2(第6スラリー)から、疎水性溶剤L2を分離、除去して、未燃カーボン粒子P2を主体とする炭素含有粉P0を回収する(S4)。第2回収装置62は、遠心分離機621と、乾燥装置622と、コンデンサー623とを備える。 (4) Second recovery step (S4) by the second recovery device
The
遠心分離機621は、後段の乾燥装置622に対して配管842を介して接続され、前段のミキサー51Aに対して配管841を介して接続されている。遠心分離機621には上記セトラー52Bから上記未燃カーボン粒子P2を含む疎水性溶剤相ph2(第6スラリー)が導入される。遠心分離機621は、遠心力を利用して、当該第6スラリーを、未燃カーボン粒子P2を主体とするケーキC2と、疎水性溶剤L2とに分離する(固液分離工程(S41))。遠心分離機621で疎水性溶剤L2が分離された未燃カーボン粒子P2は、配管842を通じて乾燥装置622に排出される。一方、遠心分離機621で分離された疎水性溶剤L2は、配管841を通じてミキサー51Aに戻されて、上記粗分離工程(S21)にて再利用される。なお、本実施形態では、第6スラリーを疎水性溶剤L2と未燃カーボン粒子P2に固液分離するために、遠心分離機621による遠心分離処理を用いるが、これに替えて、フィルタープレス又は蒸留又はろ過等の固液分離方法を用いてもよい。
The centrifuge 621 is connected to the subsequent drying device 622 via a pipe 842 and connected to the previous mixer 51A via a pipe 841. The hydrophobic solvent phase ph2 (sixth slurry) containing the unburned carbon particles P2 is introduced into the centrifuge 621 from the settler 52B. The centrifugal separator 621 uses centrifugal force to separate the sixth slurry into the cake C2 mainly composed of unburned carbon particles P2 and the hydrophobic solvent L2 (solid-liquid separation step (S41)). Unburned carbon particles P <b> 2 from which the hydrophobic solvent L <b> 2 has been separated by the centrifuge 621 are discharged to the drying device 622 through the pipe 842. On the other hand, the hydrophobic solvent L2 separated by the centrifugal separator 621 is returned to the mixer 51A through the pipe 841 and reused in the rough separation step (S21). In this embodiment, in order to solid-liquid-separate the sixth slurry into the hydrophobic solvent L2 and the unburned carbon particles P2, a centrifugal separation process using a centrifuge 621 is used. Instead, a filter press or a distillation is used. Alternatively, a solid-liquid separation method such as filtration may be used.
乾燥装置622は、上記遠心分離機621から導入された、未燃カーボン粒子P2を含むケーキC2を加熱して、残存する疎水性溶剤成分を揮発させる。これにより、未燃カーボン粒子P2を主体とする固形分を乾燥させて、炭素含有粉P0を得る(乾燥工程(S42))。乾燥した未燃カーボン粒子P2を主体とする炭素含有粉P0は、配管843から排出されて回収される。コンデンサー623は、乾燥装置622から配管844を通じて送出された疎水性溶剤L2の蒸気を凝縮して、液体の疎水性溶剤L2に戻す(凝縮工程)。コンデンサー623で生成された液体の疎水性溶剤L2は、配管845を通じてミキサー51Aに戻されて、上記粗分離工程(S21)にて再利用される(第2リサイクル工程)。
The drying device 622 heats the cake C2 containing the unburned carbon particles P2 introduced from the centrifuge 621 to volatilize the remaining hydrophobic solvent component. Thereby, the solid content mainly composed of the unburned carbon particles P2 is dried to obtain the carbon-containing powder P0 (drying step (S42)). The carbon-containing powder P0 mainly composed of the dried unburned carbon particles P2 is discharged from the pipe 843 and collected. The condenser 623 condenses the vapor of the hydrophobic solvent L2 sent from the drying device 622 through the pipe 844 and returns it to the liquid hydrophobic solvent L2 (condensing step). The liquid hydrophobic solvent L2 generated in the condenser 623 is returned to the mixer 51A through the pipe 845 and reused in the rough separation step (S21) (second recycling step).
このように、本実施形態に係る分離回収方法では、第2回収工程(S4)にて、上記比重分離工程(S2)により分離された未燃カーボン粒子P2を含む溶剤相ph2(第6スラリー)を、遠心分離機621により、未燃カーボン粒子P2を含むケーキC2と、疎水性溶剤L2とに分離する。その後に、乾燥装置622でケーキC2を乾燥させて、乾粉の未燃カーボン粒子P2を主体とする炭素含有粉P0を回収する。
Thus, in the separation and recovery method according to this embodiment, the solvent phase ph2 (sixth slurry) containing unburned carbon particles P2 separated in the specific gravity separation step (S2) in the second recovery step (S4). Is separated into a cake C2 containing unburned carbon particles P2 and a hydrophobic solvent L2 by a centrifugal separator 621. Thereafter, the cake C2 is dried by the drying device 622, and the carbon-containing powder P0 mainly composed of dry unburned carbon particles P2 is recovered.
以上、本実施形態に係る分離回収装置5の構成と、これを用いた炭素含有粉P0の分離回収方法について説明した。本実施形態では、当該方法を単段連続プロセスで行うため、上記の比重分離工程(S2)、第1回収工程(S3)及び第2回収工程(S4)を同時並行で行う。これにより、酸化物粒子P1と未燃カーボン粒子P2の分離効率及び生産性を向上できる。
Heretofore, the configuration of the separation / recovery device 5 according to the present embodiment and the method for separating and collecting the carbon-containing powder P0 using the same have been described. In this embodiment, since the method is performed in a single-stage continuous process, the specific gravity separation step (S2), the first recovery step (S3), and the second recovery step (S4) are performed in parallel. Thereby, the separation efficiency and productivity of the oxide particles P1 and the unburned carbon particles P2 can be improved.
さらに、第1回収工程(S3)にて酸化物粒子P1から分離された水L1を回収して、比重分離工程(S2)で投入される水L1として再利用するとともに、第2回収工程(S4)にて未燃カーボン粒子P2から分離された疎水性溶剤L2を回収して、比重分離工程(S2)で投入される疎水性溶剤L2として再利用する。これにより、水L1及び疎水性溶剤L2を使い捨てにしなくても済むので、疎水性溶剤L2の原料コストや廃棄コストを低減できる。さらに、比重分離工程(S2)で大量の疎水性溶剤L2を繰り返し使用でき、未燃カーボン粒子P2が疎水性溶剤L2に接触する機会を増加できる。また、比重分離工程(S2)の粗分離工程(S21)及び水洗浄工程(S22)では、フライアッシュFAのうち未燃カーボン粒子P2を疎水性溶剤相ph2に取り込み、酸化物粒子P1を水相ph1に取り込むことにより、酸化物粒子P1と未燃カーボン粒子P2を高効率で分離できる。
Further, the water L1 separated from the oxide particles P1 in the first recovery step (S3) is recovered and reused as the water L1 charged in the specific gravity separation step (S2), and the second recovery step (S4). ) To recover the hydrophobic solvent L2 separated from the unburned carbon particles P2 and reuse it as the hydrophobic solvent L2 charged in the specific gravity separation step (S2). Thereby, since it is not necessary to make the water L1 and the hydrophobic solvent L2 disposable, the raw material cost and disposal cost of the hydrophobic solvent L2 can be reduced. Furthermore, a large amount of the hydrophobic solvent L2 can be repeatedly used in the specific gravity separation step (S2), and the chance that the unburned carbon particles P2 come into contact with the hydrophobic solvent L2 can be increased. In the coarse separation step (S21) and the water washing step (S22) of the specific gravity separation step (S2), the unburned carbon particles P2 in the fly ash FA are taken into the hydrophobic solvent phase ph2, and the oxide particles P1 are taken into the water phase. By incorporating it into ph1, the oxide particles P1 and the unburned carbon particles P2 can be separated with high efficiency.
従って、本実施形態に係る炭素含有粉の製造方法における分離回収方法は、上記特許文献1に記載の従来の浮選方法と比べて、酸化物粒子と未燃カーボン粒子の分離速度及び分離効率を大幅に向上できる。例えば、本実施形態に係る粗分離工程(S21)により、例えば1秒~30秒程度の短時間で酸化物粒子P1と未燃カーボン粒子P2を迅速に分離できる。また、分離及び回収された酸化物粒子P1に混在する未燃カーボン粒子P2の含有率を、3質量%以下に低減でき、純度の高い酸化物粒子P1を回収できる。同様に、分離及び回収された炭素含有粉P0に混在する酸化物粒子P1の含有率を、50質量%未満、好ましくは30質量%以下に低減できる。従って、当該炭素含有粉P0に含まれる未燃カーボン粒子P2の含有率を50質量%以上に増加できるので、炭素含有率が高く、かつN/C比の低い炭素含有粉P0を回収できる。
Therefore, the separation and recovery method in the method for producing a carbon-containing powder according to the present embodiment has a separation rate and separation efficiency of oxide particles and unburned carbon particles as compared with the conventional flotation method described in Patent Document 1. Can greatly improve. For example, the rough separation step (S21) according to the present embodiment can quickly separate the oxide particles P1 and the unburned carbon particles P2 in a short time, for example, about 1 second to 30 seconds. Moreover, the content rate of the unburned carbon particle P2 mixed in the separated and recovered oxide particles P1 can be reduced to 3% by mass or less, and the oxide particles P1 having high purity can be recovered. Similarly, the content rate of the oxide particles P1 mixed in the separated and recovered carbon-containing powder P0 can be reduced to less than 50% by mass, preferably 30% by mass or less. Therefore, since the content rate of the unburned carbon particles P2 contained in the carbon-containing powder P0 can be increased to 50% by mass or more, the carbon-containing powder P0 having a high carbon content and a low N / C ratio can be recovered.
[4.1.比重分離の好ましい条件]
次に、本実施形態に係る分離方法における比重分離の好ましい条件について詳細に説明する。まず、本実施形態に係る分離方法で用いられる疎水性溶剤の比重(液比重)の好ましい範囲について説明する。 [4.1. Preferred conditions for specific gravity separation]
Next, preferable conditions for specific gravity separation in the separation method according to the present embodiment will be described in detail. First, a preferable range of the specific gravity (liquid specific gravity) of the hydrophobic solvent used in the separation method according to the present embodiment will be described.
次に、本実施形態に係る分離方法における比重分離の好ましい条件について詳細に説明する。まず、本実施形態に係る分離方法で用いられる疎水性溶剤の比重(液比重)の好ましい範囲について説明する。 [4.1. Preferred conditions for specific gravity separation]
Next, preferable conditions for specific gravity separation in the separation method according to the present embodiment will be described in detail. First, a preferable range of the specific gravity (liquid specific gravity) of the hydrophobic solvent used in the separation method according to the present embodiment will be described.
上記の粗分離工程(S21)又は水洗浄工程(S22)における静置時には、水相と疎水性溶剤相との界面付近に、酸化物粒子と未燃カーボン粒子の濃縮が生じる場合がある。例えば、疎水性溶剤としてのトリクロロエチレン(比重:1.46)と水(比重:1)を混合した混合液に、親水性粒子としての酸化物粒子(比重:2.4~2.6)を主体とする混合物(例えばフライアッシュ)を投入し、約30秒以上静置する。酸化物粒子は、水相中を沈降する一方、未燃カーボン粒子(比重:1.3~1.5)は、トリクロロエチレン相中を浮上する。この結果、水相とトリクロロエチレン相の界面付近では、酸化物粒子と未燃カーボン粒子が濃縮して、徐々に比重が近くなる。当該界面付近では、酸化物粒子と未燃カーボン粒子が混在した状態となるので、両者の分離性が悪化する場合がある。よって、酸化物粒子と未燃カーボン粒子との分離性が悪化するのを防ぐため、静置後短時間で水相と疎水性溶剤相を分離することが好ましく、さらに、両相の界面付近を採取しないことが好ましい場合がある。
When standing in the above rough separation step (S21) or water washing step (S22), the oxide particles and unburned carbon particles may concentrate near the interface between the aqueous phase and the hydrophobic solvent phase. For example, a mixture of trichlorethylene (specific gravity: 1.46) as a hydrophobic solvent and water (specific gravity: 1) is mixed with oxide particles (specific gravity: 2.4 to 2.6) as hydrophilic particles. A mixture (for example, fly ash) is added and left to stand for about 30 seconds or more. The oxide particles settle in the aqueous phase, while the unburned carbon particles (specific gravity: 1.3 to 1.5) float in the trichlorethylene phase. As a result, near the interface between the water phase and the trichlorethylene phase, the oxide particles and the unburned carbon particles are concentrated, and the specific gravity gradually approaches. In the vicinity of the interface, oxide particles and unburned carbon particles are mixed, so that the separation between them may be deteriorated. Therefore, in order to prevent the separation between the oxide particles and the unburned carbon particles from deteriorating, it is preferable to separate the aqueous phase and the hydrophobic solvent phase in a short time after standing, and further, the vicinity of the interface between the two phases. It may be preferable not to collect.
酸化物粒子の比重が大きいほど、比重が大きい疎水性溶剤を選択することが好ましい。これにより、酸化物粒子が水相から溶剤相に沈降することを防止できる。なお、酸化物粒子の比重が小さい場合には、比重が小さい疎水性溶剤を敢えて選択する必要はなく、適用できる疎水性溶剤の比重の範囲を拡張できる。
As the specific gravity of the oxide particles is larger, it is preferable to select a hydrophobic solvent having a larger specific gravity. Thereby, it can prevent that oxide particle settles from a water phase to a solvent phase. When the specific gravity of the oxide particles is small, it is not necessary to dare to select a hydrophobic solvent having a small specific gravity, and the range of applicable specific gravity of the hydrophobic solvent can be expanded.
水相(すなわち水と酸化物粒子のスラリー)に含まれる酸化物粒子の質量割合を、水相のスラリー濃度CS[質量%]とする。スラリー濃度CSは、以下の式(2)で表される。水相の見掛け密度ρS[g/cm3]を、同温度及び同圧力における水の密度ρw[g/cm3]で除算した値を、水相のスラリー比重dSとする。スラリー比重dSは、以下の式(3)で表される。
The mass ratio of the oxide particles contained in the aqueous phase (that is, the slurry of water and oxide particles) is defined as the slurry concentration C S [mass%] of the aqueous phase. The slurry concentration CS is represented by the following formula (2). The value obtained by dividing the apparent density ρ S [g / cm 3 ] of the aqueous phase by the density ρ w [g / cm 3 ] of water at the same temperature and pressure is defined as the slurry specific gravity d S of the aqueous phase. The slurry specific gravity d S is represented by the following formula (3).
CS=mP/(mP+mW) ・・・(2)
dS=ρS/ρw=(mP+mW)/(VP+VW)/ρw ・・・(3)
mP[g] :水相に含まれる酸化物粒子の質量
mW[g] :水相に含まれる水の質量
VP[cm3] :水相に含まれる酸化物粒子の体積
VW[cm3] :水相に含まれる水の体積
ρS[g/cm3]:水相における水と酸化物粒子のスラリーの見掛け密度
ρw[g/cm3]:同温度及び同圧力における水の密度 C S = m P / (m P + m W ) (2)
d S = ρ S / ρ w = (m P + m W ) / (V P + V W ) / ρ w (3)
m P [g]: Mass of oxide particles contained in water phase m W [g]: Mass of water contained in water phase V P [cm 3 ]: Volume of oxide particles contained in water phase V W [ cm 3 ]: Volume of water contained in the aqueous phase ρ S [g / cm 3 ]: Apparent density of slurry of water and oxide particles in the aqueous phase ρ w [g / cm 3 ]: Water at the same temperature and pressure Density of
dS=ρS/ρw=(mP+mW)/(VP+VW)/ρw ・・・(3)
mP[g] :水相に含まれる酸化物粒子の質量
mW[g] :水相に含まれる水の質量
VP[cm3] :水相に含まれる酸化物粒子の体積
VW[cm3] :水相に含まれる水の体積
ρS[g/cm3]:水相における水と酸化物粒子のスラリーの見掛け密度
ρw[g/cm3]:同温度及び同圧力における水の密度 C S = m P / (m P + m W ) (2)
d S = ρ S / ρ w = (m P + m W ) / (V P + V W ) / ρ w (3)
m P [g]: Mass of oxide particles contained in water phase m W [g]: Mass of water contained in water phase V P [cm 3 ]: Volume of oxide particles contained in water phase V W [ cm 3 ]: Volume of water contained in the aqueous phase ρ S [g / cm 3 ]: Apparent density of slurry of water and oxide particles in the aqueous phase ρ w [g / cm 3 ]: Water at the same temperature and pressure Density of
水相のスラリー比重が疎水性溶剤の比重未満であれば、水相は溶剤相中に沈降しにくく、水相と溶剤相の相分離を好適に行うために有利であるといえる。よって、上記沈降が抑制されるよう、混合工程における混合物(フライアッシュ)と水の混合比を調整したり、適切な比重の疎水性溶剤を選択したりすることが好ましい。
If the slurry specific gravity of the aqueous phase is less than the specific gravity of the hydrophobic solvent, the aqueous phase is unlikely to settle in the solvent phase, which is advantageous for suitably performing phase separation between the aqueous phase and the solvent phase. Therefore, it is preferable to adjust the mixing ratio of the mixture (fly ash) and water in the mixing step or to select a hydrophobic solvent having an appropriate specific gravity so that the settling is suppressed.
