Method for preparing metallurgical dephosphorizing agent by synchronously gasifying effect of vaporizing flue gas of calcium-based reinforced metallurgical furnace and desulfurizing flue gas
Patent Information
- Application Number
- CN202510226922.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-27
- Publication Date
- 2026-08-28
AI Technical Summary
[0003]目前常见的脱硫方法有三种：一是使用碱性溶液(如氢氧化钠溶液)吸收煤气中的硫化氢，反应后在吸收塔内逆向接触，生成稳定的硫化物，但碱性溶液的价格较高，吸收后的溶液需要进一步处理，以去除生成的硫化物，可能会产生二次污染
[0021] 1. This application provides a method for simultaneously preparing a metallurgical dephosphorizing agent by enhancing the gasification effect of coal gasification in a calcium-based metallurgical furnace gasification flue and desulfurizing the flue gas. The method utilizes calcium-based materials to load and bond organic materials used for coal gasification in the metallurgical furnace gasification flue. These materials are then injected into the metallurgical furnace gasification flue using a spray system. The loaded calcium-based materials enhance the cracking and gasification of organic fuels during this process, promoting the cracking of large organic molecules, increasing calorific value, and facilitating the gasification reaction between carbon-containing organic materials and H2O/CO2 to generate CO. This improves CO recovery rate, increases CO2 conversion rate, reduces carbon emissions, enhances gas grade, improves energy utilization, and increases economic benefits.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of metallurgical energy conservation and environmental protection technology, specifically to a method for simultaneously preparing metallurgical dephosphorizing agents by improving the gasification effect of coal gasification in a calcium-based enhanced metallurgical furnace gasification flue and desulfurizing flue gas. Background Technology
[0002] The steelmaking process in metallurgical furnaces generates a large amount of high-temperature, dust-laden flue gas, which is toxic and explosive. Metallurgical gas is a combustible mixture of gases containing large amounts of CO and CO2 produced during the smelting process. When the conditions for gas recovery are met, metallurgical furnace flue gas can be recovered as metallurgical furnace gas. Coal gasification technology refers to the process of converting carbon and hydrogen in coal into syngas such as carbon monoxide and hydrogen through a specific flow path using a gasifying agent (carbon dioxide, oxygen, water vapor, hydrogen, etc.), thus transforming coal from a solid fuel to a gaseous fuel. During coal gasification, sulfur-containing gases are collected in the metallurgical gas. These sulfur-containing components affect the activity of the catalyst in the reaction, thereby affecting production quality. The released sulfur also causes environmental pollution; therefore, desulfurization of metallurgical flue gas is crucial.
[0003] Currently, there are three common desulfurization methods: First, using an alkaline solution (such as sodium hydroxide solution) to absorb hydrogen sulfide from coal gas. After the reaction, the gases react in a counter-current manner within the absorption tower to generate stable sulfides. However, alkaline solutions are expensive, and the absorbed solution requires further treatment to remove the generated sulfides, potentially causing secondary pollution. Second, utilizing metal oxides (such as iron oxide and zinc oxide) to adsorb and catalyze the oxidation reaction of gaseous sulfides. However, metal oxide catalysts may deactivate under high temperatures or acidic environments, requiring periodic replacement. Furthermore, the catalytic oxidation reaction requires specific temperatures and oxygen concentrations, making control difficult. The treatment and recycling of used catalysts is also an environmental issue that needs to be considered. Third, utilizing the catalytic and adsorption properties of activated carbon to oxidize sulfide into elemental sulfur, which is adsorbed onto the surface. However, activated carbon has a limited adsorption capacity and requires periodic replacement or regeneration.
