Hydrogen-rich, high-oxygen, high-air temperature ironmaking fluidized bed smelting reduction furnace

Abstract

The invention discloses a hydrogen-rich, high-oxygen, high-air temperature ironmaking fluidized bed smelting reduction furnace, and relates to a hydrogen-rich, high-oxygen, high-air temperature ironmaking fluidized bed smelting reduction furnace. The furnace body is an upper expansion furnace type, including a furnace, a furnace belly and a furnace body, the furnace wall is provided with an iron mouth, a furnace coal powder spray gun and a first tuyere, the furnace wall on the upper side of the first tuyere is connected to the lower side of the furnace belly, the upper side of the furnace belly is connected to the furnace body, and the furnace body wall is provided with a block coal sealing charging port, a second tuyere and an organic spray gun; a hydrogen-rich or even pure hydrogen reducing agent is added, and after the various devices located directly above complete pre-reduction, the ore powder has been bonded into ore powder agglomerates of about 3 mm, which are directly discharged into the smelting reduction furnace, and are continuously heated, reduced, bonded and grown in the subsequent falling process until they are completely melted, avoiding the trouble of the soft melting zone of the blast furnace, reducing the FeO content in the slag and its erosion, saving the total heat consumption of the molten pool, and improving the slag iron temperature.

Description

Technical Field

[0001] The present invention relates to the technical field of smelting reduction furnaces, and in particular to a hydrogen-rich, high-oxygen, high-air-temperature ironmaking fluidized bed smelting reduction furnace. Background Art

[0002] Smelting reduction and direct reduction methods are often used in the powder ore ironmaking process. At present, a difficult problem in the iron ore fluidized bed smelting reduction process is how to economically provide the smelting reduction furnace with high temperature, high melting rate and high reduction degree iron ore powder.

[0003] Guo Hanjie and Li Lin of the University of Science and Technology Beijing published an article titled "The Future of Non-coking Coal Ironmaking Processes and Equipment", analyzing Finex, HIsarna, and HIsmelt, and pointed out that Finex is the only process that has achieved large-scale production in a relatively stable manner. Its advantage is that the coal gas produced by the final reduction furnace enters the fluidized bed after reforming to remove CO2, which improves the pre-reduction degree of the fluidized bed. The particle size of the mineral powder used is 0-8mm, the average particle size is 0.90-3.64mm, and -0.125mm accounts for 4.9-12.68%. The use of such coarse-grained mineral powder has played a significant role in reducing the adhesion and loss of fluid during the reduction process of the fluidized bed. However, it cannot be said that the adhesion and loss of fluid have been completely solved. Adhesion and loss of fluid still pose a considerable threat to production stability. The hot briquetting of pre-reduced iron powder in the Finex process increases the heat consumption and cost of the process; its smelting reduction furnace is basically the same as the Corex process, requiring the addition of 180-230kg / t iron of coke or briquette, and the sealing and distribution under high temperature conditions are difficult to reach the level of blast furnaces. In fact, the Corex process, Finex process and hydrogen-rich oxygen-rich blast furnace and other processes have the problem of airtightness during the pre-reduced ore soft melting process, and the soft melting zone has added a lot of trouble to these processes. They have to use coke skeletons and coke windows for ventilation, which not only increases the dependence on high-quality coke, related pollution, cost and resource risks, but also is a huge obstacle to further intensified smelting of these processes.

[0004] Regarding the research and development and large-scale production of smelting reduction furnaces, the publication numbers CN108251588A, CN112280922A, CN1926248A, and CN101473048A all announced the improvement and exploration of the SRV furnace of the HIsmelt process. By obliquely inserting the mineral powder, coal powder spray gun and top-blowing high-temperature oxygen-enriched spray gun into the slag layer, the liquid slag iron spring, splash and slag layer in the center of the molten pool were effectively heated with a large secondary combustion rate. Under quite difficult production conditions (rotary kiln mineral powder pre-reduction degree of 15-23%, preheating temperature of about 400°C), the ultra-high reduction rate of FeO in the liquid slag in the SRV furnace and the huge heating capacity of secondary combustion were verified, and the high temperature state of the molten pool was continuously maintained, realizing relatively stable continuous industrial-scale production. However, such a huge amount of FeO reduction, heat demand and physical heat of high-temperature exhaust gas in the SRV furnace also limit the further reduction of energy consumption and production costs of the current HIsmelt process. Pneumatic conveying of pre-reduced ore powder also increases heat consumption and costs.

