JP2005042202A - Method and device for treating waste activated carbon - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for treating waste activated carbon by which the waste activated carbon can effectively be utilized as the resource with considering composition and characteristics of the waste activated carbon, absorbed materials, etc. <P>SOLUTION: In the treating method of the waste activated carbon, the waste activated carbon is added to sintering raw material and the sintering raw material is granulated by using a mixer while adding water, if necessary, lime, and pseudo-grains are formed and this raw material is supplied into a sintering machine and the waste activated carbon surrounded by the pseudo-grain is made to function as the heat-source and the reducing agent of mineral and thus, the carbon contributes to the sintering reaction by promoting the generation of fused liquid to the low melting point mineral. The waste activated carbon is generated as the formation, in which various kinds of materials are absorbed into the activated carbon. By paying attention to that the waste activated carbon at ≥80% in the market has no problem as the absorbed material on the production of the iron and steel and also, this waste activated carbon can effectively be utilized as the resource, this waste activated carbon is effectively utilized as the sintering raw material in the iron works. SiO<SB>2</SB>, CaO and Al<SB>2</SB>O<SB>3</SB>in the waste activated carbon mixed in the sintering raw material, are effectively utilized as the blast furnace slag. Further, C in the waste activated carbon and (C, H) in the absorptive material, are formed as the fuel and the reducing agent and effectively utilized as a substitution for powdery coke. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a waste activated carbon treatment method and apparatus for treating used activated carbon (waste activated carbon) applied to water treatment of upper / sewage water, air purification, and the like.

  Activated carbon is widely used not only for water treatment of water, sewage and industrial water, air purification such as air pollution and bad odor, but also for manufacturing processes of food manufacturers. Such activated carbon is usually produced by activation treatment using coconut shells, coal, or the like as raw materials, and the shapes thereof are various such as granular, powdery, and fibrous. Since activated carbon adsorbs various substances on the surface or in the pores, the adsorption performance gradually deteriorates with use. For this reason, cheap activated carbon is made into one-time disposable, without being recycled. In addition, there is activated carbon that is reused by removing adhered substances by regeneration treatment or dry distillation treatment. However, the performance decreases due to repeated recycling, and the target adsorption performance cannot be achieved. Conventionally, such used activated carbon has been incinerated or landfilled.

  However, when the activated carbon is incinerated or landfilled, it cannot be effectively used as an energy resource. In addition, since the waste activated carbon contains ash, if it is simply incinerated, sensible heat is lost to the ash and slag is generated. This slag treatment is also a problem.

  Accordingly, an object of the present invention is to provide a waste activated carbon treatment method and treatment apparatus that can effectively use waste activated carbon as a resource in consideration of the components and properties of the waste activated carbon, adsorbed substances, and the like.

  The inventor investigated the components and properties of the waste activated carbon and the adsorbed substances. An analysis example of the results is shown in Table 1.

  Waste activated carbon is generated in the form of various adsorbed substances adsorbed on the activated carbon. Over 80% of the waste activated carbon on the market, the inventor pays attention to the fact that the adsorbed material has no problem in steel production, and conversely, the activated carbon can be effectively used as a resource. Invented a method of treating waste activated carbon. Specifically, the present invention adds waste activated carbon to the sintering raw material, and using a mixing device, granulate the sintering raw material by adding water and quick lime as necessary, to form pseudo particles, The waste is characterized in that the raw material is supplied to the sintering machine, the coarse grain part functions as a heat source, and the fine powder part functions as a reducing agent for ore, thereby promoting the melt generation of low melting point minerals and making them useful for the sintering reaction. The above-mentioned problem was solved by the activated carbon treatment method.

According to this invention, SiO ₂ , CaO, Al ₂ O ₃ in the waste activated carbon mixed with the sintering raw material contributes as a slag binder at the time of manufacturing the sintered ore, whereby the sintering raw material is agglomerated as the sintered ore. It becomes. Therefore, SiO ₂ , CaO, Al ₂ O ₃ in the waste activated carbon is finally effectively used as blast furnace slag. Further, C in the waste activated carbon and (C, H) in the adsorbed material become a fuel and a reducing agent, and are effectively used as a substitute for the powder coke.

