WO2017018263A1 - Desulfurizing agent, method for desulfurizing molten iron and method for producing molten iron - Google Patents
Desulfurizing agent, method for desulfurizing molten iron and method for producing molten iron Download PDFInfo
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- WO2017018263A1 WO2017018263A1 PCT/JP2016/071071 JP2016071071W WO2017018263A1 WO 2017018263 A1 WO2017018263 A1 WO 2017018263A1 JP 2016071071 W JP2016071071 W JP 2016071071W WO 2017018263 A1 WO2017018263 A1 WO 2017018263A1
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- Prior art keywords
- desulfurization
- hot metal
- agent
- desulfurizing agent
- quicklime
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C1/00—Refining of pig-iron; Cast iron
- C21C1/02—Dephosphorising or desulfurising
- C21C1/025—Agents used for dephosphorising or desulfurising
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/0037—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00 by injecting powdered material
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/04—Removing impurities by adding a treating agent
- C21C7/064—Dephosphorising; Desulfurising
- C21C7/0645—Agents used for dephosphorising or desulfurising
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F27—FURNACES; KILNS; OVENS; RETORTS
- F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
- F27D27/00—Stirring devices for molten material
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F27—FURNACES; KILNS; OVENS; RETORTS
- F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
- F27D3/00—Charging; Discharging; Manipulation of charge
- F27D3/18—Charging particulate material using a fluid carrier
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F27—FURNACES; KILNS; OVENS; RETORTS
- F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
- F27D3/00—Charging; Discharging; Manipulation of charge
- F27D3/18—Charging particulate material using a fluid carrier
- F27D2003/185—Conveying particles in a conduct using a fluid
Definitions
- the present invention relates to a desulfurizing agent, a hot metal desulfurization method, and a hot metal manufacturing method.
- hot metal discharged from the blast furnace usually contains a high concentration of sulfur (S) that adversely affects the quality of the steel.
- S sulfur
- various hot metal pretreatments and molten steel desulfurization are performed according to the required quality.
- hot metal desulfurization of hot metal also called “hot metal desulfurization”
- an injection desulfurization method in which desulfurization is performed by blowing a desulfurizing agent into the hot metal, or a desulfurization agent is added to the hot metal stirred by a stirring blade A method such as a mechanical stirring type desulfurization method in which desulfurization is performed by using a known method is known.
- a desulfurization agent mainly composed of cheap quick lime is used as a refining agent in any of the methods, and the desulfurization reaction proceeds according to the reaction formula shown in the formula (1).
- a method using a solvent such as fluorite (CaF 2 ) or an alumina-based solvent for the purpose of improving reaction efficiency by promoting hatching of quicklime is known.
- a solvent such as fluorite (CaF 2 ) or an alumina-based solvent
- 95 wt% CaO-5 wt% CaF 2 is widely used as a desulfurizing agent mixed with a solvent.
- these medium solvents are generally expensive, increasing the mixing ratio of the medium solvent in the desulfurizing agent causes an increase in the cost of the desulfurizing agent.
- the CaO concentration in the desulfurizing agent is lowered, there is a concern that the reaction efficiency of the desulfurizing agent is lowered.
- calcium carbide-based and soda-based desulfurization agents have been put into practical use, both of which have advantages and disadvantages.
- Calcium carbide-based desulfurization agents have a strong desulfurization ability, but have problems such as the generation of acetylene gas in the post-treatment of slag produced by the desulfurization treatment.
- calcium carbide-based desulfurization agents are also dangerous and difficult to handle.
- soda-based desulfurization agents are relatively inexpensive, they are highly alkaline and thus have a great influence on refractories such as furnaces and containers. In addition, since the soda-based desulfurization agent contains Na in the exhaust gas, it needs to be removed.
- a soda-based desulfurization agent has a high Na 2 O content in the slag, there are restrictions on its reuse in cement and the like. For this reason, it cannot be said that it is a desirable desulfurization agent like fluorine from the influence on the environment.
- a method using metal Mg as a desulfurization agent is also well known. Metal Mg easily reacts with S in the hot metal to produce MgS.
- the boiling point is as low as 1100 ° C., there is a risk that the hot metal vaporizes vigorously in the hot metal at 1250 ° C. to 1500 ° C. and the hot metal is scattered.
- the generated Mg vapor is not sufficiently contributed to the desulfurization reaction and is diffused into the atmosphere, so that the efficiency is poor. Furthermore, since metal Mg is very expensive, it causes an increase in cost for the desulfurization treatment.
- Patent Documents 2 and 3 disclose methods for controlling density, specific surface area, pore diameter capacity, and the like as lime properties in hot metal desulfurization by injection desulfurization. According to Patent Documents 2 and 3, by controlling these lime properties, the rising speed of the desulfurizing agent blown into the hot metal can be controlled (lowered), and the reaction between the hot metal and the desulfurizing agent is promoted. be able to.
- Patent Documents 2 and 3 are directed to the injection desulfurization method as the hot metal desulfurization method, and are not the optimal lime property in the mechanical stirring desulfurization method.
- the particle size of the target desulfurization agent is as small as 200 ⁇ m or less.
- a desulfurizing agent having a large particle size is used from the viewpoint of securing the addition yield.
- a method for securing the reaction interface area using such a desulfurizing agent having a large particle size is no mention of a method for securing the reaction interface area using such a desulfurizing agent having a large particle size.
- a powdery desulfurizing agent added to the hot metal bath surface is usually entrained in the hot metal, and the desulfurizing agent reacts with S in the hot metal.
- the desulfurization efficiency is lowered because the reaction interfacial area is reduced by agglomeration of the desulfurizing agent.
- the slag after the desulfurization treatment becomes agglomerated particles of several mm to several tens mm.
- a method for improving the reaction efficiency in the mechanical stirring type desulfurization method a method of projecting a powdered desulfurization agent onto the bath surface (also referred to as a projection method) is known. Since the projection method suppresses the aggregation of the desulfurizing agent when being entrained in the hot metal as compared with the upper addition method, the substantial reaction interface area is increased and the desulfurization ability can be improved. However, even in such a projection method, aggregation of the projected desulfurizing agent still proceeds, so that the reaction interface area of the desulfurizing agent itself could not be fully utilized.
- Patent Documents 4 and 5 disclose a method of projecting a desulfurizing agent using a carrier gas.
- the desulfurization agent itself can be prevented from agglomerating by promoting the penetration of the desulfurization agent into the hot metal.
- no consideration is given to the properties of quicklime, so a technique for further improving the desulfurization efficiency of quicklime is required from the viewpoint of the lime properties.