また、疎水性溶剤の比重は、1.05超であることがより好ましい。疎水性溶剤の比重が1.05以下である場合、上記のように水相のスラリー比重dSを疎水性溶剤の比重未満とするためには、水相のスラリー濃度CSを所定値以下に低くする必要がある。この場合、分離装置が大型化してしまうおそれがある。これに対し、疎水性溶剤の比重を1.05超とすることにより、水相のスラリー濃度CSを上記所定値を超えて高くできるので、単位時間当たりの分離処理量を高めて、大型の分離装置を使用しなくてすむ。
The specific gravity of the hydrophobic solvent is more preferably more than 1.05. When the specific gravity of the hydrophobic solvent is 1.05 or less, in order to make the slurry specific gravity d S of the aqueous phase less than the specific gravity of the hydrophobic solvent as described above, the slurry concentration C S of the aqueous phase is set to a predetermined value or less. Need to be low. In this case, there exists a possibility that a separation apparatus may enlarge. In contrast, by 1.05 than the specific gravity of the hydrophobic solvent, the slurry concentration C S in the aqueous phase can be higher than the predetermined value, to increase the separation processing amount per unit time, a large There is no need to use a separator.
また、溶剤相中において、水滴に付着できなかった酸化物粒子の表面に、薄い(例えば約5~20μmの)水被膜が付着する場合もある。当該水被膜で被覆された酸化物粒子(以下、「水被膜粒子」ともいう。)の見掛け比重は、酸化物粒子自体の比重より小さくなる。よって、水被膜粒子の見掛け比重より大きい比重の疎水性溶剤を選択することが好ましい。これにより、上記分離工程において、水被膜粒子を溶剤相から水相に浮上させて、水相内に滞留させることができる。よって、酸化物粒子を、疎水性溶剤及び未燃カーボン粒子から迅速かつ効率的に分離できる。水被膜粒子の見掛け比重を直接測定することが困難である場合、例えば、栓付メスシリンダーに水80mlと疎水性溶剤20mlからなる混合液に酸化物粒子を0.5~1g入れ、そのとき酸化物粒子のほとんどが溶剤相に沈降しないような疎水性溶剤を選択することが好ましい。
In the solvent phase, a thin (for example, about 5 to 20 μm) water film may adhere to the surface of the oxide particles that could not adhere to the water droplets. The apparent specific gravity of the oxide particles coated with the water coating (hereinafter also referred to as “water coating particles”) is smaller than the specific gravity of the oxide particles themselves. Therefore, it is preferable to select a hydrophobic solvent having a specific gravity larger than the apparent specific gravity of the water coating particles. Thereby, in the said isolation | separation process, water film particle | grains can be floated from a solvent phase to an aqueous phase, and can be made to retain in an aqueous phase. Thus, the oxide particles can be quickly and efficiently separated from the hydrophobic solvent and the unburned carbon particles. If it is difficult to directly measure the apparent specific gravity of the water-coated particles, for example, 0.5 to 1 g of oxide particles are put into a mixed liquid consisting of 80 ml of water and 20 ml of a hydrophobic solvent in a measuring cylinder with a stopper. It is preferable to select a hydrophobic solvent in which most of the product particles do not settle in the solvent phase.
さらに、疎水性溶剤の比重は、未燃カーボン粒子の比重よりも小さいことが好ましい。これにより、上記第2回収工程(S4)において、遠心分離機621を用いて溶剤相ph2(第3スラリー)から未燃カーボン粒子P2を分離する際、脱液性が向上し、未燃カーボン粒子P2を効率的に分離できる。なお、「未燃カーボン粒子P2の比重<疎水性溶剤L2の比重」となる場合でも、脱液性は劣るが遠心分離機を使用でき、或いは、ろ過方式又は蒸留方式の固液分離装置を採用することもできる。
Furthermore, the specific gravity of the hydrophobic solvent is preferably smaller than the specific gravity of the unburned carbon particles. Thus, in the second recovery step (S4), when the unburned carbon particles P2 are separated from the solvent phase ph2 (third slurry) using the centrifuge 621, the liquid removal property is improved, and the unburned carbon particles are improved. P2 can be separated efficiently. Even when “the specific gravity of the unburned carbon particles P2 <the specific gravity of the hydrophobic solvent L2,” a centrifuge can be used although the liquid removal property is inferior, or a solid-liquid separation device of a filtration method or a distillation method is employed. You can also
次に、本実施形態に係る分離方法で用いられる粒子の粒子径又は比重の好ましい範囲について説明する。酸化物粒子が水相中を沈降し、水相と疎水性溶剤相との界面に到達した状態で、当該酸化物粒子には、浮力と界面張力と重力とが作用する。界面張力は、上記界面において、粒子が一方の相から他方の相へ移動することを阻害するエネルギー障壁として作用する。これらの力のバランスによって、酸化物粒子がどちらの相に移動するのかが決まるとも言える。酸化物粒子に作用する浮力と界面張力との合計を重力が上回る程度に、酸化物粒子の粒子径が大きいか、又は水の比重に対して酸化物粒子の比重が大きいと、当該粒子が水相から界面を通過して溶剤相へ移動してしまうと考えられる。この場合、酸化物粒子と未燃カーボン粒子との分離効率が低下する。この観点からは、界面を通過して溶剤相へ移動してしまう程度に粒子径が大きいか又は比重が大きい酸化物粒子を、分離処理の前に除いておくことが好ましい。例えば、分離処理前のフライアッシュに含まれる酸化物粒子の粒子径は、500μm以下であってよく、200μm以下であることが好ましい。
Next, a preferable range of the particle diameter or specific gravity of the particles used in the separation method according to this embodiment will be described. With the oxide particles settling in the aqueous phase and reaching the interface between the aqueous phase and the hydrophobic solvent phase, buoyancy, interfacial tension, and gravity act on the oxide particles. Interfacial tension acts as an energy barrier that inhibits particles from moving from one phase to the other at the interface. It can be said that the balance of these forces determines which phase the oxide particles move to. If the particle diameter of the oxide particles is large enough that gravity exceeds the total of the buoyancy and interfacial tension acting on the oxide particles, or if the specific gravity of the oxide particles is large relative to the specific gravity of water, the particles It is thought that it moves from the phase to the solvent phase through the interface. In this case, the separation efficiency between the oxide particles and the unburned carbon particles decreases. From this point of view, it is preferable to remove oxide particles having a particle diameter or a specific gravity large enough to pass through the interface and move to the solvent phase before the separation treatment. For example, the particle size of the oxide particles contained in the fly ash before the separation treatment may be 500 μm or less, and preferably 200 μm or less.
疎水性溶剤相中を浮上し、界面に到達した未燃カーボン粒子についても上記と同様である。未燃カーボン粒子に作用する重力と界面張力との合計を浮力が上回る程度に、未燃カーボン粒子の粒子径が大きいか、又は疎水性溶剤の比重に対して未燃カーボン粒子の比重が小さいと、当該粒子が溶剤相から界面を通過して水相へ移動してしまうと考えられる。この観点からは、界面を通過して水相へ移動してしまう程度に粒子径が大きいか又は比重が小さい未燃カーボン粒子を、分離処理の前に除いておくことが好ましい。例えば、分離処理前のフライアッシュに含まれる未燃カーボン粒子の粒子径は、500μm以下であってよく、200μm以下であることが好ましい。なお、これら最大粒子径は、篩による篩分けや、サイクロンによる分級をすることでコントロールすることができる。
The same applies to the unburned carbon particles that floated in the hydrophobic solvent phase and reached the interface. When the particle size of the unburned carbon particles is large, or the specific gravity of the unburned carbon particles is small relative to the specific gravity of the hydrophobic solvent, so that the buoyancy exceeds the sum of gravity and interfacial tension acting on the unburned carbon particles. The particles are considered to move from the solvent phase to the aqueous phase through the interface. From this point of view, it is preferable to remove the unburned carbon particles having a particle diameter or a specific gravity small enough to pass through the interface and move to the aqueous phase before the separation treatment. For example, the particle size of the unburned carbon particles contained in the fly ash before the separation treatment may be 500 μm or less, and preferably 200 μm or less. These maximum particle sizes can be controlled by sieving with a sieve or classification with a cyclone.
[5.粉砕工程を伴う分離回収方法]
次に、本発明の第2の実施形態に係る炭素含有粉の製造方法について説明する。第2の実施形態に係る製造方法は、回収される炭素含有粉中の炭素含有率を高めるために、フライアッシュ中の未燃カーボン粒子を粉砕する粉砕工程をさらに含むことを特徴とする。 [5. Separation and recovery method with pulverization process]
Next, the manufacturing method of the carbon containing powder which concerns on the 2nd Embodiment of this invention is demonstrated. The manufacturing method according to the second embodiment further includes a pulverizing step of pulverizing unburned carbon particles in fly ash in order to increase the carbon content in the carbon-containing powder to be recovered.
次に、本発明の第2の実施形態に係る炭素含有粉の製造方法について説明する。第2の実施形態に係る製造方法は、回収される炭素含有粉中の炭素含有率を高めるために、フライアッシュ中の未燃カーボン粒子を粉砕する粉砕工程をさらに含むことを特徴とする。 [5. Separation and recovery method with pulverization process]
Next, the manufacturing method of the carbon containing powder which concerns on the 2nd Embodiment of this invention is demonstrated. The manufacturing method according to the second embodiment further includes a pulverizing step of pulverizing unburned carbon particles in fly ash in order to increase the carbon content in the carbon-containing powder to be recovered.
[5.1.粉砕工程を伴う分離回収方法のフロー]
図7~図10は、第2の実施形態に係る製造方法における分離回収方法を示す工程図である。図7~図10に示すように、第2の実施形態に係る分離回収方法では、上述した第1の実施形態に係る分離回収方法(図5参照。)と比べて、粉砕工程(S5)が追加されている。このうち、図7~図9に示す工程例では、上記比重分離工程(S2)の粗分離工程(S21)の前に、粉砕工程(S5)が追加されている。一方、図10に示す工程例では、上記比重分離工程(S2)の途中に、具体的には粗分離工程(S21)と水洗浄工程(S22)の間に、粉砕工程(S5)が追加されている。 [5.1. Flow of separation and recovery method with pulverization process]
7 to 10 are process diagrams showing a separation and recovery method in the manufacturing method according to the second embodiment. As shown in FIGS. 7 to 10, in the separation and recovery method according to the second embodiment, compared with the separation and recovery method according to the first embodiment (see FIG. 5), the pulverization step (S5) is performed. Have been added. Among these, in the process examples shown in FIGS. 7 to 9, the pulverization step (S5) is added before the coarse separation step (S21) of the specific gravity separation step (S2). On the other hand, in the process example shown in FIG. 10, a pulverization step (S5) is added during the specific gravity separation step (S2), specifically, between the rough separation step (S21) and the water washing step (S22). ing.
図7~図10は、第2の実施形態に係る製造方法における分離回収方法を示す工程図である。図7~図10に示すように、第2の実施形態に係る分離回収方法では、上述した第1の実施形態に係る分離回収方法(図5参照。)と比べて、粉砕工程(S5)が追加されている。このうち、図7~図9に示す工程例では、上記比重分離工程(S2)の粗分離工程(S21)の前に、粉砕工程(S5)が追加されている。一方、図10に示す工程例では、上記比重分離工程(S2)の途中に、具体的には粗分離工程(S21)と水洗浄工程(S22)の間に、粉砕工程(S5)が追加されている。 [5.1. Flow of separation and recovery method with pulverization process]
7 to 10 are process diagrams showing a separation and recovery method in the manufacturing method according to the second embodiment. As shown in FIGS. 7 to 10, in the separation and recovery method according to the second embodiment, compared with the separation and recovery method according to the first embodiment (see FIG. 5), the pulverization step (S5) is performed. Have been added. Among these, in the process examples shown in FIGS. 7 to 9, the pulverization step (S5) is added before the coarse separation step (S21) of the specific gravity separation step (S2). On the other hand, in the process example shown in FIG. 10, a pulverization step (S5) is added during the specific gravity separation step (S2), specifically, between the rough separation step (S21) and the water washing step (S22). ing.
まず、図7に示す工程例について説明する。図7に示すように、まず、フライアッシュFAと水L1と疎水性溶剤L2との混合液に対して、粉砕処理を行う(S5)。これにより、図2に示すように未燃カーボン粒子P2の表面に酸化物粒子P1が付着し、又は未燃カーボン粒子P2の細孔P20内に酸化物粒子P1が入り込んでいても、粉砕処理により、図3に示すように未燃カーボン粒子P2が粉砕されて微細化する。この結果、一部の細孔P20内の酸化物粒子P1が放出されるので、微細化した未燃カーボン粒子P2と、酸化物粒子P1とが分離されるか、少なくとも分離され易くなる。
First, the process example shown in FIG. 7 will be described. As shown in FIG. 7, first, a pulverization process is performed on a mixed solution of fly ash FA, water L1, and hydrophobic solvent L2 (S5). As a result, even if the oxide particles P1 adhere to the surface of the unburned carbon particles P2 or the oxide particles P1 enter the pores P20 of the unburned carbon particles P2 as shown in FIG. As shown in FIG. 3, the unburned carbon particles P2 are pulverized and refined. As a result, since the oxide particles P1 in some of the pores P20 are released, the refined unburnt carbon particles P2 and the oxide particles P1 are separated or at least easily separated.
かかる粉砕工程(S5)後に、第1の実施形態と同様に、比重分離工程(S2)の粗分離工程(S21)と水洗浄工程(S22)を行う。これにより、粉砕された未燃カーボン粒子P2は、酸化物粒子P1から分離して溶剤相ph2に移動し易くなり、酸化物粒子P1も未燃カーボン粒子P2から分離して水相ph1に移動し易くなる。従って、比重分離工程(S2)において、酸化物粒子P1と未燃カーボン粒子P2をさらに好適に分離できるので、回収工程(S4)で回収される炭素含有粉P0の炭素含有率を70質量%以上に高めることができる。
After the pulverization step (S5), as in the first embodiment, the coarse separation step (S21) and the water washing step (S22) of the specific gravity separation step (S2) are performed. Thereby, the pulverized unburned carbon particles P2 are easily separated from the oxide particles P1 and moved to the solvent phase ph2, and the oxide particles P1 are also separated from the unburned carbon particles P2 and moved to the water phase ph1. It becomes easy. Therefore, in the specific gravity separation step (S2), the oxide particles P1 and the unburned carbon particles P2 can be more preferably separated, so that the carbon content of the carbon-containing powder P0 recovered in the recovery step (S4) is 70 mass% or more. Can be increased.
また、粗分離工程(S21)で分離した酸化物粒子P1を含む水相ph1を、固液分離し乾燥させることで、酸化物の粉体を得ることができる。粉砕工程(S5)で粉砕処理しているため、処理前のフライアッシュFAと比べて、酸化物粒子P1に付随する未燃カーボン粒子P2は少なくなり、水相ph1から得られる固形物中の炭素含有率は大きく低下する。当該炭素含有率は、粉砕工程を有さない図5の粗分離工程(S21)で分離した酸化物粒子P1を含む水相ph1から回収した固形物中の炭素含有率と比較しても、大きく低下する。
Further, oxide powder can be obtained by solid-liquid separation and drying the aqueous phase ph1 containing the oxide particles P1 separated in the rough separation step (S21). Since the pulverization process is performed in the pulverization step (S5), the unburned carbon particles P2 associated with the oxide particles P1 are reduced compared to the fly ash FA before the process, and the carbon in the solid matter obtained from the aqueous phase ph1. The content is greatly reduced. The carbon content is large even when compared with the carbon content in the solid recovered from the aqueous phase ph1 containing the oxide particles P1 separated in the rough separation step (S21) of FIG. descend.