[0004] In view of this, it is necessary to design an improved method for simultaneously preparing metallurgical dephosphorizing agents by improving the gasification effect of coal gasification in the gasification flue of a calcium-based enhanced metallurgical furnace and desulfurizing the flue gas, in order to solve the above problems. Summary of the Invention
[0005] In view of the technical problems existing in the background art, this application provides a method for simultaneously preparing metallurgical dephosphorizing agents by enhancing the coal gasification effect of the gasification duct of a calcium-based metallurgical furnace and desulfurizing the flue gas. The method involves uniformly loading calcium-based materials onto the coal gasification feedstock through a loading pretreatment process, and then injecting them into the gasification duct of the metallurgical furnace through a spraying system. Under the action of high-temperature flue gas, coal gasification is achieved. The loaded calcium-based materials play a role in enhancing the cracking and gasification of organic fuels during this process. At the same time, the sulfur-containing flue gas released by the organic fuels is solidified by the calcium-based materials. The solidification products enter the dust removal system with the flue dust. Simultaneously, the calcium-based materials react with the iron-containing components in the flue dust in the gasification duct of the metallurgical furnace to generate calcium ferrite with dephosphorization metallurgical properties. This calcium ferrite enters the dust removal system with the flue dust. The collected dust is separated and purified by magnetic separation and then used for the production of high-value-added dephosphorizing agents, providing an effective way for the sustainable and economical production of the metallurgical industry.
[0006] This application provides a method for simultaneously preparing a metallurgical dephosphorizing agent and improving the gasification effect of coal in a calcium-based enhanced metallurgical furnace gasification flue, including the following steps:
[0007] S1. Loading calcium-based material of a predetermined particle size with organic material for coal gasification, so that the calcium-based material is uniformly loaded onto the organic material;
[0008] S2. Using an injection device, the organic material loaded with calcium-based material in step S1 is injected into the high-temperature gasification flue of the metallurgical furnace for coal gasification treatment.
[0009] S3. Collect the metallurgical dust processed in step S2 through a dust removal system, and then separate and purify it by magnetic separation to obtain iron oxide and calcium ferrite;
[0010] S4. The iron oxide and calcium ferrite obtained in step S3 are used in the preparation of a metallurgical dephosphorizing agent.
[0011] As a further improvement to this application, the calcium-based material includes, but is not limited to, limestone, lime, dolomite, and hydrated lime, and the organic material includes, but is not limited to, coke, coal, graphite, biochar, and plastics.
[0012] As a further improvement of this application, the mass ratio of the calcium-based material to the organic material is (10-30%):(70-90%).
[0013] As a further improvement of this application, the particle size of the calcium-based material is less than 0.074 mm, and the particle size of the organic material is 0.074 to 0.150 mm.
[0014] As a further improvement to this application, the metallurgical furnace includes, but is not limited to, metallurgical shaft furnace, blast furnace, converter, electric furnace and refining furnace.
[0015] As a further improvement of this application, in step S2, the coal gasification treatment includes the process of converting organic materials and CO2 into CO, the solidification of sulfur-containing components, and the calcification transformation of iron-containing metallurgical dust.
[0016] As a further improvement to this application, the sulfur-containing components include, but are not limited to, SO2, H2S, and COS.
[0017] As a further improvement of this application, the calcium-based material solidifies the sulfur-containing component in the flue gas in the form of CaS and then enters the dust removal system.
[0018] As a further improvement to this application, the iron-containing metallurgical dust includes, but is not limited to, iron(II,III) oxide, iron oxide, ferrous oxide, and iron.
[0019] As a further improvement to this application, the calcification conversion products of the iron-containing metallurgical dust include, but are not limited to, calcium ferrite, magnesium-containing calcium ferrite, silicon-containing calcium ferrite, and composite calcium ferrite.
[0020] The beneficial effects of this application are as follows:
[0021] 1. This application provides a method for simultaneously preparing a metallurgical dephosphorizing agent by enhancing the gasification effect of coal gasification in a calcium-based metallurgical furnace gasification flue and desulfurizing the flue gas. The method utilizes calcium-based materials to load and bond organic materials used for coal gasification in the metallurgical furnace gasification flue. These materials are then injected into the metallurgical furnace gasification flue using a spray system. The loaded calcium-based materials enhance the cracking and gasification of organic fuels during this process, promoting the cracking of large organic molecules, increasing calorific value, and facilitating the gasification reaction between carbon-containing organic materials and H2O / CO2 to generate CO. This improves CO recovery rate, increases CO2 conversion rate, reduces carbon emissions, enhances gas grade, improves energy utilization, and increases economic benefits.