- JP-A-8-268717 Japanese Patent No. 5101988 JP 62-56509 A Japanese Patent No. 5045031 Japanese Patent No. 5195737
- the present invention has been made paying attention to the above-mentioned problems, and aims to provide a desulfurization agent, a hot metal desulfurization method, and a hot metal manufacturing method that are excellent in desulfurization efficiency and can reduce the cost of desulfurization treatment. Yes.
- a desulfurization agent used for hot metal desulfurization and the total pore volume, which is the sum of the volume of pores having a pore diameter of 0.5 ⁇ m or more and 10 ⁇ m or less, is 0.1 mL / g or more.
- a desulfurizing agent characterized in that it comprises according to one aspect of the present invention, when the hot metal is desulfurized with a mechanically stirring desulfurization apparatus, the total pore volume, which is the sum of the pore volumes having a pore diameter of 0.5 ⁇ m or more and 10 ⁇ m or less, is 0.00.
- a hot metal desulfurization method characterized by using a desulfurization agent containing powdered quicklime with an average particle size of 210 ⁇ m to 500 ⁇ m. According to one aspect of the present invention, there is provided a hot metal production method using the hot metal desulfurization method.
- a desulfurization agent for reducing the cost of desulfurization treatment.
- FIG. 1 shows the mechanical stirring type desulfurization apparatus 1 used in the first test
- Table 1 shows the conditions of the apparatus and test method in which the first test was performed.
- the mechanical stirring type desulfurization apparatus 1 is a refining apparatus for desulfurizing a hot metal 3 accommodated in a hot metal ladle 2.
- the hot metal ladle 2 is placed at the processing position while being placed on the carriage 4.
- the ladle diameter of the hot metal ladle 2 is 4 m
- the weight of the hot metal 3 is 300 t / ch
- the temperature of the hot metal 3 is 1280 ° C. or higher and 1330 ° C. or lower
- the S concentration ([[ S]) was set to 0.025 wt% or more and 0.035 wt% or less.
- ch charge is a unit indicating the number of desulfurization processes performed for each hot metal ladle 2 by the mechanical stirring desulfurization apparatus 1, and 300 t / ch is the weight of the hot metal 3 processed in one desulfurization process ( The weight of the hot metal 3 accommodated in the hot metal ladle 2 is 300 t.
- the mechanical stirring desulfurization apparatus 1 includes a stirring blade (impeller) 5, a projection unit 6, and an upper addition unit 7.
- the stirring blade 5 is a refractory stirrer, and is connected to a shaft at the upper end in the vertical direction (vertical direction with respect to the plane of FIG. 1), and protrudes in a direction perpendicular to the central axis centering on this shaft. With wings.
- the upper end side of the shaft of the stirring blade 5 is connected to a rotating device and a lifting device (not shown).
- the stirring blade 5 rotates around the shaft when the shaft receives rotational driving from the rotating device.
- the stirring blade 5 is configured to be vertically movable by the lifting operation of the lifting device.
- the projection unit 6 includes a hopper 8, a rotary feeder 9, and a lance 10.
- the hopper 8 contains a desulfurizing agent.
- the rotary feeder 9 cuts out the desulfurizing agent accommodated in the hopper 8 at a predetermined cutting speed and supplies it to the lance 10.
- the lance 10 is a lance of 65A, and is arranged above the bath surface of the hot metal 3 so as to extend in the vertical direction.
- the lance 10 sprays the desulfurizing agent on the bath surface of the hot metal 3 by injecting the desulfurizing agent cut out from the rotary feeder 9 together with nitrogen which is a carrier gas supplied from a carrier gas supply device (not shown).
- the upper addition means 7 includes a hopper 11, a rotary feeder 12, and a charging chute 13.
- the hopper 11 contains a desulfurizing agent.
- the rotary feeder 12 cuts out the desulfurizing agent accommodated in the hopper 11 at a predetermined cutting speed and supplies it to the charging chute 13.
- the lower end of the charging chute 13 is arranged above the bath surface of the hot metal 3, and the desulfurizing agent supplied from the rotary feeder 12 is dropped freely from the tip to be poured into the bath surface of the hot metal 3.
- the desulfurizing agent was added to the hot metal 3 by any one of the addition method using the projection means 6 or the upper addition method using the upper addition means 7 to perform the desulfurization treatment.
- the flow rate of nitrogen gas was set to 0 Nm 3 / min to 7 Nm 3 / min, and the desulfurizing agent was added at an addition rate of 200 kg / min.
- the desulfurization agent was added at an addition rate of 1000 kg / min.
- the desulfurization agent is only powdered quicklime, and desulfurization treatment is performed without adding additives other than components inevitably contained in the quicklime, and 5 kg is applied by the projection method or the upper addition method. / T (addition amount per ton of hot metal) was added. Furthermore, in order to investigate the relationship between the total pore volume of quicklime and the desulfurization rate (the ratio of the amount of change in the S concentration before and after the treatment with respect to the S concentration before the treatment) and the relationship between the particle size of the quicklime and the desulfurization rate, The desulfurization treatment was performed under the conditions in which the total pore volume of quicklime or the particle size of quicklime was changed.
- the total pore volume of quicklime is calculated from the measured pore size distribution.
- the method for measuring the pore size distribution is as follows. First, quick lime was dried at 120 ° C. for 4 hours as a pretreatment. Next, using an Autopore IV9520 manufactured by Micromerites, the pore distribution of the dried quicklime having a pore diameter of about 0.0036 ⁇ m to 200 ⁇ m was obtained by mercury porosimetry, and a cumulative pore volume curve was calculated. Further, the total pore volume of pores having a diameter of 0.5 ⁇ m to 10 ⁇ m was determined from the calculated cumulative pore volume curve. The pore diameter was calculated using the Washburn equation (equation (2)).
- the particle diameter is an average particle diameter, and a predetermined average particle diameter is obtained by sieving the desulfurizing agent.
- the method for measuring the average particle size of the desulfurizing agent is as follows. First, 500 g of a desulfurizing agent is collected at the time of shipment from the manufacturer or when the hopper 8 is loaded. Subsequently, the collected desulfurizing agent was sieved into 9 stages of 45 ⁇ m or less, 45 ⁇ m to 75 ⁇ m, 75 ⁇ m to 100 ⁇ m, 100 ⁇ m to 125 ⁇ m, 125 ⁇ m to 150 ⁇ m, 150 ⁇ m to 300 ⁇ m, 300 ⁇ m to 500 ⁇ m, 500 ⁇ m to 1000 ⁇ m, 1000 ⁇ m or more.
- the average particle diameter was calculated by calculating the weight ratio of the formula (3) for the sieved desulfurizing agent.
- D a is an average particle diameter (mm)
- d i is an average particle diameter (medium value of sieve mesh) (mm) in each particle diameter range
- w i is a desulfurizing agent on each sieve. The weight (kg) is shown.
