CN115948630A

CN115948630A - Smelting reduction furnace of hydrogen-rich high-oxygen high-air-temperature iron-making fluidized bed

Info

Publication number: CN115948630A
Application number: CN202310009809.XA
Authority: CN
Inventors: 李玉茹; 张灵修; 张松; 克立良; 毕燕
Original assignee: Tangshan Jingyan Co ltd LLC
Current assignee: Tangshan Jingyan Co ltd LLC
Priority date: 2023-01-05
Filing date: 2023-01-05
Publication date: 2023-04-11

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 of an upper expansion furnace type and comprises a furnace hearth, a furnace belly and a furnace body, wherein the wall of the furnace hearth is provided with an iron notch, a furnace hearth coal powder spray gun and a first air port, the wall of the furnace hearth on the upper side of the first air port is connected with the lower side of the furnace belly, the upper side of the furnace belly is connected with the furnace body, and the wall of the furnace body is provided with a lump coal sealing charging port, a second air port and an organic matter spray gun; the hydrogen-rich or even pure hydrogen reducing agent is added, after the pre-reduction is completed by various devices positioned right above the device, the mineral powder is bonded into mineral powder aggregates with the size of about 3mm, and the mineral powder aggregates are directly discharged into the melting reduction furnace, and are continuously heated, reduced, bonded and grown in the subsequent falling process until the mineral powder aggregates are completely melted, so that the trouble of a blast furnace soft melting zone is avoided, the FeO content in slag and the corrosion action thereof are reduced, the total heat consumption of a molten pool is saved, and the temperature of slag iron is increased.

Description

Smelting reduction furnace of hydrogen-rich high-oxygen high-air-temperature iron-making fluidized bed

Technical Field

The invention relates to the technical field of smelting reduction furnaces, in particular to a smelting reduction furnace of a hydrogen-rich high-oxygen high-air-temperature iron-making fluidized bed.

Background

Smelting reduction and direct reduction methods are commonly adopted in the iron making process of fine ores, and one problem of the iron ore fluidized bed smelting reduction process at present is how to economically provide high-temperature, high-melting-rate and high-reduction-degree iron ore powder for a smelting reduction furnace.

Guohongjie and Li Lin, university of Beijing science and technology, issued a future of non-coking coal ironmaking process and equipment, and analyzed Finex, HIsarna and HIsmelt, indicating that Finex is the only process which can stably realize large-scale production, and the advantages of the process are that coal gas generated by a final reduction furnace is reformed to remove CO ₂ Then enters the fluidized bed, so that the pre-reduction degree of the fluidized bed is improved. The granularity of the used mineral powder is 0-8 mm, the average grain size is 0.90-3.64 mm, and the proportion of-0.125 mm is 4.9-12.68%, the coarse mineral powder plays a great role in reducing the cohesive flow loss in the fluidized bed reduction process, but the cohesive flow loss can not be completely solved, and the cohesive flow loss still has great threat to the production stability. The heat consumption and the cost of the process are additionally increased by the pre-reduced iron powder hot-pressed block of the Finex process; the smelting reduction furnace is basically consistent with the Corex process, 180-230 kg/t of iron coke or briquette needs to be added, and the sealing and the material distribution under the high-temperature condition are difficult to reach the level of a blast furnace. In fact, the Corex process, the Finex process, the hydrogen-rich oxygen-rich blast furnace and other processes, the problem of air impermeability in the process of the pre-reduction ore softening and melting, the softening and melting zone of which adds great trouble to the processes, have to use a coke framework and a coke window for ventilation, not only increase the dependence on high-quality coke, the related pollution, the cost and the resource risk, but also further strengthen the huge obstacle of smelting by the processes.

For research and development and scale production of a smelting reduction furnace, publication numbers CN108251588A, CN112280922A, CN1926248A and CN101473048A all disclose improvement and exploration work of an SRV furnace of a HIsmelt process, and through obliquely inserting mineral powder, a coal powder spray gun and a top-blowing high-temperature oxygen-enriched spray gun which are immersed in a slag layer, liquid iron slag fountain, splashes and a slag layer in the center of a molten pool are effectively heated at a large secondary combustion rate, so that the ultrahigh reduction speed of FeO in liquid slag in the SRV furnace and the huge heat supply capacity of secondary combustion are verified under quite severe production conditions (the pre-reduction degree of the rotary kiln mineral powder is 15-23 percent, and the preheating temperature is about 400 ℃), the high-temperature state of the molten pool is continuously maintained, and stable continuous industrial scale production is realized. However, such huge amount of FeO reduction, heat demand and high temperature exhaust gas physical heat in SRV furnace also limit further reduction of energy consumption and production cost of current HIsmelt process. The pneumatic conveying of the pre-reduced ore powder also increases the heat consumption and the cost.

The beneficial improvement to the HIsmelt process at present, more valuable is HIsarna process, reported in the text of breakthrough iron-making technology in the ultra-low carbon steel-making project, a cyclone melting reduction furnace is arranged on the vault of the SRV furnace, and normal temperature mineral powder, solvent and oxygen are fed into the cyclone section at the place together, the coal gas of the SRV furnace is almost completely combusted, the high temperature of about 1571.3 ℃ is generated, physical water evaporation, crystal water and carbonate decomposition and polymerization melting are rapidly completed, the temperature is raised to about 1450 ℃, and the pre-reduction degree of about 20 percent is reached through thermal decomposition and reduction, and the great advantage is that the quite high production efficiency can be reached; the central oxygen-enriched hot air spray gun is changed into a plurality of pure oxygen spray guns inserted obliquely from the vault, so that the secondary combustion rate is about 42.9 percent, the working capacity of a molten pool of the Niolon HIsmelt process is maintained, the total heat income is greatly improved and the reduction amount is saved compared with an SRV furnace molten pool of the HIsmelt process, better production indexes are expected to be obtained compared with the Niolon HIsmelt process, even the production indexes are close to or lower than the energy consumption amount of a blast furnace body, and although the pre-reduction degree is still to be improved, the pre-reduction degree of the mineral powder is continuously improved, and great difficulty is met.