  Further, the present invention comprises a waste activated carbon mixing means for mixing waste activated carbon with a sintered raw material, and a sintering machine for sintering the sintered raw material mixed with this waste activated carbon, and the waste activated carbon mixing means comprises waste activated carbon. In addition, the waste activated carbon is added to the sintered raw material in front of the mixing device for granulating the sintered raw material, and the waste activated carbon and the sintered raw material are granulated in the mixing device, and the waste activated carbon is mixed and granulated with the sintered raw material. The above-described problems have been solved by a waste activated carbon treatment apparatus characterized by the following. Here, a pug mill, a drum mixer, or the like is used as the mixing device.

  When the waste activated carbon is granulated together with the sintering raw material, pseudo particles are formed. Thereby, it can prevent that the air permeability of the raw material layer of a sintering machine deteriorates, and a sintering reaction can be advanced uniformly and fully. Moreover, waste activated carbon can be mixed with a sintering raw material by utilizing the existing mixing apparatus, without providing new equipment.

According to the present invention, the waste activated carbon is mixed with the sintered raw material, and the sintered raw material mixed with the waste activated carbon is sintered, so that SiO ₂ , CaO, Al ₂ O ₃ in the waste activated carbon mixed with the sintered raw material is sintered. However, it contributes as a slag binder at the time of manufacturing a sintered ore, and thereby the sintered raw material is agglomerated as a sintered ore. Therefore, SiO ₂ , CaO, Al ₂ O ₃ in the waste activated carbon is finally effectively used as blast furnace slag. Further, C in the waste activated carbon and (C, H) in the adsorbed material become a fuel and a reducing agent, and are effectively used as a substitute for the powder coke.

  Hereinafter, a waste activated carbon treatment apparatus according to an embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 shows a schematic configuration diagram of a waste activated carbon treatment apparatus. This waste activated carbon treatment apparatus sinters the waste activated carbon mixing device 1 as waste activated carbon mixing means for mixing waste activated carbon with raw materials for manufacturing sintered ore (hereinafter referred to as sintered raw materials) and the sintered raw material mixed with waste activated carbon. The sintering machine 2 to be provided.

  The waste activated carbon mixing device 1 conveys a plurality of raw material tanks 3 that store the sintered raw materials for each type, a raw material cutting device 4 that cuts out a predetermined amount of the sintered raw materials in the raw material tank 3, and the cut sintered raw materials. A sintered raw material transport conveyor 5 and drum mixers 7a and 7b as mixing devices for granulating the waste activated carbon and the sintered raw material are provided. The drum mixers 7a and 7b are composed of a first drum mixer 7a and a second drum mixer 7b arranged in series. This waste activated carbon mixing apparatus 1 adds waste activated carbon to the sintering raw material in front of the drum mixers 7a and 7b for granulating the waste activated carbon and the sintering raw material, and the waste activated carbon and the sintering raw material are produced by the drum mixers 7a and 7b. It is granulated and the waste activated carbon adheres to the sintering raw material.

  The waste activated carbon discharged from the discharger is packed in a flexible container and stored in the storage of the sintering plant by a truck or the like. A predetermined amount of the flexible container 15 is lifted by lifting means such as a hoist 16, and the waste activated carbon in the flexible container is transferred to the activated carbon charging hopper 17. The waste activated carbon in the activated carbon charging hopper 17 is cut out by a cutting device and added to the sintered raw material via the chain conveyor 19. The waste activated carbon having a large particle size is added to the powder coke, pulverized by the rod mill 18, and supplied to the raw material tank 3.