[0022] 2. The method provided in this application for simultaneously preparing metallurgical dephosphorizing agents and enhancing the gasification effect of coal gasification in a calcium-based enhanced metallurgical furnace gasification flue, involves solidifying sulfur-containing flue gas (SO2, H2S, COS, etc.) released from ore during organic material cracking and steel production into environmentally harmless and stable CaS using calcium-based materials. The generated sulfides enter the dust removal system along with the flue gas, realizing the sulfur emission during the metallurgical furnace recovery process, thereby effectively removing sulfur from the coal gas and reducing environmental pollution. The addition of calcium-based substances can improve the efficiency and environmental performance of the coal gasification process.
[0023] 3. The method for simultaneously preparing metallurgical dephosphorizing agents by improving the gasification effect of coal gasification in the gasification flue of a calcium-based metallurgical furnace and desulfurizing flue gas, provided in this application, involves the reaction of calcium-based materials with iron-containing components in the iron-containing dust in the gasification flue of the metallurgical furnace to generate calcium ferrite with excellent metallurgical properties. The calcium ferrite enters the dust removal system with the dust, and the collected dust is separated and purified by magnetic separation. It can then be used to prepare high-value-added dephosphorizing agents, further reducing production costs, achieving energy conservation and environmental protection, improving the quality of molten steel, increasing economic benefits, and reducing energy consumption.
[0024] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description
[0025] To more clearly illustrate the technical solutions of this application, the accompanying drawings used in this application will be briefly described below. Obviously, the drawings described below are merely some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without any creative effort.
[0026] Figure 1 This is a schematic diagram of the process for simultaneously preparing metallurgical dephosphorizing agents and achieving coal gasification effect in the gasification flue of a calcium-based enhanced metallurgical furnace in this embodiment of the application. Detailed Implementation
[0027] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.
[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.
[0029] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.
[0030] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).
[0031] Existing metallurgical flue gas desulfurization technologies suffer from problems such as high cost, complex operation, potential secondary pollution, easy catalyst deactivation requiring regular replacement, difficulty in control, and limited activated carbon adsorption capacity. These factors limit their efficiency and sustainability in practical applications, thus necessitating the development of more efficient, economical, and environmentally friendly improvement methods.
[0032] To address the technical problems of low desulfurization efficiency, high cost, and complex operation in existing metallurgical furnace gasification flue gasification processes, this application provides a method for simultaneously preparing metallurgical dephosphorizing agents by enhancing the coal gasification effect of a calcium-based metallurgical furnace gasification flue and simultaneously preparing flue gas desulfurization. This method involves loading and combining calcium-based materials with organic materials, then injecting the mixture into the high-temperature gasification flue of the metallurgical furnace. This achieves simultaneous coal gasification and flue gas desulfurization, thereby improving coal gasification efficiency, efficiently removing sulfides, reducing environmental pollution, and simultaneously preparing highly active metallurgical dephosphorizing agents.
[0033] This application provides a method for simultaneously preparing a metallurgical dephosphorizing agent and improving the gasification effect of coal in a calcium-based enhanced metallurgical furnace gasification flue, as well as for flue gas desulfurization, including the following steps:
[0034] S1. Loading calcium-based material of a predetermined particle size with organic material for coal gasification to ensure that the calcium-based material is uniformly loaded onto the organic material;
[0035] S2. Using an injection device, the organic material loaded with calcium-based material in step S1 is injected into the high-temperature gasification flue of the metallurgical furnace for coal gasification treatment.
[0036] S3. Collect the metallurgical dust processed in step S2 through a dust removal system, and then separate and purify it by magnetic separation to obtain iron oxide and calcium ferrite;
[0037] S4. Use the iron oxide and calcium ferrite obtained in step S3 to prepare a metallurgical dephosphorizing agent.