[0005] At present, the HIsarna process is a more valuable improvement to the HIsmelt process. According to the article "Breakthrough Ironmaking Technology in Ultra-Low Carbon Steelmaking Project", a cyclone smelting reduction furnace is set on the arch of the SRV furnace, and room temperature ore powder, solvent and oxygen are sent into the cyclone section here. Almost all the coal gas of the SRV furnace is burned here to produce a high temperature of about 1571.3℃, quickly completing physical water evaporation, crystal water and carbonate decomposition, polymerization melting, and heating to about 1450℃. Through thermal decomposition and reduction, the pre-reduction degree of about 20% is achieved. This is very large. One advantage is that it can achieve a very high production efficiency; the central oxygen-enriched hot air lance is replaced by several pure oxygen lances inserted obliquely from the arch to achieve a secondary combustion rate of about 42.9%, maintaining the molten pool working capacity of the Molong HIsmelt process, and compared with the SRV furnace molten pool of the HIsmelt process, it greatly increases the total heat income and saves the amount of reduction. It is expected to achieve better production indicators than the Molong HIsmelt process, and even approach or be lower than the energy consumption of the blast furnace itself, although the pre-reduction degree still needs to be improved, and continuing to improve the pre-reduction degree of the ore powder will also encounter great difficulties.

[0006] CN102690919A discloses a flash metallurgical method for iron, in which the physical heat carried by the dry iron ore powder, fuel and oxygen in the reaction tower is too little, and the flue gas passing through the high-temperature molten pool is recovered through a reburning waste heat boiler, and its efficiency is unsatisfactory, which will increase the total fuel consumption of the entire process.

[0007] For smelting reduction furnaces or iron bath furnaces of different processes, there are problems to varying degrees in how to economically increase the preheating temperature and reduction degree of ore powder, especially in coordination with the pre-reduction device, how to reduce the resistance of materials to airflow during the soft melting process, and even in the preparation and supply of reducing gas, transportation of pre-reduction raw materials, life and reliability of smelting reduction furnace bodies and equipment, etc., which increase additional heat consumption and costs. Summary of the invention

[0008] In order to solve the above technical problems, the present invention provides a hydrogen-rich, high-oxygen, high-air-temperature ironmaking fluidized bed smelting reduction furnace, which can avoid heat dissipation losses as much as possible, improve production efficiency, energy utilization, and operational reliability and stability.

[0009] To achieve this technical purpose, the present invention adopts the following scheme: a hydrogen-rich, high-oxygen, high-wind temperature ironmaking fluidized bed smelting reduction furnace, the fluidized bed smelting reduction furnace is an upper expansion furnace type, including a furnace bottom, a furnace cylinder, a furnace belly and a furnace body, wherein the furnace bottom is connected to the lower side of the furnace cylinder wall, and the furnace cylinder wall is provided with an iron mouth, a furnace cylinder pulverized coal spray gun and a first tuyere; the furnace cylinder wall on the upper side of the first tuyere is connected to the lower side of the furnace belly, and the upper side of the furnace belly is connected to the furnace body, and the furnace body wall is provided with a sealed lump coal feeding port, a second tuyere and an organic spray gun.

[0010] Compared with the prior art, the beneficial effects of the present invention are as follows: the ore powder agglomerates that have been preheated, pre-reduced, and bonded into more than 3 mm are directly discharged into the smelting reduction furnace, and are continuously heated, reduced, bonded and grown in the subsequent falling process until they are completely melted, thereby avoiding the problem of the soft melting zone of the blast furnace, reducing the FeO content in the slag and its corrosive effect, saving the total heat consumption of the molten pool, and increasing the slag iron temperature.

[0011] The preferred embodiment of the present invention is:

[0012] The furnace body is also equipped with an intelligent furnace wall thickness control device.

[0013] Both the furnace belly and the furnace body are generally expanded structures.

[0014] The angle between the inner curved surface generatrix of the furnace belly wall and the horizontal plane is in the range of 0° to 87°, preferably in the range of 0° to 45°, and the angle between the inner curved surface generatrix of the furnace body wall and the horizontal plane is in the range of 25° to 90°, preferably in the range of 70° to 87°. The inner profile of the furnace belly and the furnace body is allowed to be composed of more than one cone segment with different generatrix angles, and even the generatrix of the inner profile is allowed to be a curve.

[0015] The furnace cavity below the taphole is the dead iron layer, the furnace cavity at the same height as the taphole is the molten iron layer, the furnace cavity between the furnace coal powder spray gun and the taphole is the slag layer, the furnace coal powder spray gun forms a slag iron spring area in the middle of the furnace cavity, and the first tuyere forms a primary combustion zone in the furnace cavity, which is located on the upper surface of the slag layer and the slag iron spring area. The average temperature of the slag layer is as high as 1550℃~1650℃, and coarse coal powder (0~6mm) is sprayed here, and its jet can reach the molten iron layer to ensure the carburization of the molten iron and the reduction of FeO in the slag. The content of FeO in the slag is about 1%, and the average temperature of the molten iron layer is stable at 1430~1550℃. The furnace bottom is cooled (similar to the bottom of a blast furnace) to stabilize the surface temperature of the carbon bricks at 1050℃ to prevent the erosion of the carbon bricks.