- the relationship between the total pore volume, which is the sum of the volumes of pores having a pore diameter of 0.5 ⁇ m or more and 10 ⁇ m or less, and the desulfurization rate when the projection method or the top addition method is used is shown. It is shown in 2.
- the particle size of the desulfurization agent was 1 mm or less.
- the desulfurization rate is remarkably increased when the total pore volume having a pore diameter of 0.5 ⁇ m or more and 10 ⁇ m or less is 0.1 mL / g or more. It was confirmed that a high desulfurization rate of 80% or more was obtained.
- the cost for improving the desulfurization rate was increased by using the projection method as compared with the upper addition method.
- FIG. 3 shows the relationship between the average particle size of the desulfurizing agent and the desulfurization rate when the projection method or the top addition method is used.
- the total pore volume having a pore diameter of 0.5 ⁇ m or more and 10 ⁇ m or less was 0.2 mL / g.
- the desulfurization rate was remarkably increased when the average particle size of the desulfurizing agent was in the range of 210 ⁇ m or more and 500 ⁇ m or less.
- the desulfurization rate was further increased when the average particle size of the desulfurizing agent was 230 ⁇ m or more.
- the cost for improving the desulfurization rate was increased by using the projection method as compared with the upper addition method.
- At least one of the top addition method and the projection method is generally used as a desulfurization agent addition method in the mechanical stirring desulfurization method.
- a desulfurization agent addition method in the mechanical stirring desulfurization method, unlike the injection desulfurization method in which the added desulfurizing agent completely enters the hot metal, it is difficult to add the small-diameter desulfurization agent into the hot metal with a high yield.
- the particle size of the desulfurizing agent to be added is important for improving the yield.
- a desulfurization agent with a small particle size is used, and if this desulfurization agent can penetrate into the hot metal, it is possible to secure a reaction interface area with the hot metal, thus improving the desulfurization reaction efficiency.
- the desulfurization agent having a small particle diameter becomes difficult to penetrate into the hot metal as the particle diameter becomes small, there is a high possibility that it will not contribute to the reaction even if it is added.
- the particle size of the desulfurizing agent to be added is increased, it is advantageous for penetration into the hot metal and the yield is improved, but the reaction interfacial area is reduced, which is disadvantageous from the viewpoint of desulfurization reaction. For this reason, in order to promote the reaction while ensuring the yield to the hot metal, it is important to ensure both an appropriate particle size of the desulfurizing agent and increase the reaction efficiency.
- the inventors have determined that the pore diameter is 0.5 ⁇ m or more and 10 ⁇ m or less in order to improve the desulfurization efficiency in the mechanical stirring desulfurization method using quick lime as a desulfurizing agent. It was found that the presence of pores is important, and it is important to use a desulfurization agent having a total pore volume of 0.1 mL / g or more. Furthermore, it has been found that by using a desulfurizing agent having an average particle size of 210 ⁇ m or more and 500 ⁇ m or less, an appropriate particle size for improving the yield when added to molten iron can be secured. Thus, desulfurization efficiency can be further improved by controlling the average particle diameter in addition to the pores.
- the present inventors performed desulfurization treatment under various stirring conditions as a second test in order to investigate the influence of the stirring conditions on the desulfurization rate in the projection method.
- the desulfurizing agent is only powdery quick lime as in the first test, the total pore volume having a pore diameter of 0.5 ⁇ m or more and 10 ⁇ m or less is 0.1 mL / g or more, and the particle diameter is 2 mm.
- the following quicklime was used.
- the addition amount of the desulfurization agent was a fixed amount of 5 kg / t, and the desulfurization treatment was performed without adding the additive other than being inevitably contained in the lime.
- the desulfurization treatment was performed using the mechanical stirring desulfurization apparatus 1 shown in FIG.
- the 2nd test when adding a desulfurization agent, only the projection means 6 was used, and the addition conditions of the desulfurization agent were made the same as the 1st test.
- the influence of these stirring conditions on the desulfurization rate was investigated by changing the bath surface position of the hot metal 3 to which the desulfurizing agent was sprayed and the rotation speed of the stirring blade 5.
- the desulfurization rate was different depending on the number of rotations of the stirring blade 5 and the spraying position of the desulfurizing agent, but these were the flow rates in the horizontal direction of the bath surface of the hot metal 3 at the position where the desulfurizing agent was sprayed. I was able to organize it.
- the horizontal flow velocity is the flow velocity in the horizontal tangential direction of the swirling flow generated by mechanical stirring at the position where the desulfurizing agent is sprayed onto the bath surface of the molten iron 3.
- FIG. 4 shows the relationship between the horizontal flow velocity of the bath surface and the desulfurization rate. As shown in FIG.
- the hot metal 3 is desulfurized using the mechanical stirring desulfurization apparatus 1 shown in FIG.
- the mechanical agitation desulfurization apparatus 1 includes a lid (not shown) that covers the upper opening of the hot metal ladle 2 and an exhaust duct (not shown) that is provided on the lid and is connected to an exhaust device (not shown). Gases and dust generated during the desulfurization process are discharged to the exhaust device through the exhaust duct.
- the hot metal ladle 2 in which the hot metal 3 is accommodated is placed on the cart 4, and the cart 4 moves until the stirring blade 5 reaches a predetermined position with respect to the hot metal pan 2.
- the stirring blade 5 is lowered by the lifting device, so that the stirring blade 5 is immersed in the hot metal 3.
- the stirring blade 5 is rotated by a rotating device, and the rotation speed is increased until a predetermined rotation speed is reached.
- generated gas and dust are discharged from the exhaust duct by the exhaust device.
- the desulfurizing agent is added to the hot metal 3 by the projection means 6 or the upper addition means 7.
- the desulfurization agent is quick lime having a total pore volume of 0.1 mL / g or more and an average particle size of 210 ⁇ m or more and 500 ⁇ m or less, which is the sum of the pores having a pore diameter of 0.5 ⁇ m or more and 10 ⁇ m or less.
- the minimum value of the particle size of quicklime is preferably 40 ⁇ m or more in consideration of scattering at the time of addition.
- the quicklime may be calcined in any furnace such as a kiln furnace, a Merz furnace, or a Beckenbach furnace.
- the desulfurizing agent cut out by the rotary feeder 9 is added to the hot metal 3 by being blown into the bath surface of the hot metal 3 from the lance 10 together with a carrier gas such as nitrogen. At this time, it is preferable that the desulfurizing agent is blown into a position where the horizontal flow velocity on the bath surface of the molten iron 3 is 1.1 m / s or more and 11.9 m / s or less. The position where the flow velocity on the bath surface falls within the above range is calculated in advance from the stirring conditions such as the rotational speed of the stirring blade 5 and the spraying position of the desulfurizing agent.