[0038] In the technical solution of this application embodiment, calcium-based materials are used to load and bind organic materials used for coal gasification in the gasification flue of a metallurgical furnace, so as to simultaneously achieve the goals of enhancing the coal gasification effect, reducing carbon dioxide and sulfur emissions from the flue gas, and calcifying and converting metallurgical furnace dust. Loading with calcium-based materials enhances the gasification reaction of organic materials at high temperatures, promotes carbon conversion, and improves the overall efficiency of coal gasification. Using an injection device, the calcium-based loaded organic materials are fed into the high-temperature gasification flue of the metallurgical furnace, allowing for desulfurization reactions to occur simultaneously with coal gasification. Under high-temperature conditions, the organic materials undergo pyrolysis and gasification to generate CO, while the calcium-based materials react with sulfur components in the flue gas to generate solid calcium sulfide, thus achieving desulfurization. By collecting and processing the metallurgical dust after coal gasification, iron oxides and calcium ferrite can be obtained. These substances can be used to prepare metallurgical dephosphorizing agents, which help remove phosphorus during the steelmaking process. This method not only purifies the flue gas but also recovers valuable metals from the dust, achieving resource recycling and reducing production costs.
[0039] Furthermore, in some embodiments, in step S1, the calcium-based materials include, but are not limited to, limestone, lime, dolomite, and hydrated lime; the organic materials include, but are not limited to, coke, coal, graphite, biochar, and plastics.
[0040] In the technical solutions of this application embodiment, calcium-based materials include, but are not limited to, limestone (calcium carbonate), lime (calcium oxide), dolomite (a composite mineral of calcium carbonate and magnesium carbonate), and hydrated lime (calcium hydroxide). Calcium-based materials exhibit high chemical activity at high temperatures, enabling them to react with sulfides and carbon dioxide produced during coal gasification, thereby achieving desulfurization and promoting the conversion of CO2 to CO. Organic materials include carbon-containing materials such as coke, coal, graphite, biochar, and plastics, which have high carbon content and are the main source of syngas in the coal gasification process. When calcium-based materials are combined with organic materials, an environment favorable to the gasification reaction is formed at high temperatures. Calcium-based materials can act as catalysts or promoters, improving gasification efficiency.
[0041] Furthermore, in some embodiments, the mass ratio of calcium-based material to organic material is (10-30%):(70-90%).
[0042] In the technical solutions of this application embodiment, an appropriate amount of calcium-based material can promote the gasification reaction, but excessive calcium-based material may occupy the space of organic material, reduce the surface area for carbon gasification reaction, and thus reduce gasification efficiency. Therefore, selecting a calcium-based material ratio of 10% to 30% can ensure sufficient catalytic effect without excessively affecting carbon gasification. Specifically, the mass ratio of calcium-based material to organic material can be any value within the range of 10%:90%, 15%:85%, 20%:80%, 30%:70%, or (10-30%):(70-90%).
[0043] Furthermore, in some embodiments, the particle size of the calcium-based material is less than 0.074 mm, and the particle size of the organic material is 0.074–0.150 mm.
[0044] In the technical solution of this application embodiment, the calcium-based material has a particle size of less than 0.074 mm, which helps to more uniformly load the organic material, thereby more effectively promoting the gasification reaction and desulfurization process. The fine particle size provides a larger specific surface area, which helps to improve the reaction rate and efficiency of the calcium-based material during the gasification process. The fine-grained calcium-based material also helps to improve its activity at high temperatures, thereby more effectively capturing and fixing the sulfur compounds generated during gasification. The organic material has a particle size of 0.074–0.150 mm, which provides sufficient reaction surface area without being too fine, thus avoiding increased airflow resistance or gasifier wear. Appropriately fine organic material helps to achieve better gasification results, ensuring both a sufficient reaction rate and stable operation of the gasifier.
[0045] Furthermore, in some embodiments, the metallurgical furnace includes, but is not limited to, metallurgical shaft furnaces, blast furnaces, converters, electric furnaces, and refining furnaces.