[0016] The angle between the axis of the furnace coal powder spray gun and the horizontal plane is 10°~60°, preferably 15°~45°. The 0~6mm coarse coal powder sprayed in provides a reducing agent for the molten pool and supplementary carburization of the molten iron. The carrier gas is the cold circulating coal gas of this process, and nitrogen or superheated steam is only used as a security purge gas, which not only ensures safety but also reduces the introduction of nitrogen. Nitrogen or superheated steam can also be used as a carrier gas. The jet reaches the molten iron layer directly, thereby stirring up a slag and iron spring area in the center of the molten pool, strengthening the mass transfer, heat transfer and various reaction rates of the furnace; a small amount of mineral powder or dust ash can also be added to the coal powder to adjust the oxygen potential of the molten pool, strengthen dephosphorization or inhibit over-reduction of TiO2, and avoid the slag and iron from becoming sticky; the coal powder can also be added with or even completely replaced by organic matter such as hydrogen, coke oven gas, natural gas, biomass or organic waste, etc., to increase hydrogen-rich or even pure hydrogen reducing agents. The hydrogen-rich refers to the hydrogen content of the coal gas generated after the volatile matter in the coke oven gas, natural gas, biomass or organic waste and coal powder enters the device, which is greatly improved compared with blast furnace gas.

[0017] The furnace cavity above the slag layer is a coke particle spouting fluidized bed zone. After the lump coal enters the furnace from the upper edge of the furnace belly, it is heated and distilled in the process of moving to the furnace, that is, it is transformed into coke particles, where it undergoes a violent primary combustion with the high-temperature oxygen-enriched ≥30% hot air of about 1200℃ or pure oxygen at room temperature from the first tuyere.

[0018] The angle between the axis of the first tuyere and the horizontal plane is 0°~45°, preferably 0°~30°. The focal point temperature of the primary combustion zone exceeds about 2100°C, and is close to the slag spring area and the slag layer surface, providing sufficient high-temperature heat for the molten pool. The liquid slag dripping from above into the coke particle spouting fluidized bed belt and the high-viscosity creeping slag slowly flowing down the furnace wall are quickly heated and reduced here, and completely melted, with an average reduction degree of about 90%, which increases the high-temperature heat income of the molten pool, saves the total amount of direct reduction of the molten pool, and improves the thermal stability of the molten pool. The coal gas produced by various reactions in the molten pool, the carrier gas of the pulverized coal spray gun in the furnace and the pulverized coal cracking materials, as well as the combustion products of the first tuyere, provide sufficient fluidizing and spouting media for the coke particle spouted fluidized bed, ensuring the active state of the six-phase high-temperature spouted fluidized bed (gas phase, liquid iron phase, liquid slag phase, foamy slag phase, solid coke particles and trace solid ore blocks), improving the air permeability and liquid permeability, and stabilizing the average bed temperature of the main bed layer of the coke particle spouted fluidized bed at 1650-1800℃. Its overall properties are better than those of the combustion zone and dripping zone of the blast furnace.

[0019] The angle between the axis of the sealed lump coal charging port and the horizontal plane is 0°~43°; the edge of the furnace belly cavity obliquely below the sealed lump coal charging port forms a local coal lump moving bed area. In order to improve the thermal stability of the high temperature zone of this molten reduction furnace, 3-60mm lump coal is added from the sealed lump coal charging port. The lump coal continuously entering the furnace forms a local lump coal moving bed pile on the furnace belly wall with the same number as the sealed lump coal charging port. In the process of slowly moving downward, it absorbs the radiation heat of the secondary combustion zone and the heat of the furnace cylinder gas, heats up the dry distillation and coking, and after the coke particles are formed, they enter the coke particle spouting fluidized bed zone, and the volatile matter in the coal enters the furnace body gas, which improves the hydrogen enrichment effect of the gas.

[0020] The axis of the second tuyere includes an angle of 0°~45° with the horizontal plane, the second tuyere intersects with the inner profile of the furnace wall to form an intersection, the axis of the second tuyere forms a projection line in the cross section of the furnace wall where the intersection is located, and the angle between the projection line and the radius of the cross section of the furnace wall at the intersection is 0~50°, so as to form a spiral secondary combustion zone in the lower part of the furnace body.