- the desulfurizing agent cut out by the rotary feeder 9 is added to the bath surface of the hot metal 3 through the charging chute 13.
- the hot metal 3 is stirred by the stirring blade 5 until a predetermined time elapses. Thereafter, the rotation speed decreases until the rotation of the stirring blade 5 is stopped by the rotating device, and after the rotation is stopped, the stirring blade 5 is raised by the lifting device. Next, the slag generated by the desulfurization process floats, covers the bath surface of the molten iron 3, and becomes stationary, thereby completing the desulfurization process. Thereby, the hot metal 3 having a desired S concentration is manufactured.
- the desulfurizing agent may be a mixture of quick lime whose total pore volume and particle size are within the above ranges and quick lime whose total pore volume and particle size are outside the above ranges.
- the desulfurizing agent may be added with a solvent medium such as alumina in addition to quick lime whose total pore volume and particle size are within the above ranges.
- the desulfurization agent which concerns on this invention does not contain the solvent which has at least 1 eluting element among fluorine, sodium, and potassium.
- the desulfurization agent is used as the refining agent when performing the desulfurization treatment, but the present invention is not limited to this example.
- a refining agent that further accelerates the desulfurization reaction an aluminum dross powder containing metal Al or a deoxidizer such as metal Al may be added.
- the deoxidizing agent may be stored in a hopper different from the desulfurizing agent, and may be added to the hot metal 3 through the charging chute 13 after being cut out from the hopper.
- a medium solvent such as fluorite or soda ash may be added as a refining agent.
- the medium solvent may be added in a state of being mixed with the desulfurizing agent in advance, or after being stored in a hopper different from the desulfurizing agent and cut out from the hopper, the hot metal 3 is supplied via the charging chute 13. May be added.
- the projection means 6 was set as the structure provided with one lance 10, this invention is not limited to this example.
- two or more lances 10 may be provided.
- the desulfurization agent was set as the structure used for the mechanical stirring type hot metal desulfurization method, this invention is not limited to this example.
- quick lime having a total pore volume of 0.1 mL / g or more which is the sum of the volume of pores having a pore diameter of 0.5 ⁇ m or more and 10 ⁇ m or less, is used as the desulfurization agent, as shown in FIG.
- the desulfurization rate increases remarkably as the interfacial area increases.
- the desulfurizing agent according to the present invention may be used in a desulfurization treatment method other than the mechanical stirring type hot metal desulfurization method.
- the desulfurizing agent according to one aspect of the present invention is a desulfurizing agent used for hot metal desulfurization, and has a total pore volume of 0, which is the sum of the pore volumes with a pore diameter of 0.5 ⁇ m to 10 ⁇ m. Contains 1 mL / g or more of quicklime.
- the desulfurization efficiency by quick lime can be improved by setting the total pore volume of quick lime in the above range. This makes it possible to improve production efficiency by shortening the desulfurization time, reduce temperature loss and process costs, and reduce the amount of dust and slag generated with the desulfurization process.
- the cost for the refining agent can be reduced and handling is easy as compared with a desulfurization agent other than a CaO-based one having high reaction efficiency.
- the present invention can be applied to both the addition method and the projection method in the mechanical stirring type desulfurization method.
- quick lime is in the form of a powder having an average particle size of 210 ⁇ m or more and 500 ⁇ m or less, and is used in a mechanical stirring type hot metal desulfurization method.
- the desulfurization efficiency by quicklime can be improved more by making the average particle diameter of quicklime into the said range.
- the desulfurization efficiency improvement effect by the quick lime of the said structure can be acquired more effectively by using a desulfurization agent for the mechanical stirring type hot metal desulfurization method.
- quick lime has an average particle size of 230 ⁇ m or more and 500 ⁇ m or less.
- the desulfurization efficiency can be further improved as compared with the configuration of (2) above.
- at least any one of fluorine, potassium and sodium is not substantially contained.
- the state in which at least one element of fluorine, potassium, and sodium is substantially not included means that at least one element is included by intentional addition, except for inevitable traces of contamination. That is not.
- the amount of expensive medium solvent used is reduced, and the cost required for the refining agent in the desulfurization treatment can be reduced.
- the slag after the desulfurization treatment can be used effectively.
- it does not contain sodium it is not necessary to remove Na from the exhaust gas, and the refractory cost can be reduced.
- the cost for the refining agent can be reduced, and handling becomes easy.
- the desulfurizing agent may include components inevitably contained in quicklime.
- the medium solvent which has eluting elements such as sodium and potassium
- the usage-amount of an expensive medium solvent can be reduced and the cost concerning the refining agent in a desulfurization process can be reduced.
- the slag after the desulfurization treatment can be used effectively.
- it does not contain sodium it is not necessary to remove Na from the exhaust gas, and the refractory cost can be reduced.
- the hot metal desulfurization method is the sum of the pore volumes at which the pore diameter becomes 0.5 ⁇ m or more and 10 ⁇ m or less when the hot metal 3 is desulfurized by the mechanical stirring desulfurization apparatus 1.
- a desulfurization agent containing powdered quicklime having a total pore volume of 0.1 mL / g or more and an average particle diameter of 210 ⁇ m or more and 500 ⁇ m or less is used.
- quick lime has an average particle size of 230 ⁇ m or more and 500 ⁇ m or less. According to the configuration of the above (7), the same effect as the configuration of the above (3) can be obtained.
- the mechanical stirring type desulfurization apparatus 1 includes a stirring blade 5 for stirring the hot metal 3 and a desulfurizing agent on the bath surface of the hot metal 3 from above the hot metal 3 together with a carrier gas.
- the hot metal 3 is desulfurized, the hot metal is stirred using the stirring blade 5 and the hot metal 3 is stirred to desulfurize the bath surface using the upper blow lance 10. Spray the agent.
- the improvement effect of the desulfurization efficiency of quicklime can be enlarged more compared with the case where a desulfurization agent is added using the upper addition method.
- Example 1 the hot metal 3 was desulfurized using the hot metal desulfurization method according to the above embodiment, using the mechanical stirring desulfurization apparatus 1 shown in FIG.
- the hot metal 3 subjected to the desulfurization treatment was obtained by performing two-stage desiliconization treatment in the hot metal ladle, which is a blast furnace casting floor and a receiving vessel, after leaving the blast furnace.
- Example 1 desulfurization treatment was performed under a plurality of conditions using a desulfurizing agent in which the total pore volume, particle size, and ratio of quicklime were changed within the range of the above embodiment. Furthermore, in Example 1, the addition amount of the desulfurization agent is a constant amount of 5 kg / t, and when adding the desulfurization agent, either the projection method by the projection means 6 or the upper addition method by the upper addition means 7 is used. The desulfurization treatment was carried out under a plurality of conditions using. The desulfurization agent addition conditions and stirring conditions were the same as in the first test shown in Table 1. In any addition method of the desulfurizing agent, the position of the bath surface to which the desulfurizing agent is added is the same position. And desulfurization efficiency was evaluated by calculating a desulfurization rate from the S concentration of the hot metal 3 measured before and after the desulfurization treatment.