[0046] In the technical solution of this application embodiment, the method can adapt to the operating conditions of different metallurgical furnaces, work effectively in different metallurgical processes, and efficiently remove sulfur components from coal gas to reduce environmental pollution and equipment corrosion.
[0047] Furthermore, in some embodiments, in step S2, the coal gasification process includes the conversion of organic materials and CO2 into CO, the solidification of sulfur-containing components, and the calcification conversion of iron-containing metallurgical dust.
[0048] In the technical solution of this application embodiment, organic materials react with CO2 at high temperatures to generate CO, thereby improving the calorific value and usability of the coal gas. During the coal gasification process, calcium-based materials can react with sulfur-containing components to form solid sulfides, thereby removing sulfur from the coal gas and reducing environmental pollution. Iron-containing dust generated during the coal gasification process can react with calcium-based materials to be converted into compounds such as calcium ferrite, which can be used to prepare metallurgical dephosphorizing agents.
[0049] Furthermore, in some embodiments, the sulfur-containing components include, but are not limited to, SO2, H2S, and COS.
[0050] In the technical solutions of this application embodiment, the sulfur-containing components include a variety of sulfides. The sulfur-containing components are derived from the cracking of organic materials and the volatilization of sulfur-containing components in minerals during the smelting process. The main components include, but are not limited to, SO2, H2S, and COS.
[0051] Furthermore, in some embodiments, the calcium-based material solidifies the sulfur-containing components in the flue gas in the form of CaS before entering the dust removal system.
[0052] In the technical solution of this application embodiment, the calcium-based material can react with sulfides in the flue gas during the coal gasification process to generate solid calcium sulfide (CaS), thereby achieving the solidification of sulfur.
[0053] Furthermore, in some embodiments, the iron-containing metallurgical dust includes, but is not limited to, magnetite, ferric oxide, ferrous oxide, and iron.
[0054] In the technical solution of this application embodiment, the iron-containing substances in the metallurgical furnace flue gas are formed by splashing of molten iron / steel and slag during the smelting process, and the main components include, but are not limited to, iron(II,III) oxide, iron oxide, ferrous oxide and iron.
[0055] Furthermore, in some embodiments, the calcification conversion products of iron-containing metallurgical dust include, but are not limited to, calcium ferrite, magnesium-containing calcium ferrite, silicon-containing calcium ferrite, and complex calcium ferrite.
[0056] In the technical solution of this application embodiment, the calcification conversion of calcium-based materials with iron-containing metallurgical dust not only helps to remove harmful components in the dust, but also improves the performance of metallurgical slag and increases the metal recovery rate. The calcification conversion products can all be used in the production of subsequent dephosphorizing agents.
[0057] The following are some specific embodiments. It should be noted that the embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting this application. Where specific techniques or conditions are not specified in the embodiments, they shall be performed in accordance with the techniques or conditions described in the literature in this field or according to the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be obtained commercially.
[0058] Example 1
[0059] This embodiment provides a method for simultaneously preparing a metallurgical dephosphorizing agent and improving the gasification effect of coal gasification in a calcium-based enhanced metallurgical furnace gasification flue, as well as for flue gas desulfurization. The metallurgical furnace used is a 100t converter, and the calcium-based material is calcium oxide. The calcium oxide is pulverized to a particle size below 200 mesh, the coal powder particle size is between 100 and 200 mesh, and the moisture content of the material is less than 1% by weight. Figure 1 As shown, the specific steps include:
[0060] S1. During converter gas recovery, 10% by mass of pulverized calcium oxide powder and 90% by mass of coal powder are mixed to ensure that the calcium oxide powder is evenly loaded onto the coal powder.