[0021] The angle between the axis of the organic spray gun and the horizontal plane is between 0° and 45°. The organic spray gun intersects with the inner shape of the furnace wall to form an intersection. The axis of the organic spray gun forms a projection line on the cross section of the furnace wall where the intersection is located. The angle between the projection line and the radius of the cross section of the furnace wall at the intersection is between 0° and 50°, so as to form a spiral gas reforming zone at the lower part of the furnace body. The organic spray gun is tangent to a virtual circle with a diameter of 10% to 50% of the inner diameter of the furnace shape at that location in a clockwise direction, forming a clockwise spiral airflow field (or counterclockwise), where hydrogen, coke oven gas, natural gas, 0 to 6 mm biomass or coal powder or organic waste organic matter is sprayed to increase hydrogen-rich or even pure hydrogen reducing agent. In order to form a spiral coal gas reforming zone at the lower part of the furnace body, the coal volatiles and carbon particles or other organic matter are used to complete the reforming of the coal gas, providing high-temperature coal gas with good high reduction potential for the subsequent fluidized bed reduction, avoiding the reduction of the calorific value of the coal gas and the heat loss. At the same time, a considerable part of the high-reduction ore agglomerates (about 4mm) passing through this area will complete melting and further bond and aggregate, and the average reduction degree will be further increased to about 75%. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic longitudinal section of a hydrogen-rich, high-oxygen, high-air temperature ironmaking fluidized bed smelting reduction furnace provided in an embodiment of the present invention;

[0023] The markings in the figure are: 1. Foundation; 11. Furnace bottom; 12. Furnace hearth; 13. Furnace belly; 14. Furnace body; 2. Iron mouth; 3. Furnace hearth coal powder spray gun; 4. First air inlet; 5. Lump coal sealed feeding port; 6. Second air inlet; 7. Organic matter spray gun; 8. Intelligent furnace wall thickness control device; 9. Cold circulation gas distribution pipe. DETAILED DESCRIPTION

[0024] In order to fully understand the purpose, features and effects of the present invention, the present invention is described in detail through the following specific implementation methods, but the present invention is not limited thereto.

[0025] like Figure 1 As shown, the present invention provides a hydrogen-rich, high-oxygen, high-air temperature ironmaking fluidized bed smelting reduction furnace, which is an upper expansion furnace type, including a foundation 1, a furnace bottom 11, a furnace 12, a furnace belly 13 and a furnace body 14, etc. The wall of the furnace 12 is provided with an iron mouth 2, a furnace pulverized coal spray gun 3 and a first tuyere 4, the wall of the furnace 12 on the upper side of the first tuyere 4 is connected to the lower side of the furnace belly 13, and the upper side of the furnace belly 13 is connected to the furnace body 14, and the wall of the furnace body 14 is provided with a sealed lump coal feeding port 5, a second tuyere 6, an organic spray gun 7 and an intelligent furnace wall thickness control device 8. Various pre-reduction devices can be arranged above the fluidized bed smelting reduction furnace.

[0026] The angle between the inner curved surface generatrix of the wall of the furnace belly 13 and the horizontal plane is in the range of 0° to 87°, preferably in the range of 0° to 45°; the angle between the inner curved surface generatrix of the wall of the furnace body 14 and the horizontal plane is in the range of 25° to 90°, preferably in the range of 70° to 87°. The inner profiles of the furnace belly 13 and the furnace body 14 are allowed to be composed of more than one conical segment with different generatrix angles, and even the generatrix of the inner profile is allowed to be a curve.

[0027] The wall of the furnace 12 adopts a copper composite cooling wall, the brickwork of the wall of the furnace 12 above the iron mouth 2 adopts high-density bricks containing zirconium or chromium, and other parts adopt cooling equipment and brickwork corresponding to the blast furnace. High-pressure closed-circulation soft water is used as the cooling medium. The furnace type and organic spray gun, iron mouth, intelligent furnace wall thickness control device, sealed feeding port, tuyere and other structures of the reduction furnace of the present invention are matched to form a more stable slag skin protective layer together with the furnace wall, which greatly improves the ability to resist molten iron scouring, avoids the occurrence of supercooled film boiling state, and prolongs the service life.

[0028] More optimally, the furnace wall of the fluidized bed smelting reduction furnace is provided with 1 to 4 iron openings 2 from bottom to top, one to three rows of hearth coal powder spray guns 3, one to more sets of hearth coal powder spray guns 3 in each row, two to more sets of first air inlets 4, two to more sets of lump coal sealed feeding ports 5, one to three rows of second air inlets 6, two to more sets of second air inlets 6 in each row, two to three rows of organic spray guns 7, two to more sets of organic spray guns 7 in each row, three to more rows of intelligent furnace wall thickness control devices 8, six to more sets of intelligent furnace wall thickness control devices 8 and other auxiliary equipment in each row, the hearth coal powder spray guns 3 and the organic spray guns 7 are patent technologies that the applicant has authorized (publication number CN114018058B), and the intelligent furnace wall thickness control device 8 is patent technology that the applicant has authorized (publication number CN114812211B).