次に、図8、図9の工程例について説明する。図8に示すように、まず、フライアッシュFAと水L1との混合液に対して、粉砕処理を行う(S5)。これにより、上記図7の例と同様に、未燃カーボン粒子P2が粉砕されて微細化し、未燃カーボン粒子P2と酸化物粒子P1が分離され易くなる。次いで、比重分離工程(S2)の粗分離工程(S21)で、粉砕された混合液に疎水性溶剤L2を加えて混合し、この混合液を比重分離した後に、水洗浄工程(S22)を行う。
Next, the process example of FIGS. 8 and 9 will be described. As shown in FIG. 8, first, a pulverization process is performed on the mixed solution of fly ash FA and water L1 (S5). Thereby, similarly to the example of FIG. 7, the unburned carbon particles P2 are pulverized and refined, and the unburned carbon particles P2 and the oxide particles P1 are easily separated. Next, in the coarse separation step (S21) of the specific gravity separation step (S2), the hydrophobic solvent L2 is added to and mixed with the pulverized mixed solution, and the mixed solution is separated by specific gravity, and then the water washing step (S22) is performed. .
また、図9の工程例では、まず、フライアッシュFAと疎水性溶剤L2との混合液に対して、粉砕処理を行う(S5)。これにより、上記図7の例と同様に、未燃カーボン粒子P2が粉砕されて微細化し、未燃カーボン粒子P2と酸化物粒子P1が分離され易くなる。次いで、比重分離工程(S2)の粗分離工程(S21)で、粉砕された混合液に水L1を加えて混合し、この混合液を比重分離した後に、水洗浄工程(S22)を行う。
In the process example of FIG. 9, first, a pulverization process is performed on the mixed solution of fly ash FA and the hydrophobic solvent L2 (S5). Thereby, similarly to the example of FIG. 7, the unburned carbon particles P2 are pulverized and refined, and the unburned carbon particles P2 and the oxide particles P1 are easily separated. Next, in the coarse separation step (S21) of the specific gravity separation step (S2), water L1 is added to the pulverized mixed solution and mixed, and this mixed solution is separated by specific gravity, followed by the water washing step (S22).
このように、図8及び図9の例では、最初に粉砕工程(S5)で、フライアッシュFAに水L1又は疎水性溶剤L2のいずれか一方を加えた混合液に対して粉砕処理を施した後に、比重分離工程(S2)で、粉砕後の混合液に水L1又は疎水性溶剤L2の他方を加えて混合した後に、比重分離する。かかる工程順でも、比重分離工程(S2)において、酸化物粒子P1と未燃カーボン粒子P2をさらに好適に分離できるので、回収工程(S4)で回収される炭素含有粉P0中の炭素含有率を70質量%以上に高めることができる。
As described above, in the examples of FIGS. 8 and 9, first, in the pulverization step (S5), the mixed liquid obtained by adding either water L1 or hydrophobic solvent L2 to fly ash FA was pulverized. Later, in the specific gravity separation step (S2), the other of the water L1 or the hydrophobic solvent L2 is added to and mixed with the pulverized mixed solution, and then the specific gravity is separated. Even in this order of steps, since the oxide particles P1 and the unburned carbon particles P2 can be more suitably separated in the specific gravity separation step (S2), the carbon content in the carbon-containing powder P0 recovered in the recovery step (S4) is reduced. It can be increased to 70% by mass or more.
また、粗分離工程(S21)で分離した酸化物粒子P1を含む水相ph1を、固液分離し乾燥させることで、酸化物の粉体を得ることができる。粉砕工程(S5)で粉砕処理しているため、処理前のフライアッシュFAと比べて、酸化物粒子P1に付随する未燃カーボン粒子P2は少なくなり、水相ph1から得られる固形物中の炭素含有率は大きく低下する。当該炭素含有率は、粉砕工程を有さない図5の粗分離工程(S21)で分離した酸化物粒子P1を含む水相ph1から回収した固形物中の炭素含有率と比較しても、大きく低下する。
Further, oxide powder can be obtained by solid-liquid separation and drying the aqueous phase ph1 containing the oxide particles P1 separated in the rough separation step (S21). Since the pulverization process is performed in the pulverization step (S5), the unburned carbon particles P2 associated with the oxide particles P1 are reduced compared to the fly ash FA before the process, and the carbon in the solid matter obtained from the aqueous phase ph1. The content is greatly reduced. The carbon content is large even when compared with the carbon content in the solid recovered from the aqueous phase ph1 containing the oxide particles P1 separated in the rough separation step (S21) of FIG. descend.
次に、図10の工程例について説明する。図10に示すように、まず、粗分離工程(S21)にて、フライアッシュFAと水L1と疎水性溶剤L2の混合液に対して粗分離処理を行う。これにより、第1の実施形態(図5参照。)と同様に、混合液が、酸化物粒子P1を主に含む水相ph1と、未燃カーボン粒子P2を主に含む疎水性溶剤相ph2とに分離される。その後、当該分離された疎水性溶剤相ph2を回収し、粉砕工程(S5)で、疎水性溶剤相ph2に対してのみ粉砕処理を行い、水相ph1に対しては粉砕処理を行わない。かかる粉砕処理により、疎水性溶剤相ph2に含まれる未燃カーボン粒子P2が粉砕されて微細化し、残存する酸化物粒子P1から好適に分離され易くなる。従って、その後の水洗浄工程(S22)において、酸化物粒子P1と未燃カーボン粒子P2をさらに好適に分離できるので、回収工程(S4)で回収される炭素含有粉P0中の炭素含有率を70質量%以上に高めることができる。
Next, the process example of FIG. 10 will be described. As shown in FIG. 10, first, in the coarse separation step (S21), a coarse separation process is performed on the mixed solution of fly ash FA, water L1, and hydrophobic solvent L2. As a result, as in the first embodiment (see FIG. 5), the mixed liquid contains an aqueous phase ph1 mainly containing oxide particles P1 and a hydrophobic solvent phase ph2 mainly containing unburned carbon particles P2. Separated. Thereafter, the separated hydrophobic solvent phase ph2 is recovered, and in the pulverization step (S5), only the hydrophobic solvent phase ph2 is pulverized, and the aqueous phase ph1 is not pulverized. By this pulverization treatment, the unburned carbon particles P2 contained in the hydrophobic solvent phase ph2 are pulverized and refined, and are easily separated from the remaining oxide particles P1. Accordingly, in the subsequent water washing step (S22), the oxide particles P1 and the unburned carbon particles P2 can be more preferably separated, so that the carbon content in the carbon-containing powder P0 recovered in the recovery step (S4) is 70. It can be increased to more than mass%.
このように図10に示す工程例では、粗分離工程(S21)で分離、回収された溶剤相ph2中の未燃カーボン粒子P2は、その後の粉砕工程(S5)で粉砕されるが、粗分離工程(S21)で分離、回収された水相ph1中の酸化物粒子P1は粉砕されない。このため、未燃カーボン粒子P2に特化して粉砕処理を実行できるので、未燃カーボン粒子P2の粉砕効率を向上させることができる。一方、上記図7~図9の工程例では、未燃カーボン粒子P2及び酸化物粒子P1の双方が粉砕される。このため、未燃カーボン粒子P2のみならず、酸化物粒子P1も粉砕し、微粉化された酸化物粒子P1を回収したい場合には、未燃カーボン粒子P2と酸化物粒子P1の粉砕工程を一元化できるので、有益な方法である。
Thus, in the process example shown in FIG. 10, the unburned carbon particles P2 in the solvent phase ph2 separated and recovered in the coarse separation step (S21) are crushed in the subsequent pulverization step (S5). The oxide particles P1 in the aqueous phase ph1 separated and recovered in the step (S21) are not pulverized. For this reason, since the pulverization process can be executed specifically for the unburned carbon particles P2, the pulverization efficiency of the unburned carbon particles P2 can be improved. On the other hand, in the process examples of FIGS. 7 to 9, both the unburned carbon particles P2 and the oxide particles P1 are pulverized. For this reason, when not only the unburned carbon particles P2 but also the oxide particles P1 are pulverized and the finely divided oxide particles P1 are to be recovered, the pulverization process of the unburned carbon particles P2 and the oxide particles P1 is unified. It is a useful method because it can.
[5.2.粉砕工程で用いる粉砕方法]
次に、上記粉砕工程(S5)における粉砕方法の具体例について説明する。上述したように、粉砕工程(S5)における粉砕方法としては、例えば、超音波による粉砕処理、高速せん断ミキサーによる粉砕処理、ボールミル又はビーズミルによる粉砕処理などを利用できる。このうち、ビーズミルによる粉砕処理では、例えば、円筒容器内に球形のビーズを充填し、粉砕対象物としての混合物(例えばフライアッシュ)を供給しながら撹拌部材を回転させる。これにより、撹拌される粉砕対象物とビーズとの間に衝突力又はせん断力を作用させて、粉砕対象物を粉砕する。かかるビーズを用いた粉砕処理により、例えばフライアッシュ中に含まれる硬い酸化物粒子P1を破壊せずに、多孔質であり脆い未燃カーボン粒子P2を、短時間で効率的に粉砕できる。このため、未燃カーボン粒子の分離性を向上させて、回収される炭素含有粉中の炭素含有率を増加させ、かつ、回収される酸化物中の炭素含有率を低減することができる。 [5.2. Grinding method used in the grinding process]
Next, a specific example of the pulverization method in the pulverization step (S5) will be described. As described above, as a pulverization method in the pulverization step (S5), for example, a pulverization process using ultrasonic waves, a pulverization process using a high-speed shear mixer, a pulverization process using a ball mill or a bead mill can be used. Among these, in the pulverization process by the bead mill, for example, spherical beads are filled in a cylindrical container, and the stirring member is rotated while supplying a mixture (for example, fly ash) as an object to be pulverized. Thereby, a collision force or a shearing force is applied between the pulverized object to be stirred and the beads, and the pulverized object is pulverized. By pulverizing using such beads, for example, porous and brittle unburned carbon particles P2 can be efficiently pulverized in a short time without destroying the hard oxide particles P1 contained in the fly ash. For this reason, the separability of unburned carbon particles can be improved, the carbon content in the recovered carbon-containing powder can be increased, and the carbon content in the recovered oxide can be reduced.
次に、上記粉砕工程(S5)における粉砕方法の具体例について説明する。上述したように、粉砕工程(S5)における粉砕方法としては、例えば、超音波による粉砕処理、高速せん断ミキサーによる粉砕処理、ボールミル又はビーズミルによる粉砕処理などを利用できる。このうち、ビーズミルによる粉砕処理では、例えば、円筒容器内に球形のビーズを充填し、粉砕対象物としての混合物(例えばフライアッシュ)を供給しながら撹拌部材を回転させる。これにより、撹拌される粉砕対象物とビーズとの間に衝突力又はせん断力を作用させて、粉砕対象物を粉砕する。かかるビーズを用いた粉砕処理により、例えばフライアッシュ中に含まれる硬い酸化物粒子P1を破壊せずに、多孔質であり脆い未燃カーボン粒子P2を、短時間で効率的に粉砕できる。このため、未燃カーボン粒子の分離性を向上させて、回収される炭素含有粉中の炭素含有率を増加させ、かつ、回収される酸化物中の炭素含有率を低減することができる。 [5.2. Grinding method used in the grinding process]
Next, a specific example of the pulverization method in the pulverization step (S5) will be described. As described above, as a pulverization method in the pulverization step (S5), for example, a pulverization process using ultrasonic waves, a pulverization process using a high-speed shear mixer, a pulverization process using a ball mill or a bead mill can be used. Among these, in the pulverization process by the bead mill, for example, spherical beads are filled in a cylindrical container, and the stirring member is rotated while supplying a mixture (for example, fly ash) as an object to be pulverized. Thereby, a collision force or a shearing force is applied between the pulverized object to be stirred and the beads, and the pulverized object is pulverized. By pulverizing using such beads, for example, porous and brittle unburned carbon particles P2 can be efficiently pulverized in a short time without destroying the hard oxide particles P1 contained in the fly ash. For this reason, the separability of unburned carbon particles can be improved, the carbon content in the recovered carbon-containing powder can be increased, and the carbon content in the recovered oxide can be reduced.
また、上記ビーズミルによる粉砕処理で使用するビーズの直径(以下、ビーズ径という。)は、1mm以下であることが好ましい。略球状の酸化物粒子は中実であり、硬く砕きにくいが、未燃カーボン粒子は多孔質であるため、脆く容易に砕ける。一方、略球状の酸化物粒子の直径はほとんどが100μm以下であり、当該酸化物粒子の50%粒子径は、1~20μmである。ビーズ径が大きいほど、略球状の酸化物粒子の間にある粒子径が小さい未燃カーボン粒子を粉砕するためには、硬い上記酸化物粒子を粉砕せねばならず、ビーズと粒子径の小さい未燃カーボン粒子が衝突する可能性は低くなる。ビーズ径が小さく、ビーズの曲率が大きくなるほど、粉砕工程(S5)において、ビーズは、硬い略球状の酸化物粒子と衝突せずに、粒子径の小さい未燃カーボン粒子と接触することができる。そのため、ビーズ径は1mm以下が好ましいといえる。
The bead diameter (hereinafter referred to as bead diameter) used in the grinding process by the bead mill is preferably 1 mm or less. The substantially spherical oxide particles are solid and hard and not easily crushed, but the unburned carbon particles are brittle and easily crushed. On the other hand, the diameter of the substantially spherical oxide particles is almost 100 μm or less, and the 50% particle diameter of the oxide particles is 1 to 20 μm. In order to pulverize unburned carbon particles having a smaller particle size between larger spherical oxide particles as the bead size is larger, the harder oxide particles must be pulverized. The possibility of collision of the fuel carbon particles is reduced. The smaller the bead diameter and the larger the curvature of the bead, the more the bead can come into contact with the unburned carbon particles having a small particle diameter without colliding with the hard substantially spherical oxide particles in the pulverization step (S5). Therefore, it can be said that the bead diameter is preferably 1 mm or less.
さらに、ビーズの密度は、3.5g/cm3以上であることが好ましい。ビーズの密度が3.5g/cm3以上である場合、ビーズが未燃カーボン粒子と衝突した際の破壊力が大きくなるため、未燃カーボン粒子を粉砕するためにかかる時間を短縮でき、粉砕処理を効率化できる。ビーズの密度を3.5g/cm3以上とするには、ビーズの材質を、セラミック、金属などにすることが好ましい。
Furthermore, the density of the beads is preferably 3.5 g / cm 3 or more. When the density of the beads is 3.5 g / cm 3 or more, the destructive force when the beads collide with the unburned carbon particles increases, so the time taken to pulverize the unburned carbon particles can be shortened, and the pulverization process Can be made more efficient. In order to set the density of the beads to 3.5 g / cm 3 or more, the material of the beads is preferably made of ceramic, metal or the like.
[6.向流型多段連続プロセス]
次に、本発明の第3の実施形態に係る製造方法における分離回収方法について説明する。第3の実施形態に係る分離回収方法は、混合装置(ミキサー)による混合工程と分離装置(セトラー)による比重分離工程との組合せを複数段階繰り返す向流型多段連続プロセスを採用している。例えば粗分離工程(S21)に多段連続プロセスを採用する場合、酸化物粒子を含む水相と、未燃カーボン粒子を含む溶剤相とが、多段階の粗分離工程(S21)で分離される。このため、第1の実施形態に係る単段連続プロセスと比べて、酸化物粒子と未燃カーボン粒子の分離効率をさらに向上し、回収される固形物中に含まれる酸化物粒子と未燃カーボン粒子の含有率をそれぞれ増加できる。水洗浄工程(S22)に多段連続プロセスを採用する場合も同様である。 [6. Counterflow type multistage continuous process]
Next, a separation and recovery method in the manufacturing method according to the third embodiment of the present invention will be described. The separation and recovery method according to the third embodiment employs a countercurrent multi-stage continuous process in which a combination of a mixing step by a mixing device (mixer) and a specific gravity separation step by a separation device (settler) is repeated in multiple stages. For example, when a multistage continuous process is employed in the coarse separation step (S21), the aqueous phase containing oxide particles and the solvent phase containing unburned carbon particles are separated in the multistage coarse separation step (S21). For this reason, compared with the single-stage continuous process according to the first embodiment, the separation efficiency of oxide particles and unburned carbon particles is further improved, and the oxide particles and unburned carbon contained in the recovered solid matter. The content of particles can be increased. The same applies when a multi-stage continuous process is employed in the water washing step (S22).