[0061] S2. Using a jet injection system, pulverized coal loaded with calcium oxide powder is injected into the vaporization cooling flue. The carrier gas used for injection is nitrogen, with a nitrogen flow rate of 0.1 m³ / s. 3 / 2kg of calcium oxide powder and coal powder mixture, the injection rate of calcium oxide powder and coal powder mixture is 20kg / t steel;
[0062] S3. The metallurgical dust after treatment is collected by a dust removal system, and then purified by magnetic separation to obtain iron oxides and calcium ferrite;
[0063] S4. The obtained iron oxide and calcium ferrite are used in the preparation of metallurgical dephosphorizing agents.
[0064] Comparative Example 1
[0065] Comparative Example 1 provides a method for simultaneously preparing metallurgical dephosphorizing agent by improving the gasification effect of coal gasification in the gasification flue of a calcium-based enhanced metallurgical furnace and desulfurizing the flue gas. Compared with Example 1, the only difference is that calcium oxide powder was not added. Other experimental parameters and conditions are basically the same as those in Example 1, and will not be repeated here.
[0066] Ten loaded experiments and ten unloaded blank control experiments were conducted using the method described above. The collected metallurgical dust was analyzed, and the average values of the results from the ten loaded experiments and ten unloaded experiments were calculated for each gas. The results showed that in the experiments with calcium-based material loading, CO increased by 10%, CO2 decreased by 13%, H2S decreased by 82%, SO2 decreased by 77%, and COS decreased by 90%.
[0067] Example 2
[0068] This embodiment provides a method for simultaneously preparing a metallurgical dephosphorizing agent and improving the gasification effect of coal gasification in a calcium-based enhanced metallurgical furnace gasification flue, as well as for flue gas desulfurization. The metallurgical furnace used in the smelting is a 50t electric furnace, and the calcium-based material used is calcium carbonate. The calcium carbonate is pulverized to a particle size of less than 200 mesh, the coke powder particle size is between 100 and 200 mesh, and the moisture content of the material is less than 1% by weight. The specific steps include:
[0069] S1. During the recovery of electric furnace gas, 20% by mass of pulverized calcium carbonate powder and 80% by mass of coke powder are mixed to ensure that the calcium carbonate powder is evenly loaded onto the coke powder.
[0070] S2. Using a spray system, coke powder loaded with calcium carbonate powder is sprayed into the vaporization cooling flue. The carrier gas used for spraying is nitrogen, with a flow rate of 0.15 m³ / h. 3 / 2kg of calcium carbonate powder and coke powder mixture, the injection rate of calcium carbonate powder and coke powder mixture is 20kg / t steel;
[0071] S3. The metallurgical dust after treatment is collected by a dust removal system, and then purified by magnetic separation to obtain iron oxides and calcium ferrite;
[0072] S4. The obtained iron oxide and calcium ferrite are used in the preparation of metallurgical dephosphorizing agents.
[0073] Comparative Example 2
[0074] Comparative Example 2 provides a method for simultaneously preparing metallurgical dephosphorizing agent by improving the gasification effect of coal gasification in the gasification flue of a calcium-based enhanced metallurgical furnace and desulfurizing the flue gas. Compared with Example 2, the only difference is that calcium carbonate powder was not added. Other experimental parameters and conditions are basically the same as those in Example 2, and will not be repeated here.
[0075] Ten loaded experiments and ten unloaded blank control experiments were conducted using the method described above. The collected metallurgical dust was analyzed, and the average values of the results from the ten loaded experiments and ten unloaded experiments were calculated for each gas. The results showed that in the experiments with calcium-based material loading, CO increased by 7%, CO2 decreased by 9%, H₂S decreased by 85%, SO₂ decreased by 78%, and COS decreased by 93%.
[0076] Example 3
[0077] This embodiment provides a method for simultaneously preparing a metallurgical dephosphorizing agent by improving the gasification effect of coal gasification in a calcium-based enhanced metallurgical furnace gasification flue and desulfurizing the flue gas. The metallurgical furnace used in the smelting is a 2000m³ furnace. 3 The blast furnace uses calcium hydroxide as its calcium-based material. The calcium hydroxide is pulverized to a particle size below 200 mesh, the coal powder particle size is between 100 and 200 mesh, and the moisture content of the material is less than 1% by weight. The specific steps include:
[0078] S1. During blast furnace gas recovery, 15% by mass of pulverized calcium hydroxide powder and 85% by mass of coal powder are mixed to ensure that the calcium hydroxide powder is evenly loaded onto the coal powder.