  The waste activated carbon is supplied to a first drum mixer 7a that rotates together with a mixed sintered raw material (hereinafter referred to as a mixed raw material). The first drum mixer 7a mixes and granulates the waste activated carbon and the mixed raw material. The first drum mixer 7a is provided with a hot water or cold water addition device for granulating the raw material, and controls the water content in the mixed raw material to a constant value. The hot water or cold water addition apparatus adds water so that the raw material moisture is about 7 to 8%. When the raw material moves while rolling in the first drum mixer 7a, the fine powder adheres to the coarse particles due to the surface tension of the added water to form pseudo particles. The raw material granulated to some extent by the first drum mixer 7a is supplied to the second drum mixer 7b, and further granulation is continued. The second drum mixer 7b is used for the purpose of further promoting granulation.

  In general, when the mixed raw material is fired with a sintering machine, if there is a large amount of fine powder, the air permeability of the raw material on the sintering machine is deteriorated and the firing speed is lowered, so that the productivity is lowered. As a countermeasure, two large rotating drum mixers are usually installed between the raw material hopper and the sintering machine to reduce the fine powder and increase the average particle size by making the raw material components uniform and granulating. . As sintering raw materials, for example, about 55% iron ore powder, about 15% in-house recovered dust, about 14% return ore (sintered ore whose particle size is too small to be a product), and about 14% limestone, quicklime, gabbro, dolomite, etc.) and about 3% coke powder (fuel). The particle size of the sintered raw material varies depending on the type of raw material, but the particle size configuration of the mixed material (hereinafter referred to as mixed raw material) is as shown in Table 2, for example.

  From this table, it can be seen that before granulation, fine particles having a particle size of 0.25 mm to 0.125 mm account for 10%, and finer particles of 0.125 mm (125 μm) or less account for 6% before mixing. . On the other hand, the particle size composition of the mixed raw material after completion of granulation is such that fine particles of 0.25 mm to 0.125 mm are reduced to 5%, and there is no fine powder of 125 μm or less. Moreover, the average particle diameter of the mixed raw material increases from 2.1 mm to 2.5 mm before and after granulation. In addition, in order to improve productivity, a part of limestone of the sintering raw material may be replaced with quick lime having high activity to increase granulation property.

  As shown in FIG. 1, the granulated mixed raw material and waste activated carbon are charged onto a pallet of a sintering machine body 12 through a raw material supply device 11. The ignition furnace 13 ignites uniformly the coke on the surface of the mixed raw material. The main body 12 of the sintering machine automatically sends the pallet to the discharge side. A wind box is provided at the lower part of the pallet, and since the wind is sucked downward by the exhaust device, most of the powder coke mixed in the sintered raw material is expressed by the following reaction formula (1). It burns and supplies the heat necessary for the melting reaction of the raw ore particles.

  Further, a small part of the coke powder is taken into the pseudo particles, and a part of the powder ore is reduced by the following reaction formula (2) and / or (3), and a low melting point melt is generated by the following reaction formula (4). . The sintering reaction is promoted through this melt, and the whole is agglomerated.

Role of powder coke (C) in sinter production process 1) Heat source: Function as fuel (large particle size)
C + O ₂ → CO ₂ + Q (heat generation) (1)
2) Low melting point melt production:
(A) Low basicity side: works as a reducing agent by the heat of 1) above (small particle size)
Fe ₂ O ₃ +2 H → 2FeO + H ₂ O (2)
Fe ₂ O ₃ + C → 2FeO + CO (3)
2FeO + SiO ₂ → 2FeO · SiO ₂ firelight (MP = 1170 ° C.) (4)
(B) High basicity side: CaO + 2Fe ₂ O ₃ → CaO · 2Fe ₂ O ₃ calcium ferrite (MP = 1230 ° C.) by the heat of 1) (5)
The low melting point melt of 2) is generated by the heat of 1), and the raw material particles are combined in the cooling process to form a sintered ore (sintering reaction does not occur only by simple heating).