[0029] The fixing and sealing structures of the above-mentioned tuyere, spray gun and charging port devices are similar to the structural concept of the three sets of blast furnace tuyere or other fixing and sealing structures to facilitate installation and disassembly; the discharge of slag and iron also adopts mature devices and technologies such as the blast furnace iron mouth device, opening machine, mud gun, slag and iron separator, which will not be repeated in this article.

[0030] The furnace of the hydrogen-rich, high-oxygen, high-air-temperature ironmaking fluidized bed smelting reduction furnace formed by the above structure is divided into a dead iron layer S, a molten iron layer T, a slag layer U, a slag-iron spring area V, a coke particle spouting fluidized bed zone X, a local lump coal moving bed zone Y, a secondary combustion zone Z, a coal gas reforming zone J, a high-temperature reduction zone K, and a temperature adjustment zone N from bottom to top.

[0031] The furnace cylinder 12 cavity below the tap hole 2 is a dead iron layer S, the furnace cylinder 12 cavity at the same height as the tap hole 2 is a molten iron layer T, the furnace cylinder pulverized coal spray gun 3 and the tap hole 2 is a slag layer U, the furnace cylinder pulverized coal spray gun 3 forms a slag iron spring area V in the center of the furnace cylinder 12 cavity, and the first tuyere 4 forms a primary combustion zone W in the furnace cylinder 12 cavity, and the primary combustion zone W is located on the upper surface of the slag layer U and the slag iron spring area V.

[0032] The angle between the axis of the furnace coal powder spray gun 3 arranged on the slag layer U and the horizontal plane is 10°~60°, preferably 15°~45°. The 0-6 mm coarse-grained coal powder thus injected uses the cold circulating coal gas of this process as the carrier gas, which not only ensures safety but also reduces the introduction of nitrogen. Its jet reaches the molten iron layer T directly, thereby stirring up the slag and iron spring area V in the center of the molten pool, strengthening the mass transfer and heat transfer of the furnace 12 and its various reaction rates. A small amount of mineral powder or dust removal ash can also be added to the coal powder to adjust the oxygen potential of the molten pool, strengthen dephosphorization or inhibit over-reduction of TiO2, and avoid slag iron from becoming sticky; the coal powder can also be added or even completely replaced by hydrogen, coke oven gas, natural gas, biomass or organic waste and other organic matter to increase hydrogen-rich or even pure hydrogen reducing agents.

[0033] The average temperature of the slag layer U is as high as 1550℃~1650℃. Coarse coal powder (0~6mm) and organic matter such as hydrogen are sprayed here. The jet can reach the molten iron layer T to ensure carburization of the molten iron and reduction of FeO in the slag. The content of FeO in the slag is about 1%. The average temperature of the molten iron layer T is stable at 1430~1550℃. The furnace bottom 11 is cooled to stabilize the surface temperature of the carbon brick at 1050℃ to prevent the erosion of the carbon brick. Its working state is closer to that of the blast furnace hearth and the hearth of Corex and Finex. Compared with HIsarna and HIsmelt, the total reduction amount of FeO in its slag (about 4%) and heat demand are saved a lot, and the loss of valuable elements such as iron with the slag is also avoided. If high-phosphate ore or vanadium-titanium ore is processed, part of the dust removal ash or mineral powder of the furnace top of this process can be sprayed here to increase the oxygen potential of the slag iron layer and avoid over-reduction.

[0034] The cavity of the furnace 12 above the slag layer U is a coke particle spouting fluidized bed zone X. The lump coal enters the coke particle spouting fluidized bed zone X of the furnace 12 (synchronous dry distillation) and undergoes intense primary combustion with the 1200℃ high temperature oxygen-enriched ≥30% hot air or room temperature pure oxygen from the first tuyere 4.

[0035] The angle between the axis of the first tuyere 4 and the horizontal plane is 0°~45°, preferably 0°~30°. The focal point temperature of the primary combustion zone W is about 2100°C, and is close to the slag spring area V and the surface of the slag layer U, providing sufficient high-temperature heat for the molten pool. The liquid slag dripping from the top into the coke particle spouting fluidized bed zone X and the high-viscosity creeping slag slowly flowing down the furnace wall are quickly heated and reduced here, and completely melted, with an average reduction degree of about 90%, which increases the high-temperature heat income of the molten pool, saves the total amount of direct reduction of the molten pool, and improves the thermal stability of the molten pool. The average temperature of the slag layer U is stable at 1550~1650°C, and the average temperature of the molten iron layer T is stable at 1430~1550°C. The furnace bottom is cooled to stabilize the surface temperature of the carbon bricks at 1050°C to prevent erosion of the carbon bricks. The coal gas produced by various reactions in the molten pool, the carrier gas of the coal powder spray gun in the furnace, the organic matter or coal powder cracking substances, and the combustion products of the first tuyere provide sufficient fluidizing and spouting media for the coke particle spouted fluidized bed belt X, ensuring the active state of the six-phase high-temperature spouted fluidized bed (gas phase, liquid iron phase, liquid slag phase, foamy slag phase, solid coke particles and trace solid ore blocks), improving the air permeability and liquid permeability, and stabilizing the main bed temperature of the coke particle spouted fluidized bed belt at 1650-1800°C.