- Example 1 as a comparative example, the desulfurization treatment was performed under the conditions using the injection desulfurization method, the total pore volume of quick lime, and the average particle diameter being different from the range of the above embodiment.
- the desulfurization efficiency was evaluated.
- Table 2 shows the test level and desulfurization efficiency evaluation results in Example 1.
- the ratio (%) of quicklime indicates the ratio of quicklime that has a pore diameter of 0.5 ⁇ m or more and 10 ⁇ m or less and a particle diameter of 2 mm or less among the quicklime that is a desulfurization agent.
- 0.5-10 ⁇ m pore total volume (mL / g) represents the total pore volume, which is the sum of the volumes of pores having a pore diameter of 0.5 ⁇ m or more and 10 ⁇ m or less.
- the average pore diameter of the quicklime used was 0.1 ⁇ m to 0.3 ⁇ m.
- Example 2 when the addition method of the desulfurizing agent was the projection method, the influence of the stirring conditions on the desulfurization efficiency was investigated.
- a desulfurization agent was added using the projection method in the same manner as in Examples 1-1 to 1-15, and the sum of the total pore volumes, the particle diameters, and the stirring conditions of quick lime as a desulfurization agent were changed.
- the desulfurization treatment was performed under the conditions of: Table 3 shows the test level and the evaluation result of the desulfurization efficiency in Example 2.
- the difference in the stirring conditions which is the difference in the number of revolutions of the stirring blade 5 and the spraying position of the desulfurizing agent, was arranged by the horizontal flow velocity on the bath surface of the hot metal 3 calculated from each condition.
- the horizontal flow velocity on the bath surface of the hot metal 3 at the position where the desulfurizing agent is sprayed is in the range of 1.1 m / s to 11.5 m / s. Under the conditions of 9, 2-15 to 2-19, it was confirmed that the desulfurization rate was 97% or higher, which was higher than other conditions.
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Abstract
Description
CaO+S →CaS+O ・・・(1) The hot metal discharged from the blast furnace usually contains a high concentration of sulfur (S) that adversely affects the quality of the steel. For this reason, in the steelmaking process, various hot metal pretreatments and molten steel desulfurization are performed according to the required quality. Among these, as hot metal desulfurization of hot metal (also called “hot metal desulfurization”), an injection desulfurization method in which desulfurization is performed by blowing a desulfurizing agent into the hot metal, or a desulfurization agent is added to the hot metal stirred by a stirring blade. A method such as a mechanical stirring type desulfurization method in which desulfurization is performed by using a known method is known. Further, in any of the hot metal desulfurization methods, a desulfurization agent mainly composed of cheap quick lime is used as a refining agent in any of the methods, and the desulfurization reaction proceeds according to the reaction formula shown in the formula (1).
CaO + S → CaS + O (1)
本発明の一態様によれば、機械攪拌式脱硫装置にて溶銑を脱硫処理する際に、細孔径が0.5μm以上10μm以下となる細孔の容積の和である全細孔容積が0.1mL/g以上であり、平均粒径が210μm以上500μm以下の粉状の生石灰を含む脱硫剤を用いることを特徴とする溶銑脱硫方法が提供される。
本発明の一態様によれば、上記溶銑脱硫方法を用いることを特徴とする溶銑の製造方法が提供される。 According to one aspect of the present invention, there is provided a desulfurization agent used for hot metal desulfurization, and the total pore volume, which is the sum of the volume of pores having a pore diameter of 0.5 μm or more and 10 μm or less, is 0.1 mL / g or more. There is provided a desulfurizing agent characterized in that it comprises
According to one aspect of the present invention, when the hot metal is desulfurized with a mechanically stirring desulfurization apparatus, the total pore volume, which is the sum of the pore volumes having a pore diameter of 0.5 μm or more and 10 μm or less, is 0.00. There is provided a hot metal desulfurization method characterized by using a desulfurization agent containing powdered quicklime with an average particle size of 210 μm to 500 μm.
According to one aspect of the present invention, there is provided a hot metal production method using the hot metal desulfurization method.
はじめに、本発明者らが本発明に至った経緯について説明する。本発明者らは、機械攪拌式脱硫法において、脱硫剤の特性(主に石灰性状)の観点から、各特性による脱硫効率への影響について鋭意研究を行った。その結果、比表面積、活性度などの様々な特性のうち、生石灰の細孔径分布および粒径の影響が大きく、特に細孔径の範囲が0.5μm以上10μm以下の細孔の全細孔容積が大きく影響することを知見した。図1に第1の試験に用いた機械攪拌式脱硫装置1、表1に第1の試験を実施した装置および試験方法の条件をそれぞれ示す。 In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of embodiments of the present invention. However, it will be apparent that one or more embodiments may be practiced without such specific details. In other instances, well-known structures and devices are schematically shown in order to simplify the drawing.
First, how the present inventors have reached the present invention will be described. In the mechanical stirring type desulfurization method, the present inventors have intensively studied the influence of each characteristic on the desulfurization efficiency from the viewpoint of the characteristics (mainly lime property) of the desulfurizing agent. As a result, among various characteristics such as specific surface area and activity, the influence of the pore size distribution and particle size of quicklime is large, and the total pore volume of pores having a pore size range of 0.5 μm to 10 μm is particularly large. It has been found that it has a significant effect. FIG. 1 shows the mechanical stirring
P×D =-4×σ×cosθ ・・・(2) The total pore volume of quicklime is calculated from the measured pore size distribution. The method for measuring the pore size distribution is as follows. First, quick lime was dried at 120 ° C. for 4 hours as a pretreatment. Next, using an Autopore IV9520 manufactured by Micromerites, the pore distribution of the dried quicklime having a pore diameter of about 0.0036 μm to 200 μm was obtained by mercury porosimetry, and a cumulative pore volume curve was calculated. Further, the total pore volume of pores having a diameter of 0.5 μm to 10 μm was determined from the calculated cumulative pore volume curve. The pore diameter was calculated using the Washburn equation (equation (2)). In equation (2), P is pressure, D is the pore diameter, σ is the surface tension of mercury (= 480 dynes / cm), and θ is the contact angle between mercury and the sample (= 140 degrees).