Among the waste activated carbon, crushed coal has a size of 0.2 to 5 mm, powdered coal has a size of 0.001 to 2 mm, and formed coal has a size of 1 to 10 mm. Among the activated carbons, those with a small particle size are used as they are, and those with a large particle size are sized using a rod mill or the like as described above, and then put into a sintering machine. Of C in the waste activated carbon and (C, H) in the adsorbed material, those having a large particle size are combusted according to the reaction formula (1), and supply heat necessary for the melting reaction of the raw ore particles. In the case of fine particles, a part of the fine ore is reduced by the reaction formula (2) and / or (3). Therefore, C in the waste activated carbon and (C, H) in the adsorbent can be effectively used as a substitute for the powder coke. In addition, SiO ₂ , CaO, Al ₂ O ₃ in the waste activated carbon in the waste activated carbon contributes as a slag binder during the production of the sintered ore, whereby the sintered raw material is agglomerated as the sintered ore. Therefore, SiO ₂ , CaO, and Al ₂ O ₃ in the waste activated carbon are finally effectively used as blast furnace slag.

  FIG. 2 shows a waste toner supply device 6 that supplies waste toner to the waste activated carbon treatment device. The waste toner supply device 6 adds waste toner to the sintering raw material in addition to the waste activated carbon.

  The inventors investigated the components and properties of the toner. As a result, it has been found that there are two types of toner, toner B mainly composed of resin and toner A in which iron powder is added to the resin. Table 3 shows the components, physical properties, and production ratios of toner A and toner B.

  As shown in this table, the component of toner A occupying 70 to 80% of the market is composed of iron powder of 40 to 50% weight for imparting magnetism and resin of 50 to 60% weight. More specifically, the component of toner A is composed of 35% styrene acrylic resin, 17% polyester resin, 3% polyolefin, 44% iron powder (magnetite), and 1% dye (blue), and is mainly composed of one component. Used as a black toner in the method. The component of toner B is composed of 90% by weight resin and pigment, and is mainly used as a color toner in the two-component development method. Further, comparing the physical properties of the toner A and the toner B, the specific gravity is slightly larger because the toner A contains iron than the toner B, the melting points are almost equal in both the toner A and the toner B, and the water solubility is both in the toner A and the toner B I found almost no. The properties of toner A and toner B are both ultrafine particles having a particle diameter of several to several tens of micrometers. The toner A includes toner containing 85 to 90% by weight of iron powder.

  The present inventor noticed that both the toners A and B are ultrafine particles having a particle diameter of several to several tens of μm, and mixed the waste toner with the sintering material, and the sintering material mixed with the waste toner. When sintering, waste toner was effectively used as a reducing agent for ore.

The iron powder in the waste toner mixed with the sintering raw material is effectively used as an iron source. In addition, since the waste toner is an ultrafine particle having a particle size of several to several tens of μm, when the sintering raw material is granulated with a mixing device, most of the waste toner is taken into the pseudo particles, and the waste toner resin The components (C, H) can function as a reducing agent for iron ore. Reduction of the iron ore produces a low-melting-point mineral called firelite (2FeO.SiO ₂ ), and the melt acts as a raw material binder upon cooling, and as a result, the raw material is agglomerated as sintered ore. Therefore, the waste toner is effectively used for the sintering reaction as chemical recycling.

  A waste toner supply device 6 that supplies waste toner onto the sintering material transport conveyor 5 includes a hopper 8 that stores waste toner carried in a flexible container or a lorry vehicle, and a quantitative cutout that cuts out a certain amount of waste toner in the hopper 8. A rotary feeder 9 as an apparatus and a chain conveyor 10 as a waste toner transport device for transporting the cut out waste toner onto the sintered raw material transport conveyor 5 are configured. Here, since waste toner may cause dust explosion, the hopper 8 is provided with countermeasures against static electricity.

  The waste toner is supplied to a first drum mixer 7a that rotates together with a mixed sintered raw material (hereinafter referred to as a mixed raw material). The first drum mixer 7a mixes and granulates the waste toner and the mixed raw material. As described above, the first drum mixer 7a is provided with a hot water or cold water addition device for granulating the raw material, and controls the water content in the mixed raw material to a constant value.

  The waste toner is added to the sintering raw material before the first drum mixer 7a. Then, the first and second drum mixers 7a and 7b granulate the waste toner and the sintering raw material, and adhere the waste toner to the sintering raw material. When the waste toner adheres to the coarse raw material, pseudo particles are formed. Thereby, it can prevent that the air permeability of the raw material layer of the sintering machine 2 is deteriorated, and the sintering reaction can proceed uniformly and sufficiently. Further, by using the existing first and second drum mixers 7a and 7b, waste toner can be mixed with the sintering raw material without providing new equipment.