次に、本発明の第3の実施形態に係る製造方法における分離回収方法について説明する。第3の実施形態に係る分離回収方法は、混合装置(ミキサー)による混合工程と分離装置(セトラー)による比重分離工程との組合せを複数段階繰り返す向流型多段連続プロセスを採用している。例えば粗分離工程(S21)に多段連続プロセスを採用する場合、酸化物粒子を含む水相と、未燃カーボン粒子を含む溶剤相とが、多段階の粗分離工程(S21)で分離される。このため、第1の実施形態に係る単段連続プロセスと比べて、酸化物粒子と未燃カーボン粒子の分離効率をさらに向上し、回収される固形物中に含まれる酸化物粒子と未燃カーボン粒子の含有率をそれぞれ増加できる。水洗浄工程(S22)に多段連続プロセスを採用する場合も同様である。 [6. Counterflow type multistage continuous process]
Next, a separation and recovery method in the manufacturing method according to the third embodiment of the present invention will be described. The separation and recovery method according to the third embodiment employs a countercurrent multi-stage continuous process in which a combination of a mixing step by a mixing device (mixer) and a specific gravity separation step by a separation device (settler) is repeated in multiple stages. For example, when a multistage continuous process is employed in the coarse separation step (S21), the aqueous phase containing oxide particles and the solvent phase containing unburned carbon particles are separated in the multistage coarse separation step (S21). For this reason, compared with the single-stage continuous process according to the first embodiment, the separation efficiency of oxide particles and unburned carbon particles is further improved, and the oxide particles and unburned carbon contained in the recovered solid matter. The content of particles can be increased. The same applies when a multi-stage continuous process is employed in the water washing step (S22).
図11に示す例では、粗分離工程(S21)と水洗浄工程(S22)をともに複数段階繰り返す。粗分離工程(S21)をN段階(Nは2以上の整数)繰り返すとともに、水洗浄工程(S22)をM段階(Mは2以上の整数)繰り返す。
In the example shown in FIG. 11, both the rough separation step (S21) and the water washing step (S22) are repeated in multiple stages. The coarse separation step (S21) is repeated N steps (N is an integer of 2 or more), and the water washing step (S22) is repeated M steps (M is an integer of 2 or more).
例えば粗分離工程(S21)についてみると、Nが3以上の整数である場合、n段目(nは1以上、N-2以下の整数)の比重分離工程で分離された酸化物粒子P1及び残存した未燃カーボン粒子P2を含む水相ph1と、n+2段目の比重分離工程で分離された未燃カーボン粒子P2及び残存した酸化物粒子P1を含む溶剤相ph2とが、n+1段目の混合工程で混合され、スラリー化される。次いで、当該n+1段目の比重分離工程にて、酸化物粒子P1を主に含む水相ph1と、未燃カーボン粒子P2を主に含む溶剤相ph2とに分離される。かかる混合工程及び比重分離工程の組合せを、各段で繰り返すことで、1段目からN段目に向かうほど、酸化物粒子P1の含有率の高い水相ph1が得られる一方、N段目から1段目に向かうほど、未燃カーボン粒子P2の含有率の高い溶剤相ph2が得られる。水洗浄工程(S22)についても、粗分離工程(S21)と同様である。1段目からM段目に向かうほど、未燃カーボン粒子P2の含有率の高い溶剤相ph2が得られる一方、M段目から1段目に向かうほど、酸化物粒子P1の含有率の高い水相ph1が得られる。
For example, in the rough separation step (S21), when N is an integer of 3 or more, the oxide particles P1 separated in the specific gravity separation step of the n-th stage (n is an integer of 1 or more and N-2 or less) and The aqueous phase ph1 containing the remaining unburned carbon particles P2 and the solvent phase ph2 containing the unburned carbon particles P2 separated in the n + 2 stage specific gravity separation step and the remaining oxide particles P1 are mixed in the n + 1 stage. It is mixed and slurried in the process. Next, in the specific gravity separation step of the (n + 1) th stage, the water phase ph1 mainly containing oxide particles P1 and the solvent phase ph2 mainly containing unburned carbon particles P2 are separated. By repeating the combination of the mixing step and the specific gravity separation step at each stage, an aqueous phase ph1 having a higher content of oxide particles P1 is obtained from the first stage to the N stage, while from the N stage. The solvent phase ph2 having a higher content of unburned carbon particles P2 is obtained as it goes to the first stage. The water washing step (S22) is the same as the rough separation step (S21). The solvent phase ph2 having a higher content of unburned carbon particles P2 is obtained from the first stage to the M stage, while water having a higher content of oxide particles P1 is obtained from the M stage to the first stage. Phase ph1 is obtained.
N段目の混合工程で疎水性溶剤L2が投入される。その後、N段目の後段の第1回収工程(S3)では、酸化物粒子P1の含有率の高い水相ph1から、酸化物粒子P1と水L1がそれぞれ分離及び回収される。回収された水L1は、M段目の混合工程に戻されて再利用される。一方、M段目の混合工程で水L1が投入される。その後、M段目の後段の第2回収工程(S4)では、未燃カーボン粒子P2の含有率の高い溶剤相ph2から、未燃カーボン粒子P2と疎水性溶剤L2がそれぞれ分離及び回収される。回収された疎水性溶剤L2は、N段目の混合工程に戻されて再利用される。
* Hydrophobic solvent L2 is charged in the N-th mixing step. Thereafter, in the first recovery step (S3) in the latter stage of the Nth stage, the oxide particles P1 and the water L1 are separated and recovered from the aqueous phase ph1 having a high content of the oxide particles P1. The recovered water L1 is returned to the M-th mixing step and reused. On the other hand, water L1 is charged in the M-th mixing step. Thereafter, in the second recovery step (S4) in the latter stage of the Mth stage, the unburned carbon particles P2 and the hydrophobic solvent L2 are separated and recovered from the solvent phase ph2 having a high content of the unburned carbon particles P2. The recovered hydrophobic solvent L2 is returned to the N-th mixing step and reused.
なお、図11の例では、フライアッシュFAを1段目の混合工程で投入しているが、他の段目の混合工程でフライアッシュFAを投入してもよい。また、粗分離工程(S21)と水洗浄工程(S22)のいずれか一方が単段階、言い換えるとM又はNが1であってもよい。また、図7~10に示す工程例に倣い、いずれかの段階の粗分離工程(S21)又は水洗浄工程(S22)の前又は後に粉砕工程(S5)を追加してもよい。
In the example of FIG. 11, fly ash FA is introduced in the first stage mixing step, but fly ash FA may be introduced in the other stage mixing step. Further, one of the rough separation step (S21) and the water washing step (S22) may be a single step, in other words, M or N may be 1. Further, following the process example shown in FIGS. 7 to 10, a grinding step (S5) may be added before or after the rough separation step (S21) or the water washing step (S22) at any stage.
[7.炭素含有粉の利用方法]
次に、上記製造方法により製造された本実施形態に係る炭素含有粉の利用方法について説明する。 [7. How to use carbon-containing powder]
Next, the utilization method of the carbon containing powder which concerns on this embodiment manufactured with the said manufacturing method is demonstrated.
次に、上記製造方法により製造された本実施形態に係る炭素含有粉の利用方法について説明する。 [7. How to use carbon-containing powder]
Next, the utilization method of the carbon containing powder which concerns on this embodiment manufactured with the said manufacturing method is demonstrated.
上述したように、本実施形態に係る炭素含有粉の炭素含有率は、少なくとも50質量%以上、好ましくは70質量%以上と、非常に高い。従って、該炭素含有粉の燃焼時に、燃焼効率を高めることができる。さらに、炭素含有粉のN/C比は、0.02以下であり、非常に低く、窒素含有率が低い。従って、当該炭素含有粉の燃焼時に、窒素酸化物(NOx)の発生を抑制することができる。
As described above, the carbon content of the carbon-containing powder according to the present embodiment is very high, at least 50% by mass, preferably 70% by mass or more. Accordingly, the combustion efficiency can be increased during the combustion of the carbon-containing powder. Further, the N / C ratio of the carbon-containing powder is 0.02 or less, very low, and the nitrogen content is low. Therefore, generation of nitrogen oxides (NOx) can be suppressed during combustion of the carbon-containing powder.
よって、本実施形態に係る炭素含有粉は、焼結機、発電所等の燃焼炉、転炉等で使用される窒素含有率の低い石炭(すなわち低窒素炭)の代替として、有効利用することができ、産業上非常に有益である。
Therefore, the carbon-containing powder according to the present embodiment should be effectively used as an alternative to low-nitrogen coal (ie, low nitrogen coal) used in sintering machines, combustion furnaces such as power plants, converters, etc. Can be very useful in industry.
さらに、本実施形態に係る炭素含有粉は、多孔質粒子である未燃カーボン粒子を多く含有し、その比表面積は、活性コークス粉と同等の50~300m2/gであり、フライアッシュの比表面積(0.5~10m2/g)よりも、数十倍~百倍程度も大きい。従って、本実施形態に係る炭素含有粉は、SO2吸着能及び脱硝能を有しており、SO2吸着材や脱硝材として有効利用することができる。特に、上記第2の実施形態のように粉砕処理を施した場合には、炭素含有粉の比表面積がより大きくなるので、高品質のSO2吸着材や脱硝材として有効利用できる。
Furthermore, the carbon-containing powder according to the present embodiment contains a large amount of unburned carbon particles that are porous particles, and the specific surface area is 50 to 300 m 2 / g, which is the same as that of activated coke powder. It is several tens to hundred times larger than the surface area (0.5 to 10 m 2 / g). Therefore, the carbon-containing powder according to the present embodiment has SO 2 adsorption capacity and denitration capacity, and can be effectively used as an SO 2 adsorption material and denitration material. In particular, when the pulverization treatment is performed as in the second embodiment, the specific surface area of the carbon-containing powder becomes larger, and therefore, it can be effectively used as a high-quality SO 2 adsorbent or denitration material.
また、本実施形態に係る炭素含有粉のハンドリング性を高める観点から、当該炭素含有粉と他の粉体(例えば、スケール、コークス粉等)とを混練し、炭素含有粉の嵩比重を大きくした後に、上記各種の用途に利用することが好ましい。炭素含有粉は、多孔質材料であり、その嵩比重が小さく、かつ、粒子径が小さいので、単独では、非常に扱いにくい微粒子である。そこで、炭素含有粉を他の嵩比重の大きい粉体材料と混合して、嵩比重を大きくする(例えば、1g/cm3以上)ことが好ましい。これにより、粉塵の発生を抑制でき、ハンドリングし易くなるという利点がある。
In addition, from the viewpoint of improving the handling properties of the carbon-containing powder according to the present embodiment, the carbon-containing powder and other powders (for example, scale, coke powder, etc.) are kneaded to increase the bulk specific gravity of the carbon-containing powder. Later, it is preferably used for the various applications described above. Carbon-containing powder is a porous material, its bulk specific gravity is small, and its particle diameter is small, so it is a very difficult particle to handle by itself. Therefore, it is preferable to increase the bulk specific gravity (for example, 1 g / cm 3 or more) by mixing the carbon-containing powder with another powder material having a large bulk specific gravity. Thereby, generation | occurrence | production of dust can be suppressed and there exists an advantage that it becomes easy to handle.
以下、本発明の実施例について詳細に説明するが、本発明はこれら実施例に限定されるものではない。
Hereinafter, examples of the present invention will be described in detail, but the present invention is not limited to these examples.
[実施例1]
まず、表3を参照して実施例1の試験について説明する。表3は、本実施例1の試験条件と結果を示す。 [Example 1]
First, the test of Example 1 will be described with reference to Table 3. Table 3 shows the test conditions and results of Example 1.
まず、表3を参照して実施例1の試験について説明する。表3は、本実施例1の試験条件と結果を示す。 [Example 1]
First, the test of Example 1 will be described with reference to Table 3. Table 3 shows the test conditions and results of Example 1.
栓付の100mlメスシリンダー内に、水(L1)80mlと各種の疎水性液体(L2)20mlを入れた後、水相中のスラリー濃度CS[質量%]が表3に記載の濃度になるように、混合物(P1+P2)を投入した。混合物(P1+P2)としてフライアッシュを使用した。次いで、メスシリンダー内の混合液を手で激しく10秒間混合した後、10秒間静置した。その後、すぐに水相の部分からサンプルを採取し、水相中の固形物を回収し、回収した固形物の含有率を測定した。また、当該回収した固形物中の未燃カーボン粒子の含有率CBを測定した。また、以下の式(4)で表される未燃カーボン粒子分離率KAを算出した。一方、酸化物粒子回収率KBを、以下の式(5)で算出した。
After putting 80 ml of water (L1) and 20 ml of various hydrophobic liquids (L2) into a 100 ml graduated cylinder with a stopper, the slurry concentration C S [mass%] in the aqueous phase becomes the concentration shown in Table 3. As such, the mixture (P1 + P2) was charged. Fly ash was used as a mixture (P1 + P2). Next, the mixed solution in the graduated cylinder was vigorously mixed by hand for 10 seconds and then allowed to stand for 10 seconds. Thereafter, a sample was immediately taken from the aqueous phase portion, the solid in the aqueous phase was recovered, and the content of the recovered solid was measured. Was also measured content C B of unburned carbon particles solids in that the recovered. Moreover, to calculate the unburned carbon particles separation rate K A represented by the following formula (4). On the other hand, the oxide particles recovery K B, is calculated by the following equation (5).
KA[質量%]={(mA-mB)/mA}×100 ・・・(4)
KB[質量%]=(mP/mQ)×100 ・・・(5)
mA[g] :投入した未燃カーボン粒子の質量
mB[g] :水相に含まれる未燃カーボン粒子の質量
mQ[g] :投入した酸化物粒子の質量
mP[g] :水相に含まれる酸化物粒子の質量 K A [mass%] = {(m A −m B ) / m A } × 100 (4)
K B [mass%] = (m P / m Q ) × 100 (5)
m A [g]: Mass of unburned carbon particles charged m B [g]: Mass of unburned carbon particles contained in the aqueous phase m Q [g]: Mass of charged oxide particles m P [g]: Mass of oxide particles in the aqueous phase
KB[質量%]=(mP/mQ)×100 ・・・(5)
mA[g] :投入した未燃カーボン粒子の質量
mB[g] :水相に含まれる未燃カーボン粒子の質量
mQ[g] :投入した酸化物粒子の質量
mP[g] :水相に含まれる酸化物粒子の質量 K A [mass%] = {(m A −m B ) / m A } × 100 (4)
K B [mass%] = (m P / m Q ) × 100 (5)
m A [g]: Mass of unburned carbon particles charged m B [g]: Mass of unburned carbon particles contained in the aqueous phase m Q [g]: Mass of charged oxide particles m P [g]: Mass of oxide particles in the aqueous phase
また、表3に示すように、比較例1及び実施例1-1~1-9において分離対象である混合物(P1+P2)として使用したフライアッシュ中の未燃カーボン粒子の含有率CCは1.9質量%であり、当該フライアッシュの体積基準の50%粒子径は19μmであった。実施例1-10~1-13のフライアッシュ中における未燃カーボン粒子の含有率CCは5.3質量%であり、当該フライアッシュの体積基準の50%粒子径は21μmであった。
Further, as shown in Table 3, the content C C of unburned carbon particles in fly ash used as a mixture is separated target in Comparative Example 1 and Examples 1-1 ~ 1-9 (P1 + P2) 1. The volume-based 50% particle size of the fly ash was 19 μm. Content C C of unburned carbon particles in fly ash Examples 1-10 to 1-13 was 5.3 wt%, the 50% particle diameter on a volume basis of the fly ash was 21 [mu] m.
以上の試験の結果、表3に示すように、酸化物粒子回収率KBは、実施例1-1~1-13のいずれも73質量%以上であり、特に実施例1-1と1-6以外の実施例では、92質量%以上であった。従って、本実施形態に係る分離方法により、混合物(P1+P2)から酸化物粒子P1を高い回収率で回収できることが分かる。未燃カーボン粒子分離率KAは、実施例1-1~1-13において、42~56質量%であった。従って、本実施形態に係る分離方法により、回収された酸化物粒子P1中に含まれる未燃カーボン粒子P2の含有率を大幅に低減でき、含有率の高い高品質の酸化物粒子P1を回収できることが確認された。
Results of the above test, as shown in Table 3, the oxide particles recovery K B, and the Examples 1-1 to both 73 wt% or more of 1-13, in particular that of Example 1-1 1- In Examples other than 6, it was 92 mass% or more. Therefore, it can be seen that the oxide particles P1 can be recovered from the mixture (P1 + P2) at a high recovery rate by the separation method according to the present embodiment. Unburned carbon particles separation rate K A, in Examples 1-1 to 1-13 was 42 to 56% by weight. Therefore, by the separation method according to the present embodiment, the content of unburned carbon particles P2 contained in the recovered oxide particles P1 can be greatly reduced, and high-quality oxide particles P1 having a high content can be recovered. Was confirmed.