P × D = −4 × σ × cos θ (2)
第2の試験の結果として、浴面の水平方向の流速と脱硫率との関係を図4に示す。図4に示すように、脱硫剤を吹き付ける位置の浴面の水平方向の流速が1.1m/s以上11.9m/s以下の場合、脱硫反応がより促進されていることが確認できた。脱硫剤をキャリアガスと共に溶銑3の浴面に吹き付ける場合、固体の生石灰が溶銑3の中に侵入する条件として、溶銑3側の速度も重要な要素となることが考えられる。脱硫剤を吹き付ける位置の浴面の水平方向の流速が1.1m/sより遅い場合、溶銑3の中へ添加された脱硫剤が攪拌羽根5により生成した渦中へ移動することができずに、すぐに浴面へ浮上してしまい、脱硫剤と溶銑3とでの反応が促進されない。一方、脱硫剤を吹き付ける位置の浴面の水平方向の流速が11.9m/sよりも速い場合、脱硫剤の垂直方向の速度が溶銑3の水平方向の速度に負けてしまい、一部の脱硫剤が飛散している様子が観察された。このことから、粉状の脱硫剤を吹き付ける位置の浴面の水平方向の流速が1.1m/s以上11.5m/s以下の場合、細孔径容量を調整した効果が発揮され、より効率よく溶銑3の中へ脱硫剤を巻込むことが可能となったと考えられる。
なお、上述の一連の試験では、上記の細孔容積や粒径の条件を満たす生石灰のみを生石灰源として実験を行ったが、これらの細孔容積や粒径の条件を満たさない生石灰を一部混合して脱硫剤としても構わない。この場合は、本発明の細孔径容量の条件を満たす生石灰の混合率に応じた効果が得られる。 As the stirring conditions, the desulfurization rate was different depending on the number of rotations of the
As a result of the second test, FIG. 4 shows the relationship between the horizontal flow velocity of the bath surface and the desulfurization rate. As shown in FIG. 4, it was confirmed that the desulfurization reaction was further promoted when the flow velocity in the horizontal direction of the bath surface at the position where the desulfurizing agent was sprayed was 1.1 m / s or more and 11.9 m / s or less. When the desulfurizing agent is sprayed on the bath surface of the
In the series of tests described above, experiments were conducted using only quick lime satisfying the above pore volume and particle size conditions as a quick lime source, but some of the quick lime not satisfying these pore volume and particle size conditions were used. It may be mixed to be a desulfurizing agent. In this case, the effect according to the mixing ratio of quicklime satisfying the pore capacity capacity of the present invention can be obtained.
次に、上記知見に基づいた、本発明の一実施形態に係る脱硫剤、溶銑脱硫方法および溶銑の製造方法について説明する。本実施形態では、上記第1および第2の試験と同様に、図1に示す機械攪拌式脱硫装置1を用いて溶銑3の脱硫処理を行う。なお、機械攪拌式脱硫装置1は、溶銑鍋2の上部開口部を覆う蓋(不図示)や、この蓋に設けられ排気装置(不図示)に接続される排気ダクト(不図示)を有する。脱硫処理中に生じるガスやダストは、この排気ダクトを通じて排気装置へと排出される。 <Desulfurizing agent, hot metal desulfurization method and hot metal manufacturing method>
Next, a desulfurization agent, a hot metal desulfurization method, and a hot metal manufacturing method according to an embodiment of the present invention based on the above findings will be described. In the present embodiment, similarly to the first and second tests, the
以上で、特定の実施形態を参照して本発明を説明したが、これら説明によって発明を限定することを意図するものではない。本発明の説明を参照することにより、当業者には、開示された実施形態の種々の変形例とともに本発明の別の実施形態も明らかである。従って、特許請求の範囲は、本発明の範囲および要旨に含まれるこれらの変形例または実施形態も網羅すると解すべきである <Modification>
Although the present invention has been described above with reference to specific embodiments, it is not intended that the present invention be limited by these descriptions. From the description of the invention, other embodiments of the invention will be apparent to persons skilled in the art, along with various variations of the disclosed embodiments. Therefore, it is to be understood that the claims encompass these modifications and embodiments that fall within the scope and spirit of the present invention.
さらに、上記実施形態では、脱硫剤は機械攪拌式溶銑脱硫法に用いられる構成としたが、本発明はかかる例に限定されない。脱硫剤として、細孔径が0.5μm以上10μm以下となる細孔の容積の和である全細孔容積が0.1mL/g以上の生石灰を用いる場合には、図2に示すように、反応界面積が大きくなることで脱硫率が顕著に増加する。この効果は、機械攪拌式溶銑脱硫法だけでなく、例えば、インジェクション脱硫法といった、溶銑を脱硫処理する他の脱硫法においても有効なものとなる。このため、本発明に係る脱硫剤は、機械攪拌式溶銑脱硫法以外の脱硫処理の方法に用いられてもよい。 Furthermore, in the said embodiment, although the projection means 6 was set as the structure provided with one
Furthermore, in the said embodiment, although the desulfurization agent was set as the structure used for the mechanical stirring type hot metal desulfurization method, this invention is not limited to this example. When quick lime having a total pore volume of 0.1 mL / g or more, which is the sum of the volume of pores having a pore diameter of 0.5 μm or more and 10 μm or less, is used as the desulfurization agent, as shown in FIG. The desulfurization rate increases remarkably as the interfacial area increases. This effect is effective not only in the mechanical stirring type hot metal desulfurization method but also in other desulfurization methods for desulfurizing the hot metal, for example, an injection desulfurization method. Therefore, the desulfurizing agent according to the present invention may be used in a desulfurization treatment method other than the mechanical stirring type hot metal desulfurization method.
(1)本発明の一態様に係る脱硫剤は、溶銑脱硫に用いられる脱硫剤であって、細孔径が0.5μm以上10μm以下となる細孔の容積の和である全細孔容積が0.1mL/g以上の生石灰を含む。
上記(1)の構成によれば、生石灰の全細孔容積を上記範囲とすることにより、生石灰による脱硫効率を向上させることができる。これにより、脱硫処理時間の短縮による生産効率の向上、温度ロスの低減および処理コストの低減、ならびに脱硫処理に伴い発生するダストおよびスラグの発生量低減が可能となる。また、反応効率の高いCaO系以外の脱硫剤に比べ、精錬剤に掛かるコストを低減でき、取扱いも容易となる。さらに、機械攪拌式脱硫法における上添加法および投射法の両方の添加手段に対して適用することができる。 <Effect of embodiment>
(1) The desulfurizing agent according to one aspect of the present invention is a desulfurizing agent used for hot metal desulfurization, and has a total pore volume of 0, which is the sum of the pore volumes with a pore diameter of 0.5 μm to 10 μm. Contains 1 mL / g or more of quicklime.