  As shown in FIG. 1, the granulated mixed raw material and waste toner are charged onto a pallet of a sintering machine main body 12 through a raw material supply device 11. The ignition furnace 13 ignites uniformly the coke on the surface of the mixed raw material. The main body 12 of the sintering machine automatically sends the pallet to the discharge side. A wind box is provided at the lower part of the pallet, and since the wind is sucked down by the air exhaust device, most of the powder coke mixed in the sintered raw material is expressed by the above reaction formula (1). It burns and supplies the heat necessary for the melting reaction of the raw ore particles.

  As described above, a small part of the coke powder is taken into the pseudo particles, a part of the powder ore is reduced by the above reaction formula (2) and / or (3), and the low melting point is melted by the above reaction formula (4). A liquid is produced. The sintering reaction is promoted through this melt, and the whole is agglomerated. At this time, since the waste toner is sufficiently small compared to the coke powder (waste toner diameter = 0.001 to 0.010 mmφ, powder coke diameter = average 2 mmφ, see Table 4 below), almost the entire amount is taken into the pseudo particles and used as a reducing agent. Found to be an alternative to ground coke. Further, the iron content of the waste toner can be effectively used as an iron source.

  Examples of the invention are shown below. Add the waste activated carbon to the sintering raw material, add the required amount of warm water of 80 ° C to the 1st drum mixer (diameter 4.2m, length 14m, rotation speed 6rpm) so that the mixed raw material moisture becomes 8%. After granulation, the mixture was further granulated with a second drum mixer (diameter 5 m, length 18.5 m, rotation speed 4.8 rpm) to produce a sintered ore. There was no change in the raw material particle size after granulation shown in Table 2 before and after the addition of the waste activated carbon, and all the waste activated carbon was incorporated into the pseudo particles.

  The calorific value of coke is 8000 cal / g, and the calorific value of waste activated carbon is 3000 to 5000 cal / g. Therefore, when 1 g of waste activated carbon is added, the amount of powder coke added can be reduced by 0.4 to 0.6 g (average 0.5).

SiO ₂ , CaO, and Al ₂ O _{3 in} waste activated carbon are also effectively used as sintered ores. As shown in Table 5, the productivity and properties of the product sintered ore (strength, reduction index, reduced powdering index) did not change at all before and after the waste activated carbon, and the effectiveness of the present invention was proved. .

  In this example, the total amount of the waste activated carbon was added before the first drum mixer, but the same effect was obtained even when a part or all of the waste activated carbon was added before the second drum mixer.

It is the schematic which shows the waste activated carbon mixing apparatus in one Embodiment of this invention. It is the schematic which shows the waste toner supply apparatus which supplies waste toner to the said waste activated carbon supply apparatus.

Explanation of symbols

1 ... Waste activated carbon mixing device (waste activated carbon mixing means)
2 ... Sinter 7a ... 1st drum mixer (primary mixing device)
7b 2nd drum mixer (secondary mixing device)

Claims (2)

  Add waste activated carbon to the sintering raw material, add water and quick lime as needed to granulate the sintering raw material using a mixing device, form pseudo particles, and supply the raw material to the sintering machine, A waste activated carbon treatment method characterized in that waste activated carbon incorporated in pseudo-particles functions as a heat source and a reducing agent for ore, thereby facilitating the formation of a low-melting-point mineral melt and making it useful for the sintering reaction. A waste activated carbon mixing means for mixing the waste activated carbon with the sintered raw material, and a sintering machine for sintering the sintered raw material mixed with the waste activated carbon,
The waste activated carbon mixing means is characterized in that the waste activated carbon is added to the sintered raw material before the mixing device for granulating the waste activated carbon and the sintered raw material, and the waste activated carbon and the sintered raw material are granulated by the mixing device. Waste activated carbon treatment equipment.

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