水相から回収した固形物中の未燃カーボン粒子の含有率CBは、疎水性液体L2としてのシリコーンオイルの比重が1.07である実施例1-1では、1.2質量%であった。一方、シリコーンオイルの比重が1.03である比較例1では、含有率CBは、1.9質量%であった。従って、疎水性液体L2の比重を1.05超とすることにより、比重分離速度を向上できることが分かる。すなわち、比較例1では、シリコーンオイルの比重が1.05以下であるため、水相の比重と疎水性液体相の比重が近く、相の分離速度が非常に遅い。比較例1において、上記混合後、1分間静置したが、相の分離はほとんど進行しなかった。そこで、メスシリンダー上部の約20mlを採取し、固形物を回収し、回収物中の未燃カーボン粒子の含有率CBを測定したところ、1.9%質量%であった。すなわち、投入したフライアッシュ中の未燃カーボン粒子の含有率CCからほとんど変化がなかった。
The content C B of unburned carbon particles in the solid recovered from the aqueous phase was 1.2% by mass in Example 1-1 where the specific gravity of the silicone oil as the hydrophobic liquid L2 was 1.07. It was. On the other hand, in Comparative Example 1 the specific gravity of the silicone oil is 1.03, and the content C B was 1.9 wt%. Therefore, it can be seen that the specific gravity separation rate can be improved by setting the specific gravity of the hydrophobic liquid L2 to more than 1.05. That is, in Comparative Example 1, since the specific gravity of the silicone oil is 1.05 or less, the specific gravity of the aqueous phase is close to the specific gravity of the hydrophobic liquid phase, and the phase separation rate is very slow. In Comparative Example 1, the mixture was allowed to stand for 1 minute after the above mixing, but the phase separation hardly proceeded. Therefore, taken approximately 20ml of the graduated cylinder top, the solid was collected, was measured content C B of unburned carbon particles in the recovered product was 1.9% by mass%. In other words, there was little change from content C C of unburned carbon particles in fly ash was charged.
なお、水相中のスラリー濃度CSを変化させた実施例1-2~1-6を比較すると、スラリー濃度CSが38質量%以上になると、水相から回収した固形物中の未燃カーボン粒子の含有率CBは大きくなった。特にスラリー濃度CSが47質量%の場合(実施例1-6)、含有率CBは1.7質量%となった。元のフライアッシュ中の未燃カーボン粒子の含有率(1.9質量%)と比較して、わずかに低下したにすぎない。これは、水相中のスラリー濃度CSを高くしすぎたことにより、水相と溶剤相との界面が不明確となり、よって、水相から回収した固形物中の未燃カーボン粒子の含有率CBが、あまり低下しなかったことを表していると推測される。
Incidentally, when comparing Examples 1-2 to 1-6 that the slurry concentration C S was varied in the aqueous phase, the slurry concentration C S is equal to or greater than 38 wt%, unburned solid which had been recovered from the aqueous phase the content of the carbon particles C B is increased. Particularly in the case of 47 wt% slurry concentration C S (Example 1-6), the content C B became 1.7 mass%. Compared to the content of unburned carbon particles in the original fly ash (1.9% by mass), it is only slightly reduced. This is because it has too high slurry concentration C S in the aqueous phase, the interface between the aqueous phase and the solvent phase is unclear, therefore, the content of unburned carbon particles solids which had been recovered from the aqueous phase C B is presumed to represent that it did not so much lowered.
[実施例2]
実施例2では、疎水性溶剤としてトリクロロエチレンを使用し、図5に示す分離回収方法に基づいて、フライアッシュ(以下、単にFAと称する。)から炭素含有粉を回収した。 [Example 2]
In Example 2, trichloroethylene was used as a hydrophobic solvent, and carbon-containing powder was recovered from fly ash (hereinafter simply referred to as FA) based on the separation and recovery method shown in FIG.
実施例2では、疎水性溶剤としてトリクロロエチレンを使用し、図5に示す分離回収方法に基づいて、フライアッシュ(以下、単にFAと称する。)から炭素含有粉を回収した。 [Example 2]
In Example 2, trichloroethylene was used as a hydrophobic solvent, and carbon-containing powder was recovered from fly ash (hereinafter simply referred to as FA) based on the separation and recovery method shown in FIG.
具体的には、密閉容器(分液ロート)に、水とトリクロロエチレン(比重:1.46)を250mlずつ投入し、FA(炭素含有率:9.3質量%)を35g投入した。密閉容器(分液ロート)を手で激しく30秒間振って、FAと水とトリクロロエチレンをよく混合した。混合後、密閉容器(分液ロート)を10秒間静置し、未燃カーボンが濃縮しているトリクロロエチレン相を回収し、別の密閉容器(分液ロート)に投入した(粗分離工程S21)。また、トリクロロエチレン相と水相の界面付近のサンプルは廃棄した後、酸化物が濃縮している水相を回収し、ろ過後、固形物を乾燥し回収した。回収したトリクロロエチレン相に水を250ml加え、密閉容器(分液ロート)を手で激しく30秒間振って、トリクロロエチレン相と水を混合した。その後、密閉容器(分液ロート)を10秒間静置し、再度、未燃カーボンが濃縮しているトリクロロエチレン相を回収した(水洗浄工程S22)。この際、トリクロロエチレン相と水相の界面付近のサンプルは回収せず廃棄した。この水洗浄工程S22を3回繰り返し、未燃カーボンが濃縮しているトリクロロエチレン相を回収した。回収したトリクロロエチレン相をろ過後(固液分離工程S41)、乾燥により水分とトリクロロエチレンを揮発させ(乾燥工程S42)、炭素含有粉を得た。
Specifically, 250 ml each of water and trichlorethylene (specific gravity: 1.46) were added to an airtight container (separation funnel), and 35 g of FA (carbon content: 9.3 mass%) was added. The sealed container (separation funnel) was vigorously shaken by hand for 30 seconds to thoroughly mix FA, water and trichlorethylene. After mixing, the sealed container (separation funnel) was allowed to stand for 10 seconds, and the trichlorethylene phase in which the unburned carbon was concentrated was collected and put into another sealed container (separation funnel) (coarse separation step S21). Further, after discarding the sample near the interface between the trichlorethylene phase and the aqueous phase, the aqueous phase in which the oxide was concentrated was recovered, and after filtration, the solid was dried and recovered. 250 ml of water was added to the recovered trichlorethylene phase, and the sealed container (separation funnel) was vigorously shaken by hand for 30 seconds to mix the trichlorethylene phase and water. Thereafter, the sealed container (separation funnel) was allowed to stand for 10 seconds, and the trichlorethylene phase in which unburned carbon was concentrated was collected again (water washing step S22). At this time, the sample near the interface between the trichlorethylene phase and the aqueous phase was not recovered and discarded. This water washing step S22 was repeated three times to recover the trichlorethylene phase in which unburned carbon was concentrated. After filtering the collected trichlorethylene phase (solid-liquid separation step S41), water and trichlorethylene were volatilized by drying (drying step S42) to obtain a carbon-containing powder.
この結果、実施例2の炭素含有粉の炭素含有率は、57質量%であり、炭素含有粉中の窒素含有率と炭素含有率との比であるN/C比(質量比)は、0.0072であった。また、炭素含有粉中の酸化物粒子中のSiO2成分とAl2O3成分の合計は75質量%以上であった。また、水相から回収した固形物中の炭素含有率は2.8質量%であり、処理前のFA中の炭素含有率と比較して、低下していることを確認した。
As a result, the carbon content of the carbon-containing powder of Example 2 is 57% by mass, and the N / C ratio (mass ratio), which is the ratio between the nitrogen content and the carbon content in the carbon-containing powder, is 0. .0072. The total SiO 2 component and Al 2 O 3 component in the oxide particles in the carbon-containing powder was not less than 75 mass%. Moreover, the carbon content rate in the solid substance collect | recovered from the water phase was 2.8 mass%, and it was confirmed that it has fallen compared with the carbon content rate in FA before a process.
[比較例2]
比較例2では、上記特許文献1の実施例1に記載の浮選方法に基づいて、FAから炭素含有粉を回収した。 [Comparative Example 2]
In Comparative Example 2, carbon-containing powder was recovered from FA based on the flotation method described in Example 1 of Patent Document 1.
比較例2では、上記特許文献1の実施例1に記載の浮選方法に基づいて、FAから炭素含有粉を回収した。 [Comparative Example 2]
In Comparative Example 2, carbon-containing powder was recovered from FA based on the flotation method described in Example 1 of Patent Document 1.
具体的には、水1000mlと、FA(未燃カーボン分、9.3質量%)200gとを攪拌しながら混合し、スラリーとした。このスラリーを、高速剪断ミキサーで高速攪拌(高速剪断ミキサー動力:80Kw/m3)することにより、スラリーに剪断力を付与した。その後、スラリーを低速で攪拌しながら、捕集剤として灯油を1.3ml添加し、起泡剤としてMIBC(メチルイソブチルカルビノール)を200mg添加した。次に、浮選処理により気泡を発生させ、発生した気泡に未燃カーボンを付着させて浮上させ、浮上した気泡をフロスとして取り出した。この浮選工程を5分継続して行った。
Specifically, 1000 ml of water and 200 g of FA (unburned carbon content, 9.3 mass%) were mixed with stirring to form a slurry. The slurry was subjected to high-speed stirring with a high-speed shear mixer (high-speed shear mixer power: 80 Kw / m 3 ) to apply a shearing force to the slurry. Thereafter, while stirring the slurry at a low speed, 1.3 ml of kerosene was added as a collecting agent, and 200 mg of MIBC (methyl isobutyl carbinol) was added as a foaming agent. Next, bubbles were generated by flotation treatment, unburned carbon was attached to the generated bubbles and floated, and the lifted bubbles were taken out as floss. This flotation process was continued for 5 minutes.
次に、容器内に残ったFA(テール)を乾燥して計量したところ、152gあり、その中の炭素含有率は3.3質量%であった。また、浮上した炭素濃縮物を乾燥させた後、付着している灯油、起泡剤を除去するため、n-ヘキサンで洗浄し、乾燥させた後、成分分析を行った。
Next, when the FA (tail) remaining in the container was dried and weighed, there were 152 g, and the carbon content therein was 3.3% by mass. In addition, after the floated carbon concentrate was dried, in order to remove the kerosene and the foaming agent adhering, it was washed with n-hexane and dried, and then component analysis was performed.
この結果、比較例2の炭素濃縮物の炭素含有率は、34質量%であり、N/C比は、0.0095であった。
As a result, the carbon content of the carbon concentrate of Comparative Example 2 was 34% by mass, and the N / C ratio was 0.0095.
[実施例3]
実施例3では、比較例2で得られた炭素濃縮物(炭素含有率:34質量%)を、実施例2と同様な方法で処理し、炭素含有粉を得た。この結果、実施例3の炭素含有粉の炭素含有率は、56質量%であり、N/C比は、0.0074であった。また、炭素含有粉中の酸化物粒子中のSiO2成分とAl2O3成分の合計は75質量%以上であった。 [Example 3]
In Example 3, the carbon concentrate obtained in Comparative Example 2 (carbon content: 34% by mass) was treated in the same manner as in Example 2 to obtain a carbon-containing powder. As a result, the carbon content of the carbon-containing powder of Example 3 was 56% by mass, and the N / C ratio was 0.0074. The total SiO 2 component and Al 2 O 3 component in the oxide particles in the carbon-containing powder was not less than 75 mass%.
実施例3では、比較例2で得られた炭素濃縮物(炭素含有率:34質量%)を、実施例2と同様な方法で処理し、炭素含有粉を得た。この結果、実施例3の炭素含有粉の炭素含有率は、56質量%であり、N/C比は、0.0074であった。また、炭素含有粉中の酸化物粒子中のSiO2成分とAl2O3成分の合計は75質量%以上であった。 [Example 3]
In Example 3, the carbon concentrate obtained in Comparative Example 2 (carbon content: 34% by mass) was treated in the same manner as in Example 2 to obtain a carbon-containing powder. As a result, the carbon content of the carbon-containing powder of Example 3 was 56% by mass, and the N / C ratio was 0.0074. The total SiO 2 component and Al 2 O 3 component in the oxide particles in the carbon-containing powder was not less than 75 mass%.
[実施例4]
実施例4では、疎水性溶剤として1-ブロモプロパンを使用し、図7に示す分離回収方法に基づいて、FAから炭素含有粉を回収した。 [Example 4]
In Example 4, 1-bromopropane was used as a hydrophobic solvent, and carbon-containing powder was recovered from FA based on the separation and recovery method shown in FIG.
実施例4では、疎水性溶剤として1-ブロモプロパンを使用し、図7に示す分離回収方法に基づいて、FAから炭素含有粉を回収した。 [Example 4]
In Example 4, 1-bromopropane was used as a hydrophobic solvent, and carbon-containing powder was recovered from FA based on the separation and recovery method shown in FIG.
具体的には、容器に、水と1-ブロモプロパン(比重:1.35)を250mlずつ投入し、FA(炭素含有率:9.3質量%)を35g投入した。その後、容器内をスターラーで低速で撹拌しながら、超音波発振機により混合液に対して超音波処理を施すことにより、混合液中の粒子を粉砕する処理を行った(粉砕工程S5)。このとき、5,250kJ/m3のエネルギー量の超音波を3分間付与した。粉砕処理の後、混合液を密閉容器(分液ロート)に移し、密閉容器(分液ロート)を手で激しく30秒間振って、FAと水と1-ブロモプロパンをよく混合した。混合後、密閉容器(分液ロート)を10秒間静置し、未燃カーボンが濃縮している1-ブロモプロパン相を回収し、水相を廃棄した(粗分離工程S21)。また、1-ブロモプロパン相と水相の界面付近のサンプルは廃棄した後、酸化物が濃縮している水相を回収し、ろ過後、固形物を乾燥し回収した。回収した1-ブロモプロパン相を密閉容器(分液ロート)に入れ、水を250ml加え、密閉容器(分液ロート)を手で激しく30秒間振って、1-ブロモプロパン相と水を混合した。その後、密閉容器(分液ロート)を10秒間静置し、再度、未燃カーボンが濃縮している1-ブロモプロパン相を回収した(水洗浄工程S22)。この際、1-ブロモプロパン相と水相の界面付近のサンプルは回収せず廃棄した。この水洗浄工程S22を3回繰り返し、未燃カーボンが濃縮している1-ブロモプロパン相を回収した。回収した1-ブロモプロパン相をろ過後(固液分離工程S41)、乾燥により水分と1-ブロモプロパンを揮発させ(乾燥工程S42)、炭素含有粉を得た。
Specifically, 250 ml each of water and 1-bromopropane (specific gravity: 1.35) were charged into a container, and 35 g of FA (carbon content: 9.3 mass%) was charged. Thereafter, while the inside of the container was stirred at a low speed with a stirrer, the mixture was subjected to ultrasonic treatment with an ultrasonic oscillator to pulverize the particles in the mixture (pulverization step S5). At this time, an ultrasonic wave having an energy amount of 5,250 kJ / m 3 was applied for 3 minutes. After the pulverization treatment, the mixed solution was transferred to a sealed container (separation funnel), and the sealed container (separation funnel) was vigorously shaken by hand for 30 seconds to thoroughly mix FA, water, and 1-bromopropane. After mixing, the sealed container (separation funnel) was allowed to stand for 10 seconds, the 1-bromopropane phase in which unburned carbon was concentrated was recovered, and the aqueous phase was discarded (coarse separation step S21). Further, after discarding the sample near the interface between the 1-bromopropane phase and the aqueous phase, the aqueous phase in which the oxide was concentrated was recovered, and after filtration, the solid was dried and recovered. The recovered 1-bromopropane phase was placed in a sealed container (separation funnel), 250 ml of water was added, and the sealed container (separation funnel) was shaken vigorously by hand for 30 seconds to mix the 1-bromopropane phase and water. Thereafter, the sealed container (separation funnel) was allowed to stand for 10 seconds, and the 1-bromopropane phase in which unburned carbon was concentrated was collected again (water washing step S22). At this time, the sample near the interface between the 1-bromopropane phase and the aqueous phase was not recovered and discarded. This water washing step S22 was repeated three times to recover the 1-bromopropane phase in which unburned carbon was concentrated. After filtering the collected 1-bromopropane phase (solid-liquid separation step S41), water and 1-bromopropane were volatilized by drying (drying step S42) to obtain a carbon-containing powder.
この結果、実施例4の炭素含有粉の炭素含有率は、82質量%であり、N/C比は、0.0061であった。また、炭素含有粉中の酸化物粒子中のSiO2成分とAl2O3成分の合計は75質量%以上であった。また、水相から回収した固形物中の炭素含有率は1.2質量%であり、処理前のFA中の炭素含有率と比較して低下し、かつ、実施例2で得た水相から回収した固形物中の炭素含有率と比較しても低下していることを確認した。
As a result, the carbon content of the carbon-containing powder of Example 4 was 82% by mass, and the N / C ratio was 0.0061. The total SiO 2 component and Al 2 O 3 component in the oxide particles in the carbon-containing powder was not less than 75 mass%. Further, the carbon content in the solid recovered from the aqueous phase is 1.2% by mass, which is lower than the carbon content in the FA before the treatment, and from the aqueous phase obtained in Example 2. It was confirmed that the carbon content in the recovered solid was also reduced.