According to the configuration of (1) above, the desulfurization efficiency by quick lime can be improved by setting the total pore volume of quick lime in the above range. This makes it possible to improve production efficiency by shortening the desulfurization time, reduce temperature loss and process costs, and reduce the amount of dust and slag generated with the desulfurization process. In addition, the cost for the refining agent can be reduced and handling is easy as compared with a desulfurization agent other than a CaO-based one having high reaction efficiency. Furthermore, the present invention can be applied to both the addition method and the projection method in the mechanical stirring type desulfurization method.
上記(2)の構成によれば、生石灰の平均粒径を上記範囲とすることで、生石灰による脱硫効率をより向上させることができる。また、脱硫剤を機械攪拌式溶銑脱硫法に用いることで、上記構成の生石灰による脱硫効率向上効果をより効果的に得ることができる。 (2) In the configuration of (1), quick lime is in the form of a powder having an average particle size of 210 μm or more and 500 μm or less, and is used in a mechanical stirring type hot metal desulfurization method.
According to the structure of said (2), the desulfurization efficiency by quicklime can be improved more by making the average particle diameter of quicklime into the said range. Moreover, the desulfurization efficiency improvement effect by the quick lime of the said structure can be acquired more effectively by using a desulfurization agent for the mechanical stirring type hot metal desulfurization method.
上記(3)の構成によれば、上記(2)の構成に比べ、脱硫効率をより向上させることができる。
(4)上記(1)~(3)のいずれかの構成において、実質的にフッ素、カリウムおよびナトリウムの少なくともいずれか一つが含まれない。ここで、フッ素、カリウムおよびナトリウムの少なくともいずれか一つの元素が実質的に含まれない状態とは、少なくともいずれか一つの元素が、不可避的な微量の混入を除いて、意図的な添加により含まれていないことをいう。 (3) In the configuration of (2) above, quick lime has an average particle size of 230 μm or more and 500 μm or less.
According to the configuration of (3) above, the desulfurization efficiency can be further improved as compared with the configuration of (2) above.
(4) In any one of the constitutions (1) to (3), at least any one of fluorine, potassium and sodium is not substantially contained. Here, the state in which at least one element of fluorine, potassium, and sodium is substantially not included means that at least one element is included by intentional addition, except for inevitable traces of contamination. That is not.
上記(5)の構成によれば、媒溶剤やCaO系以外の脱硫剤を用いることがないため、精錬剤に掛かるコストを大幅に低減することができる。また、ナトリウムやカリウム等の溶出元素を有する媒溶剤を含まないため、高価な媒溶剤の使用量が削減され、脱硫処理における精錬剤に掛かるコストを低減することができる。さらに、フッ素などの環境への影響が懸念される成分を含まないため、脱硫処理後のスラグを有効的に活用することができる。さらに、ナトリウムを含まないため、排ガス中からのNa除去処理の必要がなく、耐火物コストを低減することができる。 (5) In any one of the constitutions (1) to (3), it is composed only of quicklime. In addition to the CaO, the desulfurizing agent may include components inevitably contained in quicklime.
According to the configuration of the above (5), no desulfurization agent other than the solvent or CaO system is used, so that the cost for the refining agent can be greatly reduced. Moreover, since the medium solvent which has eluting elements, such as sodium and potassium, is not included, the usage-amount of an expensive medium solvent can be reduced and the cost concerning the refining agent in a desulfurization process can be reduced. Furthermore, since it does not contain components such as fluorine that are likely to affect the environment, the slag after the desulfurization treatment can be used effectively. Furthermore, since it does not contain sodium, it is not necessary to remove Na from the exhaust gas, and the refractory cost can be reduced.
上記(6)の構成によれば、上記(1)および(2)の構成と同様な効果を得ることができる。
(7)上記(6)の構成において、生石灰は、平均粒径が230μm以上500μm以下である。
上記(7)の構成によれば、上記(3)の構成と同様な効果を得ることができる。 (6) The hot metal desulfurization method according to one aspect of the present invention is the sum of the pore volumes at which the pore diameter becomes 0.5 μm or more and 10 μm or less when the
According to the configuration of (6), the same effects as those of the configurations (1) and (2) can be obtained.
(7) In the configuration of (6) above, quick lime has an average particle size of 230 μm or more and 500 μm or less.
According to the configuration of the above (7), the same effect as the configuration of the above (3) can be obtained.
上記(8)の構成によれば、上添加法を用いて脱硫剤を添加する場合に比べ、生石灰の脱硫効率の向上効果をより大きくすることができる。 (8) In the configuration of (6) or (7), the mechanical stirring
According to the structure of said (8), the improvement effect of the desulfurization efficiency of quicklime can be enlarged more compared with the case where a desulfurization agent is added using the upper addition method.
上記(9)の構成によれば、投射法によって脱硫剤を添加する場合において、脱硫効率をさらに向上させることができる。
(10)本発明の一態様に係る溶銑の製造方法は、上記(6)~(9)のいずれかの構成に記載の溶銑脱硫方法を用いる。
上記(10)の構成によれば、上記(6)~(9)の構成と同様な効果を得ることができる。 (9) In the configuration of (8) above, when the desulfurizing agent is sprayed on the bath surface, the horizontal flow velocity of the bath surface at the position where the desulfurizing agent is sprayed is 1.1 m / s or more and 11.5 m / s or less. To do.
According to the configuration of (9), the desulfurization efficiency can be further improved when the desulfurization agent is added by the projection method.
(10) The hot metal manufacturing method according to one aspect of the present invention uses the hot metal desulfurization method described in any one of the above (6) to (9).
According to the configuration of (10), the same effects as those of the configurations (6) to (9) can be obtained.
実施例1では、脱硫処理が行われる溶銑3には、高炉から出銑した後、高炉鋳床および受銑容器である溶銑鍋における2段階の脱珪処理を行ったものを用いた。脱硫処理前の溶銑3の組成は、事前の脱珪により[Si]=0.05wt%~0.10wt%、[C]=4.3wt%~4.6wt%、[Mn]=0.22wt%~0.41wt%、[P]=0.10wt%~0.13wt%、および[S]=0.025wt%~0.035wt%であった。脱硫処理前の溶銑3の温度は、1280℃~1330℃であった。 Next, examples performed by the present inventors will be described. In Example 1, the
In Example 1, the
表2に、実施例1における試験水準と脱硫効率の評価結果を示す。表2において、生石灰の比率(%)は、脱硫剤である生石灰のうち、細孔径が0.5μm以上10μm以下、且つ粒径が2mm以下となる生石灰の比率を示す。また、表2において、0.5-10μm細孔全容積(mL/g)は、細孔径が0.5μm以上10μm以下の細孔の容積の和である全細孔容積を示す。なお、用いた生石灰の平均細孔径は、0.1μm~0.3μmであった。 Furthermore, in Example 1, as a comparative example, the desulfurization treatment was performed under the conditions using the injection desulfurization method, the total pore volume of quick lime, and the average particle diameter being different from the range of the above embodiment. The desulfurization efficiency was evaluated.