[0036] The angle between the axis of the sealed lump coal charging port 5 and the horizontal plane is 0°~43°; the edge of the furnace belly 13 cavity obliquely below the sealed lump coal charging port 5 forms a local lump coal moving bed area Y. In order to improve the thermal stability of the high temperature zone of the molten reduction furnace, 3-60 mm lump coal is added from the sealed lump coal charging port 5. The lump coal continuously fed into the furnace forms a local lump coal moving bed area Y equal to the number of the sealed lump coal charging port 5 on the wall of the furnace belly 13. In the process of slowly moving downward, it absorbs the radiation heat of the secondary combustion zone and the heat of the furnace hearth gas, heats up and drys and cokes to become coke particles, enters the coke particle spout fluidized bed zone X, and undergoes violent primary combustion with the 1200℃ oxygen-rich (oxygen content ≥30%) high wind temperature wind or room temperature pure oxygen from the first tuyere 4, and the volatile matter in the coal enters the furnace body coal gas, improving the hydrogen-enriched effect of the coal gas.

[0037] The axis of the second tuyere 6 includes an angle of 0°~45° with the horizontal plane. The second tuyere 6 intersects with the inner profile of the furnace wall to form an intersection. The axis of the second tuyere 6 forms a projection line on the cross section of the furnace wall at the intersection. The angle between the projection line and the radius of the cross section of the furnace wall at the intersection is 0~50°, so as to form a spiral secondary combustion zone at the lower part of the furnace body 14.

[0038] The second tuyere 6 is tangent to a virtual circle with a diameter of 10-50% of the inner diameter of the furnace at that location in a clockwise direction to form a clockwise spiral airflow field (counterclockwise is also possible), from which 1200℃ high-temperature hot air with oxygen enrichment ≥30% or pure oxygen at room temperature is sprayed, and the secondary combustion focus of the molten pool gas is as high as about 2200℃, providing a strong high-temperature heat for the molten pool. At the same time, most of the high-reduction ore agglomerates passing through this area will be melted, and further bonded and aggregated into larger droplets (about 5mm), and preheated to about 1550℃. The reduction and reoxidation of the ore in this area coexist. Due to the small oxidation area, the overall average reduction degree of the ore is slightly increased to about 80%. The high CO2 gas in the secondary combustion zone Z, after completing the preheating of the ore agglomerates, still has an average temperature of about 1800℃, and this high-temperature heat is just suitable for gas reforming.

[0039] The angle between the axis of the organic spray gun 7 and the horizontal plane is between 0° and 45°. The organic spray gun 7 intersects with the inner profile of the furnace wall to form an intersection. The axis of the organic spray gun 7 forms a projection line in the cross section of the furnace wall where the intersection is located. The angle between the projection line and the radius of the cross section of the furnace wall at the intersection is between 0° and 50°, so as to form a spiral gas reforming zone J at the lower part of the furnace body 14. The organic spray gun 7 is tangent to a virtual circle whose diameter is 10 to 50% of the inner diameter of the furnace at that location in a clockwise direction, forming a clockwise spiral airflow field (counterclockwise is also possible), and hydrogen, coke oven gas, natural gas, 0 to 6 mm biomass or coal powder or organic waste and other organic matter are sprayed here to increase hydrogen-rich or even pure hydrogen reducing agent, and utilize coal volatiles and carbon particles or other organic matter to complete the reforming of coal gas, providing good high-reduction potential high-temperature coal gas for subsequent fluidized bed reduction, avoiding the reduction of coal gas calorific value and heat loss, and at the same time, a considerable portion of the high-reduction ore agglomerates (about 4 mm) passing through this area will complete melting and further bond and aggregate, and the average reduction degree will also be further increased to about 75%.

[0040] In the upper middle part of the furnace body 14, the reformed coal gas enters the high-temperature reduction zone K, and the mineral powder agglomerates evenly falling from the top are continuously reduced and heated in the high-temperature reduction zone K, so that the average temperature of the mineral powder agglomerates reaches about 950°C, and the fine mineral powder continues to bond and aggregate, and the average particle size reaches about 3mm and reaches a softened state, and the average reduction degree reaches about 70%.

[0041] As the average gas temperature decreases, more than three rows of intelligent furnace wall thickness control devices are densely arranged on the wall of the furnace body 14 to control the thickness and nodules of the furnace wall.