[実施例5]
実施例5では、疎水性溶剤としてトリクロロエチレンを使用し、図8に示す分離回収方法に基づいて、FAから炭素含有粉を回収した。 [Example 5]
In Example 5, trichloroethylene was used as the hydrophobic solvent, and carbon-containing powder was recovered from FA based on the separation and recovery method shown in FIG.
実施例5では、疎水性溶剤としてトリクロロエチレンを使用し、図8に示す分離回収方法に基づいて、FAから炭素含有粉を回収した。 [Example 5]
In Example 5, trichloroethylene was used as the hydrophobic solvent, and carbon-containing powder was recovered from FA based on the separation and recovery method shown in FIG.
具体的には、容器に、水250mlを投入し、FA(炭素含有率:10.8質量%)を35g投入した。その後、容器内の混合液に対して高速せん断ミキサー(ホモジナイザー)による粉砕処理を3分間行った(粉砕工程S5)。粉砕処理の後、混合液を密閉容器(分液ロート)に移し、トリクロロエチレン(比重:1.46)250mlを加え、密閉容器(分液ロート)を手で激しく30秒間振って、FAと水とトリクロロエチレンをよく混合した。混合後、密閉容器(分液ロート)を10秒間静置し、未燃カーボンが濃縮しているトリクロロエチレン相を回収し、別の密閉容器(分液ロート)に投入した(粗分離工程S21)。また、トリクロロエチレン相と水相の界面付近のサンプルは廃棄した後、酸化物が濃縮している水相を回収し、ろ過後、固形物を乾燥し回収した。回収したトリクロロエチレン相に水を250ml加え、密閉容器(分液ロート)を手で激しく30秒間振って、トリクロロエチレン相と水を混合し、その後、密閉容器(分液ロート)を10秒間静置し、再度、未燃カーボンが濃縮しているトリクロロエチレン相を回収した(水洗浄工程S22)。この際、トリクロロエチレン相と水相の界面付近のサンプルは回収せず廃棄した。この水洗浄工程S22を3回繰り返し、未燃カーボンが濃縮しているトリクロロエチレン相を回収した。トリクロロエチレン相をろ過後(固液分離工程S41)、乾燥により水分とトリクロロエチレンを揮発させ(乾燥工程S42)、炭素含有粉を得た。
Specifically, 250 ml of water was charged into the container, and 35 g of FA (carbon content: 10.8% by mass) was charged. Thereafter, the mixed solution in the container was pulverized by a high-speed shear mixer (homogenizer) for 3 minutes (pulverization step S5). After the pulverization treatment, the mixed solution is transferred to a sealed container (separation funnel), 250 ml of trichlorethylene (specific gravity: 1.46) is added, and the sealed container (separation funnel) is shaken vigorously by hand for 30 seconds. Trichlorethylene was mixed well. After mixing, the sealed container (separation funnel) was allowed to stand for 10 seconds, and the trichlorethylene phase in which the unburned carbon was concentrated was collected and put into another sealed container (separation funnel) (coarse separation step S21). Further, after discarding the sample near the interface between the trichlorethylene phase and the aqueous phase, the aqueous phase in which the oxide was concentrated was recovered, and after filtration, the solid was dried and recovered. Add 250 ml of water to the recovered trichlorethylene phase, shake the sealed container (separation funnel) vigorously by hand for 30 seconds to mix the trichlorethylene phase and water, and then leave the sealed container (separation funnel) for 10 seconds, Again, the trichlorethylene phase in which unburned carbon was concentrated was recovered (water washing step S22). At this time, the sample near the interface between the trichlorethylene phase and the aqueous phase was not recovered and discarded. This water washing step S22 was repeated three times to recover the trichlorethylene phase in which unburned carbon was concentrated. After the trichlorethylene phase was filtered (solid-liquid separation step S41), moisture and trichlorethylene were volatilized by drying (drying step S42) to obtain a carbon-containing powder.
この結果、実施例5の炭素含有粉の炭素含有率は、87質量%であり、N/C比は、0.011であった。また、炭素含有粉中の酸化物粒子中のSiO2成分とAl2O3成分の合計は75質量%以上であった。また、水相から回収した固形物中の炭素含有率は1.4質量%であり、処理前のFA中の炭素含有率と比較して低下し、かつ、実施例2で得た水相から回収した固形物中の炭素含有率と比較しても低下していることを確認した。
As a result, the carbon content of the carbon-containing powder of Example 5 was 87% by mass, and the N / C ratio was 0.011. The total SiO 2 component and Al 2 O 3 component in the oxide particles in the carbon-containing powder was not less than 75 mass%. The carbon content in the solid recovered from the aqueous phase is 1.4% by mass, which is lower than the carbon content in the FA before the treatment, and from the aqueous phase obtained in Example 2. It was confirmed that the carbon content in the recovered solid was also reduced.
[実施例5-1]
実施例5-1では、疎水性溶剤としてトリクロロエチレンを使用し、図8に示す分離回収方法に基づいて、FAから炭素含有粉を回収した。 [Example 5-1]
In Example 5-1, trichloroethylene was used as a hydrophobic solvent, and carbon-containing powder was recovered from FA based on the separation and recovery method shown in FIG.
実施例5-1では、疎水性溶剤としてトリクロロエチレンを使用し、図8に示す分離回収方法に基づいて、FAから炭素含有粉を回収した。 [Example 5-1]
In Example 5-1, trichloroethylene was used as a hydrophobic solvent, and carbon-containing powder was recovered from FA based on the separation and recovery method shown in FIG.
具体的には、容器に、水250mlを投入し、FA(炭素含有率:9.3質量%)を35g投入した。その後、ジルコニアビーズ(密度:6.0g/cm3)を100g入れ、手で激しく30秒間振とうし、FAを粉砕した(粉砕工程S5)。使用したビーズの直径(以下、ビーズ径DB)を変化させ、100、200、300、500、800、1000、1500、2000、3000μmとした。粉砕処理後、容器を5秒間静置し、ジルコニアビーズを沈殿させた。容器内の上部の粉砕されたFAを含んだ水相を回収し、別の密閉容器(分液ロート)に移し、トリクロロエチレン(比重:1.46)250mlを加え、密閉容器(分液ロート)を手で激しく30秒間振って、FAと水とトリクロロエチレンをよく混合した。混合後、密閉容器(分液ロート)を10秒間静置し、未燃カーボンが濃縮しているトリクロロエチレン相を回収し、別の密閉容器(分液ロート)に投入した(粗分離工程S21)。この際、トリクロロエチレン相と水相の界面付近のサンプルは廃棄した。回収したトリクロロエチレン相に水を250ml加え、密閉容器(分液ロート)を手で激しく30秒間振って、トリクロロエチレン相と水を混合し、その後、密閉容器(分液ロート)を10秒間静置し、再度、未燃カーボンが濃縮しているトリクロロエチレン相を回収した(水洗浄工程S22)。この際、トリクロロエチレン相と水相の界面付近のサンプルは回収せず廃棄した。この水洗浄工程S22を3回繰り返し、未燃カーボンが濃縮しているトリクロロエチレン相を回収した。トリクロロエチレン相をろ過後(固液分離工程S41)、乾燥により水分とトリクロロエチレンを揮発させ(乾燥工程S42)、炭素含有粉を得た。
Specifically, 250 ml of water was charged into the container, and 35 g of FA (carbon content: 9.3 mass%) was charged. Thereafter, 100 g of zirconia beads (density: 6.0 g / cm 3 ) was added and shaken vigorously by hand for 30 seconds to pulverize FA (grinding step S5). The diameter of the used beads (hereinafter, bead diameter D B ) was changed to 100, 200, 300, 500, 800, 1000, 1500, 2000, and 3000 μm. After the pulverization treatment, the container was allowed to stand for 5 seconds to precipitate zirconia beads. The upper aqueous phase containing the pulverized FA in the container is collected, transferred to another sealed container (separation funnel), 250 ml of trichlorethylene (specific gravity: 1.46) is added, and the sealed container (separation funnel) is removed. Shake vigorously by hand for 30 seconds to mix FA, water and trichlorethylene well. After mixing, the sealed container (separation funnel) was allowed to stand for 10 seconds, and the trichlorethylene phase in which the unburned carbon was concentrated was collected and put into another sealed container (separation funnel) (coarse separation step S21). At this time, the sample near the interface between the trichlorethylene phase and the aqueous phase was discarded. Add 250 ml of water to the recovered trichlorethylene phase, shake the sealed container (separation funnel) vigorously by hand for 30 seconds to mix the trichlorethylene phase and water, and then leave the sealed container (separation funnel) for 10 seconds, Again, the trichlorethylene phase in which unburned carbon was concentrated was recovered (water washing step S22). At this time, the sample near the interface between the trichlorethylene phase and the aqueous phase was not recovered and discarded. This water washing step S22 was repeated three times to recover the trichlorethylene phase in which unburned carbon was concentrated. After the trichlorethylene phase was filtered (solid-liquid separation step S41), moisture and trichlorethylene were volatilized by drying (drying step S42) to obtain a carbon-containing powder.
この結果、図12に示すビーズ径DBと炭素含有粉の炭素含有率CAの関係が得られた。図12に示すように、ビーズ径DBが1000μm以下であれば、炭素含有粉中の炭素含有率CAが70%超となることが確認された。
As a result, the relationship between the carbon content C A of the bead diameter D B and the carbon-containing powder shown in FIG. 12 were obtained. As shown in FIG. 12, if the 1000μm or less bead diameter D B, it was confirmed that the carbon content C A in the carbon-containing powder is 70%.
[実施例6]
実施例6では、疎水性溶剤としてトリクロロエチレンを使用し、図9に示す分離回収方法に基づいて、FAから炭素含有粉を回収した。 [Example 6]
In Example 6, trichloroethylene was used as a hydrophobic solvent, and carbon-containing powder was recovered from FA based on the separation and recovery method shown in FIG.
実施例6では、疎水性溶剤としてトリクロロエチレンを使用し、図9に示す分離回収方法に基づいて、FAから炭素含有粉を回収した。 [Example 6]
In Example 6, trichloroethylene was used as a hydrophobic solvent, and carbon-containing powder was recovered from FA based on the separation and recovery method shown in FIG.
具体的には、密閉容器に、トリクロロエチレン(比重:1.46)250mlを投入し、FA(炭素含有率:9.3質量%)を35g投入した。その後、ジルコニアビーズ(100μmφ、密度6.0g/cm3)を100g入れ、手で激しく30秒間振とうし、FAを粉砕した(粉砕工程S5)。粉砕処理後、密閉容器を5秒間静置し、ジルコニアビーズを沈殿させた。密閉容器内の上部の粉砕されたFAを含んだトリクロロエチレン相を回収し、別の密閉容器(分液ロート)に移し、水250mlを加え、密閉容器(分液ロート)を手で激しく30秒間振って、FAと水とトリクロロエチレンをよく混合した。混合後、密閉容器(分液ロート)を10秒間静置し、未燃カーボンが濃縮しているトリクロロエチレン相を回収し、別の密閉容器(分液ロート)に投入した(粗分離工程S21)。また、トリクロロエチレン相と水相の界面付近のサンプルは廃棄した後、酸化物が濃縮している水相を回収し、ろ過後、固形物を乾燥し回収した。回収したトリクロロエチレン相に水を100ml加え、密閉容器(分液ロート)を手で激しく30秒間振って、トリクロロエチレン相と水を混合した。その後、密閉容器(分液ロート)を10秒間静置し、再度、未燃カーボンが濃縮しているトリクロロエチレン相を回収した(水洗浄工程S22)。この際、トリクロロエチレン相と水相の界面付近のサンプルは回収せず廃棄した。この水洗浄工程S22を3回繰り返し、未燃カーボンが濃縮しているトリクロロエチレン相を回収した。回収したトリクロロエチレン相をろ過後(固液分離工程S41)、乾燥により水分とトリクロロエチレンを揮発させ(乾燥工程S42)、炭素含有粉を得た。
Specifically, 250 ml of trichlorethylene (specific gravity: 1.46) was charged into an airtight container, and 35 g of FA (carbon content: 9.3 mass%) was charged. Thereafter, 100 g of zirconia beads (100 μmφ, density 6.0 g / cm 3 ) was added and shaken vigorously by hand for 30 seconds to pulverize FA (grinding step S5). After the pulverization treatment, the sealed container was allowed to stand for 5 seconds to precipitate zirconia beads. The trichlorethylene phase containing the pulverized FA in the upper part of the sealed container is collected, transferred to another sealed container (separation funnel), 250 ml of water is added, and the sealed container (separation funnel) is shaken vigorously by hand for 30 seconds. Then, FA, water, and trichlorethylene were mixed well. After mixing, the sealed container (separation funnel) was allowed to stand for 10 seconds, and the trichlorethylene phase in which the unburned carbon was concentrated was collected and put into another sealed container (separation funnel) (coarse separation step S21). Further, after discarding the sample near the interface between the trichlorethylene phase and the aqueous phase, the aqueous phase in which the oxide was concentrated was recovered, and after filtration, the solid was dried and recovered. 100 ml of water was added to the recovered trichlorethylene phase, and the sealed container (separation funnel) was shaken vigorously by hand for 30 seconds to mix the trichlorethylene phase and water. Thereafter, the sealed container (separation funnel) was allowed to stand for 10 seconds, and the trichlorethylene phase in which unburned carbon was concentrated was collected again (water washing step S22). At this time, the sample near the interface between the trichlorethylene phase and the aqueous phase was not recovered and discarded. This water washing step S22 was repeated three times to recover the trichlorethylene phase in which unburned carbon was concentrated. After filtering the collected trichlorethylene phase (solid-liquid separation step S41), water and trichlorethylene were volatilized by drying (drying step S42) to obtain a carbon-containing powder.
この結果、実施例6の炭素含有粉の炭素含有率は、85質量%であり、N/C比は、0.0068であった。また、炭素含有粉中の酸化物粒子中のSiO2成分とAl2O3成分の合計は75質量%以上であった。また、水相から回収した固形物中の炭素含有率は1.0質量%であり、処理前のFA中の炭素含有率と比較して低下し、かつ、実施例2で得た水相から回収した固形物中の炭素含有率と比較しても低下していることを確認した。
As a result, the carbon content of the carbon-containing powder of Example 6 was 85% by mass, and the N / C ratio was 0.0068. The total SiO 2 component and Al 2 O 3 component in the oxide particles in the carbon-containing powder was not less than 75 mass%. Further, the carbon content in the solid recovered from the aqueous phase is 1.0% by mass, which is lower than the carbon content in the FA before the treatment, and from the aqueous phase obtained in Example 2. It was confirmed that the carbon content in the recovered solid was also reduced.
[実施例7]
実施例7では、疎水性溶剤としてトリクロロエチレンを使用し、図10に示す分離回収方法に基づいて、FAから炭素含有粉を回収した。 [Example 7]
In Example 7, trichloroethylene was used as a hydrophobic solvent, and carbon-containing powder was recovered from FA based on the separation and recovery method shown in FIG.
実施例7では、疎水性溶剤としてトリクロロエチレンを使用し、図10に示す分離回収方法に基づいて、FAから炭素含有粉を回収した。 [Example 7]
In Example 7, trichloroethylene was used as a hydrophobic solvent, and carbon-containing powder was recovered from FA based on the separation and recovery method shown in FIG.