[0079] S2. Using a jet injection system, the pulverized coal loaded with calcium hydroxide is injected into the vaporization cooling flue. The carrier gas used for injection is nitrogen, with a flow rate of 0.1 m³ / s. 3 / 2kg of calcium hydroxide powder and coal powder mixture, the injection rate of the calcium hydroxide powder and coal powder mixture is 0.004kg / m 3 iron;
[0080] S3. The metallurgical dust after treatment is collected by a dust removal system, and then purified by magnetic separation to obtain iron oxides and calcium ferrite;
[0081] S4. The obtained iron oxide and calcium ferrite are used in the preparation of metallurgical dephosphorizing agents.
[0082] Comparative Example 3
[0083] Comparative Example 3 provides a method for simultaneously preparing metallurgical dephosphorizing agent by improving the gasification effect of coal gasification in the gasification flue of a calcium-based enhanced metallurgical furnace and desulfurizing the flue gas. Compared with Example 3, the only difference is that calcium hydroxide powder was not added. Other experimental parameters and conditions are basically the same as those in Example 3, and will not be repeated here.
[0084] Ten loaded experiments and ten unloaded blank control experiments were conducted using the method described above. The collected metallurgical dust was analyzed, and the average values of the results from the ten loaded experiments and ten unloaded experiments were calculated for each gas. The results showed that in the experiments with calcium-based material loading, CO increased by 9%, CO2 decreased by 14%, H₂S decreased by 81%, SO₂ decreased by 83%, and COS decreased by 93%.
[0085] Compared with the traditional converter gasification flue gasification process, the method of this application can reduce energy consumption by more than 90%. At the same time, the obtained calcium ferrite has high activity and excellent dephosphorization ability.
[0086] The optimal mass ratio of calcium-based materials is between 10% and 30%. The mixture is injected into the gasification flue of the metallurgical furnace for reaction. By enhancing the coal gasification reaction, the calcium-based materials, as shown in the examples, improve carbon monoxide quality, recover a large amount of CO as an important raw material for chemical production, possessing extremely high economic value, and significantly reduce carbon dioxide emissions, thus contributing to effective carbon emission management. The sulfide conversion rate is between 80% and 95%, demonstrating significant desulfurization. The calcium ferrite generated in the flue dust has good magnetic properties, facilitating magnetic separation, and the resulting dephosphorizing agent exhibits significant dephosphorization effects.
[0087] In summary, the method for simultaneously preparing metallurgical dephosphorizing agents and enhancing the gasification effect of the gasification duct of a metallurgical furnace with calcium-based materials, as well as for flue gas desulfurization, provided in this application, involves loading calcium-based materials onto organic materials and injecting them into the gasification duct of the metallurgical furnace using a spraying system. The calcium-based materials enhance the cracking and gasification of organic fuels, promoting the cracking of macromolecular organic matter, increasing calorific value, and driving the reaction of carbon-containing organic materials with H2O / CO2 to generate CO, thereby improving CO recovery rate, CO2 conversion rate, and gas grade, reducing carbon emissions, and improving energy utilization and economic benefits. Simultaneously, the calcium-based materials solidify the sulfur-containing flue gas (SO2, H2S, COS, etc.) released from the cracking of organic materials and ore, generating stable CaS, which enters the dust removal system with the flue gas, achieving sulfur emission control and reducing environmental pollution. Furthermore, the calcium-based materials react with iron-containing components in the flue gas to generate calcium ferrite, which, after magnetic separation and purification, is used to prepare high-value-added dephosphorizing agents, reducing production costs, improving steel quality, achieving energy conservation and environmental protection, and enhancing economic benefits.
[0088] It should be noted that this application is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments with the same structure and effect as the technical concept within the scope of this application are included in the technical scope of this application. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of this application, are also included in the scope of this application.