[0042] A temperature adjustment zone N is designed above the high-temperature reduction zone K. A cold circulating gas distribution pipe 9 is set on the furnace wall at the height of the temperature adjustment zone N, and the cold circulating gas produced by this process is introduced to cool the high-temperature gas H to 800℃~900℃ and 700~850℃ twice to meet the gas temperature requirements of the pre-reduction large-speed difference stirring spouted fluidized bed arranged above. The average temperature of the ore powder aggregate M in the temperature adjustment zone N is increased by 30℃~80℃, and the average reduction degree is increased by about 3%.

[0043] In the smelting reduction furnace above the coke particle spout fluidized bed, in terms of the vertical motion velocity component, the relative velocity and direction of the mineral powder agglomerates or droplets to the furnace body is approximately equal to the difference between the terminal settling velocity and the gas flow velocity. The gas flow velocity (relative to the furnace body) is slightly lower than that of the fast fluidized bed, but higher than that of the turbulent fluidized bed, which belongs to a kind of dilute phase fluidized bed, and the gas flow is a spiral rotating flow field (all kinds of spray gun jets have a certain tangential angle, which can be either clockwise or counterclockwise spiral flow field). In this fluidized state, some small-sized mineral powder agglomerates or small droplets will be carried upward by the air flow, and some will grow by collision and adhesion; while large-sized mineral powder agglomerates or large droplets will move downward, which is an ideal countercurrent heat transfer and countercurrent reaction process, which is conducive to improving energy utilization. More importantly, the softening and melting process of the mineral powder agglomerates is completed in the dilute phase fluidized bed of the high-temperature spiral gas flow field, without increasing the gas flow resistance, and completely eliminating the negative effects of the blast furnace soft melting zone (moving bed). One of the core theoretical innovations of the present invention is to utilize the bonding phenomenon of mineral powder to promote the bonding of mineral powder into agglomerates and the growth of agglomerates, and to assist with an appropriate ratio of coarse particles (1 to 8 mm) of the original mineral powder, so as to allow the air flow velocity to be increased and the optimized falling time to be maintained, thereby achieving a higher effective volume utilization coefficient.

[0044] The average reduction degree of the mineral powder agglomerates M falling from top to bottom is about 63% in the temperature adjustment zone, about 70% in the high-temperature reduction zone, about 75% in the gas reforming zone, about 80% in the secondary combustion zone, and about 90% in the coke particle spouted fluidized bed zone, which greatly improves the material reduction degree and saves the heat absorbed by the reduction reaction.

[0045] In actual production, all the production parameters described in this article, especially the "around" mentioned above, refer to the fluctuation range of ±10% under relatively conventional or optimized raw material conditions and production conditions. When the raw material conditions and production conditions are relatively special, the fluctuation range will become larger, and even these parameters and their fluctuation ranges should be manually re-optimized to achieve better production results.

[0046] Finally, it should be noted that the above-listed embodiments are only preferred embodiments of the present invention. Of course, those skilled in the art can make changes and modifications to the present invention. If these modifications and variations fall within the scope of the claims of the present invention and their equivalent technologies, they should be considered to be within the scope of protection of the present invention.

Claims

1. A hydrogen-rich, high-oxygen, high-air temperature ironmaking fluidized bed smelting reduction furnace, characterized in that: The fluidized bed smelting reduction furnace is an upward expansion furnace type, including a furnace bottom, a furnace hearth, a furnace belly and a furnace body, wherein the furnace bottom is connected to the lower side of the furnace hearth wall, and the furnace hearth wall is provided with an iron mouth, a furnace hearth coal powder spray gun and a first tuyere; the furnace hearth wall on the upper side of the first tuyere is connected to the lower side of the furnace hearth, and the upper side of the furnace hearth is connected to the furnace body, and the furnace body wall is provided with a lump coal sealing charging port, a second tuyere and an organic spray gun from bottom to top; The angle between the axis of the lump coal sealing charging port and the horizontal plane is 0°~43°; The included angle between the axis of the second tuyere and the horizontal plane is between 0° and 45°, the second tuyere intersects with the inner profile of the furnace wall to form an intersection, the axis of the second tuyere forms a projection line on the cross section of the furnace wall where the intersection is located, and the included angle between the projection line and the radius of the cross section of the furnace wall at the intersection is between 0° and 50°; The angle between the axis of the organic spray gun and the horizontal plane is between 0° and 45°. The organic spray gun intersects with the inner profile of the furnace wall to form an intersection. The axis of the organic spray gun forms a projection line on the cross section of the furnace wall where the intersection is located. The angle between the projection line and the radius of the cross section of the furnace wall at the intersection is between 0° and 50°, so as to form a spiral gas reforming zone J at the lower part of the furnace body. The furnace cavity below the taphole is a dead iron layer, the furnace cavity at the same height as the taphole is a molten iron layer, the furnace cavity between the furnace coal powder spray gun and the taphole is a slag layer, the furnace coal powder spray gun forms a slag iron spring area in the middle of the furnace cavity, the first tuyere sprays oxygen-rich high-temperature air or pure oxygen to form a primary combustion zone in the furnace cavity, and the primary combustion zone is located on the upper surface of the slag layer and the slag iron spring area; The furnace cavity above the slag layer is a coke particle spouted fluidized bed belt, which strengthens the reduction and heat transfer of slag iron and enhances the thermal stability of the furnace.