具体的には、密閉容器(分液ロート)に、水とトリクロロエチレン(比重:1.46)を250mlずつ投入し、FA(炭素含有率:9.3質量%)を35g投入した。密閉容器(分液ロート)を手で激しく30秒間振って、FAと水とトリクロロエチレンをよく混合した。混合後、密閉容器(分液ロート)を10秒間静置し、未燃カーボンが濃縮しているトリクロロエチレン相を回収し、別の容器に投入した(粗分離工程S21)。この際、トリクロロエチレン相と水相の界面付近のサンプルは廃棄した。その後、容器内をスターラーで低速で撹拌しながら、超音波発振機により混合液に対して超音波処理を施すことにより、混合液中の粒子を粉砕する処理を行った(粉砕工程S5)。このとき、5,250kJ/m3のエネルギー量の超音波を3分間付与した。粉砕処理後、密閉容器(分液ロート)に移し、密閉容器(分液ロート)内の混合液に水を250ml加え、密閉容器(分液ロート)を手で激しく30秒間振って、トリクロロエチレン相と水を混合した。その後、密閉容器(分液ロート)を10秒間静置し、再度、未燃カーボンが濃縮しているトリクロロエチレン相を回収した(水洗浄工程S22)。この際、トリクロロエチレン相と水相の界面付近のサンプルは回収せず廃棄した。この水洗浄工程S22を3回繰り返し、未燃カーボンが濃縮しているトリクロロエチレン相を回収した。回収したトリクロロエチレン相をろ過後(固液分離工程S41)、乾燥により水分とトリクロロエチレンを揮発させ(乾燥工程S42)、炭素含有粉を得た。
Specifically, 250 ml each of water and trichlorethylene (specific gravity: 1.46) were added to an airtight container (separation funnel), and 35 g of FA (carbon content: 9.3 mass%) was added. The sealed container (separation funnel) was vigorously shaken by hand for 30 seconds to thoroughly mix FA, water and trichlorethylene. After mixing, the sealed container (separation funnel) was allowed to stand for 10 seconds, and the trichlorethylene phase in which unburned carbon was concentrated was collected and put into another container (coarse separation step S21). At this time, the sample near the interface between the trichlorethylene phase and the aqueous phase was discarded. Thereafter, while the inside of the container was stirred at a low speed with a stirrer, the mixture was subjected to ultrasonic treatment with an ultrasonic oscillator to pulverize the particles in the mixture (pulverization step S5). At this time, an ultrasonic wave having an energy amount of 5,250 kJ / m 3 was applied for 3 minutes. After pulverization, transfer to a sealed container (separation funnel), add 250 ml of water to the mixture in the sealed container (separation funnel), shake the sealed container (separation funnel) vigorously by hand for 30 seconds, Water was mixed. Thereafter, the sealed container (separation funnel) was allowed to stand for 10 seconds, and the trichlorethylene phase in which unburned carbon was concentrated was collected again (water washing step S22). At this time, the sample near the interface between the trichlorethylene phase and the aqueous phase was not recovered and discarded. This water washing step S22 was repeated three times to recover the trichlorethylene phase in which unburned carbon was concentrated. After filtering the collected trichlorethylene phase (solid-liquid separation step S41), water and trichlorethylene were volatilized by drying (drying step S42) to obtain a carbon-containing powder.
この結果、実施例7の炭素含有粉の炭素含有率は、86質量%であり、N/C比は、0.0081であった。また、炭素含有粉中の酸化物粒子中のSiO2成分とAl2O3成分の合計は75質量%以上であった。
As a result, the carbon content of the carbon-containing powder of Example 7 was 86% by mass, and the N / C ratio was 0.0081. The total SiO 2 component and Al 2 O 3 component in the oxide particles in the carbon-containing powder was not less than 75 mass%.
以上の実施例2~5、6、7及び比較例2の結果を表4に示す。
Table 4 shows the results of Examples 2 to 5, 6, 7 and Comparative Example 2 described above.
表4に示すように、本発明の実施例2~7の炭素含有粉の炭素含有率は、56~87質量%であり、基準である50質量%以上を満たしている。特に、粉砕工程S5を伴う分離回収方法により製造された実施例4~7では、炭素含有率は、82質量%以上であり、より高い基準である70質量%以上を満たしている。これに対し、比較例2の炭素含有粉の炭素含有率は、34質量%と低く、基準である50質量%未満である。かかる結果によれば、本実施形態に係る製造方法における分離回収方法により、FAから未燃カーボン粒子を好適に分離して、炭素含有率が少なくとも50質量%以上の炭素含有粉を好適に得ることができるといえる。
As shown in Table 4, the carbon content of the carbon-containing powders of Examples 2 to 7 of the present invention is 56 to 87% by mass, which satisfies the reference of 50% by mass or more. In particular, in Examples 4 to 7 produced by the separation and recovery method involving the pulverization step S5, the carbon content is 82% by mass or more, which satisfies the higher standard of 70% by mass or more. On the other hand, the carbon content of the carbon-containing powder of Comparative Example 2 is as low as 34% by mass, which is less than 50% by mass as a reference. According to such a result, the unburned carbon particles are suitably separated from the FA by the separation and recovery method in the production method according to this embodiment, and a carbon-containing powder having a carbon content of at least 50% by mass or more is preferably obtained. Can be said.
[実施例8]
実施例8では、実施例2と同様の方法でFA(炭素含有率:11.8質量%)から得られた炭素含有粉(表5)を、焼結機の焼結工程で使用するコークスに混練し、焼結原料として使用した。そして、鍋試験により焼結工程での炭素含有粉の評価を行った。また、比較のため、通常操業であるコークスのみを用いた試験を以下、同様に実施した。 [Example 8]
In Example 8, the carbon-containing powder (Table 5) obtained from FA (carbon content: 11.8% by mass) in the same manner as in Example 2 was used for coke used in the sintering process of the sintering machine. Kneaded and used as a sintering raw material. And the carbon containing powder in a sintering process was evaluated by the pan test. For comparison, a test using only coke, which is a normal operation, was performed in the same manner.
実施例8では、実施例2と同様の方法でFA(炭素含有率:11.8質量%)から得られた炭素含有粉(表5)を、焼結機の焼結工程で使用するコークスに混練し、焼結原料として使用した。そして、鍋試験により焼結工程での炭素含有粉の評価を行った。また、比較のため、通常操業であるコークスのみを用いた試験を以下、同様に実施した。 [Example 8]
In Example 8, the carbon-containing powder (Table 5) obtained from FA (carbon content: 11.8% by mass) in the same manner as in Example 2 was used for coke used in the sintering process of the sintering machine. Kneaded and used as a sintering raw material. And the carbon containing powder in a sintering process was evaluated by the pan test. For comparison, a test using only coke, which is a normal operation, was performed in the same manner.
鍋試験では、耐火物を敷き詰めた鍋状炉に50kg程度の焼結原料を投入し、表面部に着火し、下方から空気吸引を行った。鍋試験の試料としては、スケール84質量%、石灰粉16質量%に対して、実施例2と同様にして得られた炭素含有粉(嵩比重:0.32g/cm3)が外数で8質量%となるように配合し、混合材料(乾粉)を作成した。さらに混合材料に水を外数で6質量%添加して混練した後、常温で乾燥し、直径2~5mmの疑似粒子からなる焼結試料50kgを作成した。
In the pot test, about 50 kg of sintered raw material was put into a pot-shaped furnace laid with refractories, the surface portion was ignited, and air was sucked from below. As a sample of the pan test, carbon-containing powder (bulk specific gravity: 0.32 g / cm 3 ) obtained in the same manner as in Example 2 with respect to 84% by mass of scale and 16% by mass of lime powder was an external number of 8 It mix | blended so that it might become mass%, and the mixed material (dry powder) was created. Furthermore, after adding 6% by mass of water to the mixed material and kneading, it was dried at room temperature to prepare 50 kg of a sintered sample made of pseudo particles having a diameter of 2 to 5 mm.
この焼結試料を、鍋試験装置に高さ600mmまで投入し、ブロアーにより1500mmAqで大気を吸引しつつ、点火炉にて表層に90秒点火し、焼成を行った。本焼結鉱作製試験結果は以下の表6の通りであった。表6に示す通り、炭素含有粉を混練した場合、通常操業であるコークス(N/C=0.021)のみと同等の歩留りで、塊状(≧5mm-篩目)の焼結鉱を得られた。したがって、上記炭素含有粉を焼結原料として使用することに問題がないことがわかった。一方で、焼結鉱製造時に発生する排ガス中のNOx平均濃度は低減した。これは炭素含有粉がコークスに比してN/C比で低窒素であるため、発生NOx量を低減できたと考えられる。
The sintered sample was put into a pan testing apparatus up to a height of 600 mm, and the surface layer was ignited for 90 seconds in an ignition furnace while firing at 1500 mmAq with a blower, followed by firing. The results of this sinter production test were as shown in Table 6 below. As shown in Table 6, when carbon-containing powder is kneaded, a massive (≧ 5 mm-sieving) sintered ore can be obtained with the same yield as that of coke (N / C = 0.021), which is a normal operation. It was. Therefore, it was found that there is no problem in using the carbon-containing powder as a sintering raw material. On the other hand, the average NOx concentration in the exhaust gas generated during the production of sintered ore was reduced. This is thought to be because the carbon-containing powder was low in nitrogen at an N / C ratio compared to coke, and thus the amount of generated NOx could be reduced.
[実施例9]
実施例9では、実施例2と同様の方法で得られた炭素含有粉(表6)と、他の粉体(スケール)を事前に混合して、嵩密度を増加させた。その上で、当該混合材料を焼結機の焼結工程で使用するコークスに混練し、焼結原料として使用した。そして、鍋試験により焼結工程での炭素含有粉の評価を行った。また、比較のため、通常操業であるコークスのみを用いた試験を以下、同様に実施した。 [Example 9]
In Example 9, the carbon-containing powder (Table 6) obtained by the same method as in Example 2 and another powder (scale) were mixed in advance to increase the bulk density. Then, the mixed material was kneaded into coke used in the sintering process of the sintering machine and used as a sintering raw material. And the carbon containing powder in a sintering process was evaluated by the pan test. For comparison, a test using only coke, which is a normal operation, was performed in the same manner.
実施例9では、実施例2と同様の方法で得られた炭素含有粉(表6)と、他の粉体(スケール)を事前に混合して、嵩密度を増加させた。その上で、当該混合材料を焼結機の焼結工程で使用するコークスに混練し、焼結原料として使用した。そして、鍋試験により焼結工程での炭素含有粉の評価を行った。また、比較のため、通常操業であるコークスのみを用いた試験を以下、同様に実施した。 [Example 9]
In Example 9, the carbon-containing powder (Table 6) obtained by the same method as in Example 2 and another powder (scale) were mixed in advance to increase the bulk density. Then, the mixed material was kneaded into coke used in the sintering process of the sintering machine and used as a sintering raw material. And the carbon containing powder in a sintering process was evaluated by the pan test. For comparison, a test using only coke, which is a normal operation, was performed in the same manner.
鍋試験では、耐火物を敷き詰めた鍋状炉に50kg程度の焼結原料を投入し、表面部に着火し、下方から空気吸引を行った。鍋試験の資料として、スケール84質量%、石灰粉16質量%、および、実施例2と同様にして得られた炭素含有物(嵩比重:0.32g/cm3)を外数で8質量%となるよう配合し、混合材料(乾粉)を作成した。混合する際に、炭素含有物とスケールの一部とを密閉容器内で事前に混合(配合率は重量比で4:6。混合後の嵩比重:1.2g/cm3)しておき、上記混合材料(乾粉)を作成した。さらに混合材料に水を外数で6質量%添加して混練した後、常温で乾燥し、直径2~5mmの疑似粒子からなる焼結試料50kgを作成した。
In the pot test, about 50 kg of sintered raw material was put into a pot-shaped furnace laid with refractories, the surface portion was ignited, and air was sucked from below. As a material for the pan test, 84% by mass of scale, 16% by mass of lime powder, and 8% by mass of the carbon content (bulk specific gravity: 0.32 g / cm 3 ) obtained in the same manner as in Example 2 were used. The mixture material (dry powder) was prepared. When mixing, the carbon-containing material and a part of the scale are mixed in advance in a sealed container (mixing ratio is 4: 6 by weight ratio, bulk specific gravity after mixing: 1.2 g / cm 3 ), The mixed material (dry powder) was prepared. Furthermore, after adding 6% by mass of water to the mixed material and kneading, it was dried at room temperature to prepare 50 kg of a sintered sample made of pseudo particles having a diameter of 2 to 5 mm.
この焼結試料を、鍋試験装置に高さ600mmまで投入し、ブロアーにより1500mmAqで大気を吸引しつつ、点火炉にて表層に90秒点火し、焼成を行った。本焼結鉱作成試験結果は以下の表7の通りであった。表7に示す通り、スケールと炭素含有粉を事前に混練した場合でも、通常操業であるコークスのみと同等の歩留りで、塊状(≧5mm-篩目)の焼結鉱を得られた。したがって、上記炭素含有粉を焼結原料として使用することに問題がないことがわかった。一方で、実施例8と同様に、焼結鉱製造時に発生する排ガス中のNOx平均濃度は低減した。これは炭素含有粉がコークスに比してN/C比で低窒素であるため、発生NOx量を低減できたと考えられる。さらに、混合材料(乾粉)を作成する際に、微細な炭素含有物に起因する粉塵はあまり発生せず、作業環境は改善された。
The sintered sample was put into a pan testing apparatus up to a height of 600 mm, and the surface layer was ignited for 90 seconds in an ignition furnace while firing at 1500 mmAq with a blower, followed by firing. The results of this sinter preparation test were as shown in Table 7 below. As shown in Table 7, even when the scale and carbon-containing powder were previously kneaded, massive (≧ 5 mm-sieving) sintered ore was obtained with a yield equivalent to that of coke, which is a normal operation. Therefore, it was found that there is no problem in using the carbon-containing powder as a sintering raw material. On the other hand, like Example 8, the NOx average concentration in the exhaust gas generated during the production of sintered ore was reduced. This is thought to be because the carbon-containing powder was low in nitrogen at an N / C ratio compared to coke, and thus the amount of generated NOx could be reduced. Furthermore, when producing a mixed material (dry powder), dust caused by fine carbon-containing materials was not generated so much and the working environment was improved.
[実施例10]
実施例10では、実施例2および実施例5で得られた炭素含有粉のサンプルについて、比表面積、SO2吸着能、脱硝能を測定した。その結果を表8に示す。 [Example 10]
In Example 10, the specific surface area, SO 2 adsorption capacity, and denitration capacity of the carbon-containing powder samples obtained in Example 2 and Example 5 were measured. The results are shown in Table 8.
実施例10では、実施例2および実施例5で得られた炭素含有粉のサンプルについて、比表面積、SO2吸着能、脱硝能を測定した。その結果を表8に示す。 [Example 10]
In Example 10, the specific surface area, SO 2 adsorption capacity, and denitration capacity of the carbon-containing powder samples obtained in Example 2 and Example 5 were measured. The results are shown in Table 8.
両サンプルとも、SO2吸着能、脱硝能を確認することができた。実施例2で得られた炭素含有粉をSEMで観察すると、多数の微細孔(直径2μm未満)が観測された。この多数の微細孔により、炭素含有粉の比表面積が増加し、SO2吸着能、脱硝能が備わったと考えられる。また、この微細孔には、略球状の酸化物粒子が入り込み、微細孔の深部を塞いでいることが多いことが観察された。これにより、SO2吸着能もしくは脱硝能として作用できない微細孔部分があると考える。これに対し、実施例5の炭素含有粉は、比表面積は粉砕により約2倍に増加しているが、SO2吸着能、脱硝能はそれ以上に増加している。これは、粉砕により、微細孔内に入り込んだ略球状の酸化物が取り除かれ、微細孔のほとんどがSO2吸着能、脱硝能として作用したためと考えられる。
In both samples, SO 2 adsorption ability and denitration ability could be confirmed. When the carbon-containing powder obtained in Example 2 was observed with an SEM, a large number of micropores (diameter less than 2 μm) were observed. The large number of micropores increases the specific surface area of the carbon-containing powder, and is considered to have SO 2 adsorption capacity and denitration capacity. Further, it was observed that substantially spherical oxide particles entered the micropores and often closed the deep portions of the micropores. Accordingly, it is considered that there are micropore portions that cannot function as SO 2 adsorption ability or denitration ability. On the other hand, the specific surface area of the carbon-containing powder of Example 5 was increased by a factor of about 2 due to pulverization, but the SO 2 adsorption capacity and denitration capacity were further increased. This is presumably because the substantially spherical oxide that had entered the fine pores was removed by pulverization, and most of the fine pores acted as SO 2 adsorption ability and denitration ability.
[実施例11]
実施例11では、図11に示す向流型多段連続プロセスにより、FAから炭素含有粉を回収した。実施例11の試験では、図6に示す分離回収装置5を用いて、1段目の水洗浄工程(S22_1)を行う向流型4段連続プロセス(図11でM=1,N=4のとき)を実施した。ミキサー51A、51Bの容量はそれぞれ0.3Lであった。セトラー52A、52Bとして上昇流式分離装置(直径:40mm、高さ:300mm)を用いた。水洗浄工程(S22_1)のミキサー51Bに、水を1L/分投入し、4段目の粗分離工程(S21_4)のミキサー51Aに、臭素系有機溶剤(1-ブロモプロパン)を1L/分投入し、1段目の粗分離工程(S21_1)のミキサー51Aに、FAを75g/分投入した。 [Example 11]
In Example 11, carbon-containing powder was recovered from FA by the countercurrent multistage continuous process shown in FIG. In the test of Example 11, a countercurrent type four-stage continuous process (M = 1 and N = 4 in FIG. 11) in which the first stage water washing step (S22_1) is performed using the separation andrecovery device 5 shown in FIG. When). The capacities of the mixers 51A and 51B were each 0.3L. An upflow separator (diameter: 40 mm, height: 300 mm) was used as the settlers 52A and 52B. 1 L / min of water is added to the mixer 51B of the water washing step (S22_1), and 1 L / min of bromine-based organic solvent (1-bromopropane) is added to the mixer 51A of the coarse separation step (S21_4) of the fourth stage. 75 g / min of FA was added to the mixer 51A in the first-stage rough separation step (S21_1).