Claims
1. A method for simultaneously preparing a metallurgical dephosphorizing agent by improving the gasification effect of coal gasification in a calcium-based enhanced metallurgical furnace gasification flue and desulfurizing the flue gas, characterized in that... Includes the following steps: S1. Loading calcium-based material of a predetermined particle size with organic material for coal gasification, so that the calcium-based material is uniformly loaded onto the organic material; S2. Using an injection device, the organic material loaded with calcium-based material in step S1 is injected into the high-temperature gasification flue of the metallurgical furnace for coal gasification treatment. S3. Collect the metallurgical dust processed in step S2 through a dust removal system, and then separate and purify it by magnetic separation to obtain iron oxide and calcium ferrite; S4. The iron oxide and calcium ferrite obtained in step S3 are used in the preparation of a metallurgical dephosphorizing agent.
2. The method for simultaneously preparing metallurgical dephosphorizing agent and improving the gasification effect of coal gasification in the gasification flue of a calcium-based enhanced metallurgical furnace and the desulfurization of flue gas, as described in claim 1, is characterized in that... In step S1, the calcium-based material includes, but is not limited to, limestone, lime, dolomite, and hydrated lime; the organic material includes, but is not limited to, coke, coal, graphite, biochar, and plastics.
3. The method for simultaneously preparing metallurgical dephosphorizing agent and improving the gasification effect of coal gasification in the gasification flue of a calcium-based enhanced metallurgical furnace and for flue gas desulfurization, as described in claim 2, is characterized in that... The mass ratio of the calcium-based material to the organic material is (10-30%):(70-90%).
4. The method for simultaneously preparing metallurgical dephosphorizing agent and improving the gasification effect of coal gasification in the gasification flue of a calcium-based enhanced metallurgical furnace and for flue gas desulfurization according to claim 3, characterized in that, The calcium-based material has a particle size of less than 0.074 mm, and the organic material has a particle size of 0.074 to 0.150 mm.
5. The method for simultaneously preparing metallurgical dephosphorizing agent and improving the gasification effect of calcium-based enhanced metallurgical furnace gasification flue gas as described in claim 1, characterized in that, The metallurgical furnaces include, but are not limited to, metallurgical shaft furnaces, blast furnaces, converters, electric furnaces, and refining furnaces.
6. The method for simultaneously preparing metallurgical dephosphorizing agent and improving the gasification effect of calcium-based enhanced metallurgical furnace gasification flue gas as described in claim 1, characterized in that, In step S2, the coal gasification process includes the conversion of organic materials and CO2 into CO, the solidification of sulfur-containing components, and the calcification conversion of iron-containing metallurgical dust.
7. The method for simultaneously preparing metallurgical dephosphorizing agent and improving the gasification effect of coal gasification in the gasification flue of a calcium-based enhanced metallurgical furnace and for flue gas desulfurization according to claim 6, characterized in that, The sulfur-containing components include, but are not limited to, SO2, H2S, and COS.
8. The method for simultaneously preparing metallurgical dephosphorizing agent and improving the gasification effect of coal gasification in the gasification flue of a calcium-based enhanced metallurgical furnace according to claim 7, characterized in that, The calcium-based material solidifies the sulfur-containing components in the form of CaS and then enters the dust removal system.
9. The method for simultaneously preparing metallurgical dephosphorizing agent and improving the gasification effect of coal gasification in the gasification flue of a calcium-based enhanced metallurgical furnace according to claim 6, characterized in that, The iron-containing metallurgical fumes include, but are not limited to, iron(II,III) oxide, iron oxide, ferrous oxide, and iron.
10. The method for simultaneously preparing metallurgical dephosphorizing agent for gasification effect and flue gas desulfurization in calcium-based enhanced metallurgical furnace gasification flue gasification duct according to claim 6, characterized in that, The calcification conversion products of the iron-containing metallurgical dust include, but are not limited to, calcium ferrite, magnesium-containing calcium ferrite, silicon-containing calcium ferrite, and complex calcium ferrite.