2. The hydrogen-rich, high-oxygen, high-air-temperature ironmaking fluidized bed smelting reduction furnace according to claim 1, characterized in that: The furnace body is also equipped with an intelligent furnace wall thickness control device.

3. The hydrogen-rich, high-oxygen, high-air-temperature ironmaking fluidized bed smelting reduction furnace according to claim 1, characterized in that: Both the furnace belly and the furnace body are generally expanded structures.

4. The hydrogen-rich, high-oxygen, high-air-temperature ironmaking fluidized bed smelting reduction furnace according to claim 3, characterized in that: The included angle between the inner curved surface generatrix of the furnace belly wall and the horizontal plane is in the range of 0°~87°, and the included angle between the inner curved surface generatrix of the furnace body wall and the horizontal plane is in the range of 25°~90°. The inner profile of the furnace belly and the furnace body is allowed to be composed of more than one cone sections with different generatrix angles, and even the generatrix of the inner profile is allowed to be curved.

5. The hydrogen-rich, high-oxygen, high-air-temperature ironmaking fluidized bed smelting reduction furnace according to claim 1, characterized in that: The angle between the axis of the furnace coal powder spray gun and the horizontal plane is 10°~60°; the angle between the axis of the first tuyere and the horizontal plane is 0°~45°; the furnace coal powder spray gun feeds coal powder into the middle and lower part of the furnace under the action of carrier gas, and the jet directly reaches the molten iron layer, stirring up the slag and iron spring area in the center of the furnace, providing reducing agent for the molten pool and supplementary carburization of the molten iron; the carrier gas is the cold circulating coal gas or nitrogen of this device; or mineral powder or dust removal ash is also added to the coal powder to adjust the oxygen potential of the molten pool, strengthen dephosphorization or inhibit over-reduction of TiO2, and avoid slag and iron from becoming sticky; or the coal powder is also added or even completely replaced with hydrogen, coke oven gas, natural gas, biomass or organic waste organic matter to increase hydrogen-rich or even pure hydrogen reducing agent.

6. The hydrogen-rich, high-oxygen, high-air-temperature ironmaking fluidized bed smelting reduction furnace according to claim 1, characterized in that: Lump coal of 3 to 60 mm in size is added through the sealed lump coal charging port. The lump coal continuously fed into the furnace forms a local lump coal moving bed area on the furnace belly wall, the number of which is equal to the sealed lump coal charging port. During the slow downward movement, it absorbs the radiation heat from the secondary combustion zone and the heat from the furnace gas, and is heated up for dry distillation and coking. After the coke particles are formed, they enter the coke particle spouted fluidized bed zone, and the volatile matter in the coal enters the furnace body gas, thereby improving the hydrogen enrichment effect of the gas.

7. The hydrogen-rich, high-oxygen, high-air-temperature ironmaking fluidized bed smelting reduction furnace according to claim 1, characterized in that: Oxygen-enriched high-temperature air or pure oxygen is then injected from the second tuyere to form a spiral secondary combustion zone at the lower part of the furnace body, thereby enhancing heat transfer and increasing the heat income of the furnace.

8. The hydrogen-rich, high-oxygen, high-air-temperature ironmaking fluidized bed smelting reduction furnace according to claim 1, characterized in that: Hydrogen, coke oven gas, natural gas, 0-6mm biomass or coal powder or organic waste organic matter are sprayed into the organic matter spray gun to increase hydrogen-rich or even pure hydrogen reducing agent; so as to form a spiral gas reforming zone in the lower part of the furnace body, laying the foundation for the enhanced reduction in the upper area.

9. The hydrogen-rich, high-oxygen, high-air-temperature ironmaking fluidized bed smelting reduction furnace according to any one of claims 1 to 8, characterized in that: The furnace wall adopts copper composite cooling wall, the brickwork of the furnace wall above the iron mouth adopts high-density bricks containing zirconium or chromium, other parts adopt cooling equipment and brickwork corresponding to blast furnace, and high-pressure closed circulation soft water is used as cooling medium. Combined with the furnace type and equipment of this reduction furnace, a more stable slag skin protective layer is formed, which greatly improves the ability to resist molten iron scouring.

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