実施例11では、図11に示す向流型多段連続プロセスにより、FAから炭素含有粉を回収した。実施例11の試験では、図6に示す分離回収装置5を用いて、1段目の水洗浄工程(S22_1)を行う向流型4段連続プロセス(図11でM=1,N=4のとき)を実施した。ミキサー51A、51Bの容量はそれぞれ0.3Lであった。セトラー52A、52Bとして上昇流式分離装置(直径:40mm、高さ:300mm)を用いた。水洗浄工程(S22_1)のミキサー51Bに、水を1L/分投入し、4段目の粗分離工程(S21_4)のミキサー51Aに、臭素系有機溶剤(1-ブロモプロパン)を1L/分投入し、1段目の粗分離工程(S21_1)のミキサー51Aに、FAを75g/分投入した。 [Example 11]
In Example 11, carbon-containing powder was recovered from FA by the countercurrent multistage continuous process shown in FIG. In the test of Example 11, a countercurrent type four-stage continuous process (M = 1 and N = 4 in FIG. 11) in which the first stage water washing step (S22_1) is performed using the separation and
セトラー52A及びセトラー52Bの下部には、臭素系有機溶剤相が形成され、上部には水相が形成され、水相と空気の間には臭素系有機溶剤相の薄膜が形成された。水相の表層部から下に約3cmの箇所から水相を連続して1L/分で引き抜き、水相の分析用サンプルを得た。一方、臭素系有機溶剤相の最下部から上に約3cmの箇所から臭素系有機溶剤相を連続して1L/分で引き抜き、溶剤相の分析用サンプルを得た。各サンプルを遠心分離(1,700G×30秒間)にて脱液した後、乾燥炉にて乾燥し、固形物を回収した。上記式(4)と式(5)に基づいて、未燃カーボン粒子分離率KA、親水性粒子回収率KBを計算した。なお、使用したFA中には、カーボンが13質量%含まれ、その粒子径は200μm以下であった。
A bromine-based organic solvent phase was formed at the lower part of the settler 52A and the settler 52B, an aqueous phase was formed at the upper part, and a thin film of a bromine-based organic solvent phase was formed between the aqueous phase and air. The aqueous phase was continuously withdrawn at a rate of about 1 L / min from the surface layer portion of the aqueous phase, and a sample for analysis of the aqueous phase was obtained. On the other hand, the bromine-based organic solvent phase was continuously withdrawn from the bottom of the bromine-based organic solvent phase at a rate of about 3 cm at a rate of 1 L / min to obtain a solvent phase analysis sample. Each sample was drained by centrifugation (1,700 G × 30 seconds) and then dried in a drying furnace to recover a solid. Based on the equation (5) above equation (4), the unburned carbon particles separation rate K A, was calculated hydrophilic particles recovery K B. The FA used contained 13% by mass of carbon and had a particle size of 200 μm or less.
この実施例11の試験の結果、未燃カーボン粒子分離率KAは82質量%であり、親水性粒子回収率KBは91質量%であった。また、図13に示すように、4段目の粗分離工程(S21_4)の後、第1回収工程(S3)で水相から回収した固形物中の未燃カーボン粒子の含有率CBは、2.8質量%であった。水洗浄工程(S22_1)の後、第2回収工程(S4)で臭素系有機溶剤相から回収した固形物中の未燃カーボン粒子の含有率CAは、58質量%であった。かかる試験結果によれば、実施例11の向流型4段連続プロセスでは、水相から回収した固形物中の未燃カーボン粒子の含有率CBを低位にしながら、臭素系有機溶剤相から回収した固形物中の未燃カーボン粒子の含有率CAを改善できることが確認された。
The results of the tests of this example 11, the unburned carbon particles separation rate K A is 82 mass%, hydrophilic particles recovery K B was 91% by mass. Further, as shown in FIG. 13, after the fourth coarse separation step (S21_4), the content C B of unburned carbon particles in the solid recovered from the aqueous phase in the first recovery step (S3) is: It was 2.8% by mass. After the water washing step (S22_1), the content C A of unburned carbon particles solids in the recovered bromine-based organic solvent phase in the second recovery step (S4) was 58 wt%. According to the test results, in the countercurrent four-stage continuous process of Example 11, recovery from the bromine-based organic solvent phase was performed while the unburned carbon particle content C B in the solid recovered from the aqueous phase was low. it was confirmed that the improved content C a of the unburned carbon particles solids in.
以上、添付図面を参照しながら本発明の好適な実施形態について詳細に説明したが、本発明はかかる例に限定されない。本発明の属する技術の分野における通常の知識を有する者であれば、特許請求の範囲に記載された技術的思想の範疇内において、各種の変更例または修正例に想到し得ることは明らかであり、これらについても、当然に本発明の技術的範囲に属するものと了解される。
The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious that a person having ordinary knowledge in the technical field to which the present invention pertains can come up with various changes or modifications within the scope of the technical idea described in the claims. Of course, it is understood that these also belong to the technical scope of the present invention.
FA フライアッシュ
P0 炭素含有粉
P1 酸化物粒子
P2 未燃カーボン粒子(炭素粒子)
ph1 水相
ph2 疎水性溶剤相(疎水性液体相)
4 ボイラー
5 分離回収装置
51A、51B ミキサー(混合装置)
52A、52B セトラー(分離装置)
61 第1回収装置
611 遠心分離機
612 乾燥装置
613 コンデンサー
62 第2回収装置
621 遠心分離機
622 乾燥装置
623 コンデンサー
FA fly ash P0 carbon-containing powder P1 oxide particles P2 unburned carbon particles (carbon particles)
ph1 aqueous phase ph2 hydrophobic solvent phase (hydrophobic liquid phase)
4Boiler 5 Separation and recovery device 51A, 51B Mixer (mixing device)
52A, 52B Settler (separator)
61First recovery device 611 Centrifuge 612 Drying device 613 Condenser 62 Second recovery device 621 Centrifuge 622 Drying device 623 Condenser
P0 炭素含有粉
P1 酸化物粒子
P2 未燃カーボン粒子(炭素粒子)
ph1 水相
ph2 疎水性溶剤相(疎水性液体相)
4 ボイラー
5 分離回収装置
51A、51B ミキサー(混合装置)
52A、52B セトラー(分離装置)
61 第1回収装置
611 遠心分離機
612 乾燥装置
613 コンデンサー
62 第2回収装置
621 遠心分離機
622 乾燥装置
623 コンデンサー
FA fly ash P0 carbon-containing powder P1 oxide particles P2 unburned carbon particles (carbon particles)
ph1 aqueous phase ph2 hydrophobic solvent phase (hydrophobic liquid phase)
4
52A, 52B Settler (separator)
61
Claims (18)
- 炭素粒子と酸化物粒子を含有する炭素含有粉であって、
前記炭素含有粉中の炭素成分の含有率が、50質量%以上、95質量%以下であり、
前記酸化物粒子は、SiO2成分又はAl2O3成分のうちいずれか一方若しくは双方を含む化合物からなる粒子であり、前記酸化物粒子中の前記SiO2成分と前記Al2O3成分の合計の含有率が、75質量%以上であり、
前記炭素粒子は、複数の細孔が形成された多孔質粒子であり、
前記酸化物粒子の少なくとも一部は、前記炭素粒子の細孔中に存在する、炭素含有粉。 A carbon-containing powder containing carbon particles and oxide particles,
The carbon component content in the carbon-containing powder is 50% by mass or more and 95% by mass or less,
The oxide particles are particles composed of a compound containing one or both one of the SiO 2 component or Al 2 O 3 component, the total of the said SiO 2 component Al 2 O 3 component of the oxide particles The content of is 75% by mass or more,
The carbon particles are porous particles in which a plurality of pores are formed,
At least a part of the oxide particles is a carbon-containing powder that exists in the pores of the carbon particles. - 前記炭素含有粉中の前記炭素成分の含有率が、70質量%以上、95質量%以下である、請求項1に記載の炭素含有粉。 The carbon-containing powder according to claim 1, wherein the content of the carbon component in the carbon-containing powder is 70% by mass or more and 95% by mass or less.
- 前記炭素含有粉に含まれる窒素成分と前記炭素成分の質量比であるN/C比が、0超、0.02以下である、請求項1又は2に記載の炭素含有粉。 The carbon-containing powder according to claim 1 or 2, wherein an N / C ratio, which is a mass ratio of the nitrogen component and the carbon component contained in the carbon-containing powder, is more than 0 and 0.02 or less.
- 前記酸化物粒子の粒子径が、体積基準の50%粒子径で、1~20μmである、請求項1~3のいずれか1項に記載の炭素含有粉。 The carbon-containing powder according to any one of claims 1 to 3, wherein a particle diameter of the oxide particles is 50% on a volume basis and is 1 to 20 µm.
- 前記酸化物粒子の円形度の平均値が、0.9超、1以下である、請求項1~4のいずれか1項に記載の炭素含有粉。 The carbon-containing powder according to any one of claims 1 to 4, wherein an average value of circularity of the oxide particles is more than 0.9 and 1 or less.
- 前記酸化物粒子中の前記SiO2成分の含有率が、50質量%以上、80質量%以下であり、
前記酸化物粒子中の前記Al2O3成分の含有率が、10質量%以上、30質量%以下である、請求項1~5のいずれか1項に記載の炭素含有粉。 The content of the SiO 2 component in the oxide particles is 50% by mass or more and 80% by mass or less,
The carbon-containing powder according to any one of claims 1 to 5, wherein a content of the Al 2 O 3 component in the oxide particles is 10% by mass or more and 30% by mass or less. - 前記炭素含有粉の比表面積が、50~300m2/gである、請求項1~6のいずれか1項に記載の炭素含有粉。 The carbon-containing powder according to any one of claims 1 to 6, wherein the carbon-containing powder has a specific surface area of 50 to 300 m 2 / g.
- フライアッシュに由来し、炭素粒子と酸化物粒子とが混在する混合物から、炭素粒子と酸化物粒子とを分離する分離方法であって、
前記混合物と、水と、前記水より比重が大きい疎水性液体とを混合して混合液を生成する混合工程と、
前記混合液を静置し、前記炭素粒子を含む疎水性液体相と、前記酸化物粒子を含む水相とに分離させることにより、前記炭素粒子と前記酸化物粒子とを分離する比重分離工程と、
を含む、分離方法。 A separation method for separating carbon particles and oxide particles from a mixture of carbon particles and oxide particles derived from fly ash,
A mixing step of mixing the mixture, water, and a hydrophobic liquid having a specific gravity greater than that of the water to produce a mixture;
A specific gravity separation step of separating the carbon particles and the oxide particles by allowing the mixed liquid to stand and separating the mixture into a hydrophobic liquid phase containing the carbon particles and an aqueous phase containing the oxide particles; ,
Including a separation method. - 前記比重分離工程で分離された前記水相から、前記水を分離することにより、前記酸化物粒子を回収する第1回収工程を更に含む、請求項8に記載の分離方法。 The separation method according to claim 8, further comprising a first recovery step of recovering the oxide particles by separating the water from the aqueous phase separated in the specific gravity separation step.
- 前記比重分離工程で分離された前記疎水性液体相から、前記疎水性液体を分離することにより、炭素含有粉を回収する第2回収工程を更に含み、
前記炭素含有粉は、前記炭素粒子と前記酸化物粒子を含有し、
前記炭素含有粉中の炭素成分の含有率が、50質量%以上、95質量%以下であり、
前記酸化物粒子は、SiO2成分又はAl2O3成分のうちいずれか一方若しくは双方を含む化合物からなる粒子であり、前記酸化物粒子中の前記SiO2成分と前記Al2O3成分の合計の含有率が、75質量%以上であり、
前記炭素粒子は、複数の細孔が形成された多孔質粒子であり、
前記酸化物粒子の少なくとも一部は、前記炭素粒子の細孔中に存在する、請求項8又は9に記載の分離方法。 A second recovery step of recovering the carbon-containing powder by separating the hydrophobic liquid from the hydrophobic liquid phase separated in the specific gravity separation step;
The carbon-containing powder contains the carbon particles and the oxide particles,
The carbon component content in the carbon-containing powder is 50% by mass or more and 95% by mass or less,
The oxide particles are particles composed of a compound containing one or both one of the SiO 2 component or Al 2 O 3 component, the total of the said SiO 2 component Al 2 O 3 component of the oxide particles The content of is 75% by mass or more,
The carbon particles are porous particles in which a plurality of pores are formed,
The separation method according to claim 8 or 9, wherein at least a part of the oxide particles are present in pores of the carbon particles. - 前記炭素含有粉に含まれる窒素成分と前記炭素成分の質量比であるN/C比が、0.02以下である、請求項10に記載の分離方法。 The separation method according to claim 10, wherein the N / C ratio, which is a mass ratio of the nitrogen component and the carbon component contained in the carbon-containing powder, is 0.02 or less.
- 向流型多段連続プロセスにより、前記混合工程と前記比重分離工程の組合せを多段階繰り返す、請求項8~11のいずれか1項に記載の分離方法。 The separation method according to any one of claims 8 to 11, wherein the combination of the mixing step and the specific gravity separation step is repeated in multiple stages by a countercurrent multi-stage continuous process.
- 前記比重分離工程の前、又は前記比重分離工程中に、疎水性液体又は水のうちいずれか一方若しくは双方と、前記混合物との混合液に対して粉砕処理を行うことにより、当該混合液に含まれる前記炭素粒子を粉砕する粉砕工程を更に含む、請求項8~12のいずれか1項に記載の、分離方法。 Included in the liquid mixture by subjecting the liquid mixture of the mixture with either one or both of a hydrophobic liquid or water and the mixture before or during the specific gravity separation process. The separation method according to any one of claims 8 to 12, further comprising a pulverizing step of pulverizing the carbon particles.
- 前記粉砕工程において、ビーズを用いた粉砕処理により、前記混合液に含まれる前記炭素粒子を粉砕する、請求項13記載の分離方法。 The separation method according to claim 13, wherein in the pulverization step, the carbon particles contained in the mixed liquid are pulverized by a pulverization process using beads.
- 前記フライアッシュは、石炭を燃焼させることにより生成され、
前記炭素粒子は、前記燃焼時に燃え残った未燃カーボンの粒子であり、
前記酸化物粒子は、前記石炭の灰分が前記燃焼時に溶融して粒状となった粒子である、請求項8~14のいずれか1項に記載の分離方法。 The fly ash is produced by burning coal,
The carbon particles are unburned carbon particles left unburned during the combustion,
The separation method according to any one of claims 8 to 14, wherein the oxide particles are particles in which the coal ash is melted and granulated during the combustion. - 前記比重分離工程は、
前記混合液を静置することにより、前記炭素粒子を含む疎水性液体相と、前記酸化物粒子を含む水相とに分離する粗分離工程と、
前記粗分離工程で分離された前記疎水性液体相に水を加えて混合し、当該疎水性液体相と水との混合液を静置することにより、前記炭素粒子を含む疎水性液体相と、前記酸化物粒子を含む水相とに分離する水洗浄工程と、
を含む、請求項8~15のいずれか1項に記載の分離方法。 The specific gravity separation step includes:
A rough separation step of separating the liquid mixture into a hydrophobic liquid phase containing the carbon particles and an aqueous phase containing the oxide particles by allowing the mixture to stand.
Water is added to and mixed with the hydrophobic liquid phase separated in the rough separation step, and the liquid mixture of the hydrophobic liquid phase and water is allowed to stand, whereby the hydrophobic liquid phase containing the carbon particles, A water washing step for separating into an aqueous phase containing the oxide particles;
The separation method according to any one of claims 8 to 15, comprising: - 請求項1~7のいずれか1項に記載の炭素含有粉を、焼結機、燃焼炉若しくは転炉で使用される石炭の代替として、又はSO2吸着材若しくは脱硝材として利用する、炭素含有粉の利用方法。 The carbon-containing powder according to any one of claims 1 to 7, which is used as a substitute for coal used in a sintering machine, a combustion furnace or a converter, or as an SO 2 adsorbent or denitration material. How to use the powder.
- 前記炭素含有粉と他の粉体とを混合し、前記炭素含有粉の嵩比重を大きくした後に、当該炭素含有粉を利用する、請求項17に記載の炭素含有粉の利用方法。 The method for using carbon-containing powder according to claim 17, wherein the carbon-containing powder is used after mixing the carbon-containing powder with another powder and increasing the bulk specific gravity of the carbon-containing powder.
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