Table 2 shows the test level and desulfurization efficiency evaluation results in Example 1. In Table 2, the ratio (%) of quicklime indicates the ratio of quicklime that has a pore diameter of 0.5 μm or more and 10 μm or less and a particle diameter of 2 mm or less among the quicklime that is a desulfurization agent. In Table 2, 0.5-10 μm pore total volume (mL / g) represents the total pore volume, which is the sum of the volumes of pores having a pore diameter of 0.5 μm or more and 10 μm or less. The average pore diameter of the quicklime used was 0.1 μm to 0.3 μm.
一方、細孔全容積の和または粒径のいずれかが上記実施形態の条件と異なる比較例1-1~1-12では、脱硫率が70%以下となり、実施例1-1~1-17に比べて低位となることが確認された。 As shown in Table 2, in Examples 1-1 to 1-17 in which the characteristics of quick lime, which is a desulfurizing agent, are the conditions of the above-described embodiment, a high desulfurization of 75% or more regardless of the method of adding the desulfurizing agent. It was confirmed that the rate was obtained. Further, the desulfurization rate tends to be higher in the conditions using the projection method in Examples 1-9 to 1-15 than in the conditions using the upper addition method in Examples 1-1 to 1-8. confirmed.
On the other hand, in Comparative Examples 1-1 to 1-12, in which either the total pore volume or the particle diameter is different from the conditions of the above embodiment, the desulfurization rate is 70% or less, and Examples 1-1 to 1-17 It was confirmed to be lower than
2 溶銑鍋
3 溶銑
4 台車
5 攪拌羽根
6 投射手段
7 上添加手段
8 ホッパー
9 ロータリーフィーダ
10 ランス
11 ホッパー
12 ロータリーフィーダ
13 投入シュート DESCRIPTION OF
Claims (10)
- 溶銑脱硫に用いられる脱硫剤であって、
細孔径が0.5μm以上10μm以下となる細孔の容積の和である全細孔容積が0.1mL/g以上の生石灰を含むことを特徴とする脱硫剤。 A desulfurization agent used for hot metal desulfurization,
A desulfurization agent comprising quick lime having a total pore volume of 0.1 mL / g or more, which is a sum of pore volumes having a pore diameter of 0.5 μm or more and 10 μm or less. - 前記生石灰は、平均粒径が210μm以上500μm以下の粉状のものであり、
機械攪拌式溶銑脱硫法に用いられることを特徴とする請求項1に記載の脱硫剤。 The quicklime is powdery with an average particle size of 210 μm or more and 500 μm or less,
The desulfurizing agent according to claim 1, wherein the desulfurizing agent is used in a mechanical stirring hot metal desulfurization method. - 前記生石灰は、平均粒径が230μm以上500μm以下であることを特徴とする請求項2に記載の脱硫剤。 The desulfurization agent according to claim 2, wherein the quicklime has an average particle size of 230 µm or more and 500 µm or less.
- 実質的にフッ素、カリウムおよびナトリウムの少なくともいずれか一つが含まれないことを特徴とする請求項1~3のいずれか1項に記載の脱硫剤。 The desulfurization agent according to any one of claims 1 to 3, wherein at least any one of fluorine, potassium and sodium is not substantially contained.
- 前記生石灰のみからなることを特徴とする請求項1~3のいずれか1項に記載の脱硫剤。 The desulfurization agent according to any one of claims 1 to 3, wherein the desulfurization agent comprises only the quicklime.
- 機械攪拌式脱硫装置にて溶銑を脱硫処理する際に、
細孔径が0.5μm以上10μm以下となる細孔の容積の和である全細孔容積が0.1mL/g以上であり、平均粒径が210μm以上500μm以下の粉状の生石灰を含む脱硫剤を用いることを特徴とする溶銑脱硫方法。 When hot metal is desulfurized with a mechanical stirring desulfurizer,
A desulfurization agent containing powdered quicklime having a total pore volume of 0.1 mL / g or more and an average particle diameter of 210 μm or more and 500 μm or less, which is the sum of the pores having a pore diameter of 0.5 μm or more and 10 μm or less A hot metal desulfurization method comprising using - 前記生石灰は、平均粒径が230μm以上500μm以下であることを特徴とする請求項6に記載の溶銑脱硫方法。 The hot metal desulphurization method according to claim 6, wherein the quicklime has an average particle size of 230 μm or more and 500 μm or less.
- 前記機械攪拌式脱硫装置は、前記溶銑を攪拌する攪拌羽根と、前記溶銑の上方より前記溶銑の浴面に前記脱硫剤をキャリアガスと共に吹き付ける上吹きランスとを備え、
前記溶銑の脱硫処理をする際に、
前記攪拌羽根を用いて前記溶銑を攪拌し、
前記溶銑が攪拌された状態で、前記上吹きランスを用いて前記浴面に前記脱硫剤を吹き付けることを特徴とする請求項6または7に記載の溶銑脱硫方法。 The mechanical stirring type desulfurization apparatus includes a stirring blade for stirring the hot metal, and an upper blowing lance for spraying the desulfurizing agent together with a carrier gas to the bath surface of the hot metal from above the hot metal,
When desulfurizing the hot metal,
Stir the hot metal using the stirring blade,
The hot metal desulfurization method according to claim 6 or 7, wherein the desulfurizing agent is sprayed onto the bath surface using the upper blowing lance in a state where the hot metal is stirred. - 前記脱硫剤を前記浴面に吹き付ける際に、前記脱硫剤が吹き付けられる位置の前記浴面の水平方向の流速を、1.1m/s以上11.5m/s以下とすることを特徴とする請求項8に記載の溶銑脱硫方法。 The horizontal flow velocity of the bath surface at a position where the desulfurizing agent is sprayed when spraying the desulfurizing agent on the bath surface is set to 1.1 m / s or more and 11.5 m / s or less. Item 9. The hot metal desulfurization method according to Item 8.
- 請求項6~9のいずれか1項に記載の溶銑脱硫方法を用いることを特徴とする溶銑の製造方法。 A hot metal production method using the hot metal desulfurization method according to any one of claims 6 to 9.
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EP16830368.3A EP3327150B1 (en) | 2015-07-24 | 2016-07-15 | Desulfurizing agent, method for desulfurizing molten iron and method for producing molten iron |
KR1020187001100A KR102142198B1 (en) | 2015-07-24 | 2016-07-15 | Desulfurizing agent, method for desulfurizing molten iron and method for producing molten iron |
JP2016570900A JP6156598B2 (en) | 2015-07-24 | 2016-07-15 | Desulfurizing agent, hot metal desulfurization method, and hot metal manufacturing method |
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