CN102690919A discloses a flash metallurgy method for iron, the physical heat carried by dry iron ore powder, fuel and oxygen in the reaction tower is too little, and the flue gas passing through the upper part of the high-temperature molten pool is recovered by a reburning type waste heat boiler, the efficiency is not satisfactory, and the total fuel consumption of the whole process can be increased.

For smelting reduction furnaces or iron bath furnaces with different processes, how to economically improve the preheating temperature and the reduction degree of ore powder, particularly how to reduce the resistance of materials to airflow in the reflow process by matching with a pre-reduction device, and even in the aspects of reducing gas preparation and supply, pre-reduction material transportation, service life and reliability of a smelting reduction furnace body and equipment and the like, the problems of different degrees exist, so that additional heat consumption and cost are increased.

Disclosure of Invention

In order to solve the technical problems, the invention provides a hydrogen-rich high-oxygen high-air-temperature iron-making fluidized bed smelting reduction furnace, which avoids heat dissipation loss as much as possible and improves production efficiency, energy utilization rate, operation reliability and stability.

In order to realize the technical purpose, the invention adopts the following scheme: the smelting reduction furnace is of an upper expansion furnace type and comprises a furnace bottom, a furnace hearth, a furnace belly and a furnace body, wherein the furnace bottom is connected with the lower side of a furnace hearth wall body, and the furnace hearth wall body is provided with an iron notch, a furnace hearth coal powder spray gun and a first air port; the furnace hearth wall body on the upper side of the first air port is connected with the lower side of the furnace bosh, the upper side of the furnace bosh is connected with the furnace body, and the furnace body wall body is provided with a lump coal sealing feed opening, a second air port and an organic matter spray gun.

Compared with the prior art, the invention has the beneficial effects that: the ore powder is preheated, pre-reduced and bonded into ore powder granules with the particle size of more than 3mm, and the ore powder granules are directly discharged into a melting reduction furnace, and are continuously heated, reduced and bonded to grow in the subsequent drifting process until the ore powder granules are completely melted, so that the trouble of a blast furnace soft melting zone is avoided, the FeO content and the corrosion action of the FeO content in slag are reduced, the total heat consumption of a melting pool is saved, and the temperature of iron slag is increased.

The preferred scheme of the invention is as follows:

the furnace body is also provided with an intelligent furnace wall junction thickness control device.

Both the furnace bosh and the furnace shell are of an overall expanding structure.

The included angle between the inner curved surface generatrix of the furnace belly wall and the horizontal plane ranges from 0 degree to 87 degrees, the preferred range is from 0 degree to 45 degrees, the included angle between the inner curved surface generatrix of the furnace shell wall and the horizontal plane ranges from 25 degrees to 90 degrees, and the preferred range is from 70 degrees to 87 degrees. The inner shapes of the furnace bosh and the furnace body allow more than one conical section with different generatrix angles to be adopted for composition, and even the generatrix of the inner shapes of the furnace bosh and the furnace body allows a curve to be adopted.

The hearth cavity below the taphole is a dead iron layer, the hearth cavity with the taphole at the same height is a molten iron layer, the hearth cavity between the hearth pulverized coal spray gun and the taphole is a slag layer, the hearth pulverized coal spray gun forms a slag iron spring area in the middle of the hearth cavity, the first air port forms a primary combustion zone in the hearth cavity, and the primary combustion zone is located on the upper surface of the slag layer and the slag iron spring area. The average temperature of the slag layer is up to 1550-1650 ℃, coarse-grained coal powder (0-6 mm) is sprayed in the slag layer, the jet flow can reach a molten iron layer so as to ensure the carburization of molten iron and the reduction of FeO in the slag, the content of FeO in the slag is about 1 percent, the average temperature of the molten iron layer is stabilized at 1430-1550 ℃, and the surface temperature of the carbon brick is stabilized at 1050 ℃ by cooling the furnace bottom (similar to the furnace bottom of a blast furnace) so as to prevent the erosion of the carbon brick.

The included angle between the axis of the furnace hearth coal powder spray gun and the horizontal plane is 10-60 degrees, and preferably 15-45 degrees. The sprayed coarse-grained coal powder with the particle size of 0-6 mm provides a reducing agent for a molten pool and molten iron is supplemented with carburization, carrier gas is cold circulating coal gas in the process, nitrogen or superheated steam is only used as safety purging gas, safety is guaranteed, introduction of nitrogen is reduced, and nitrogen or superheated steam can also be used as carrier gas. The jet flow of the slag-forming agent directly reaches a molten iron layer, so that a slag-forming iron fountain area is stirred in the center of a molten pool, and the mass transfer and heat transfer of a hearth and various reaction speeds of the hearth are enhanced; the coal powder can also be added with a small amount of mineral powder or dedusting ash for adjusting the oxygen potential of a molten pool, strengthening dephosphorization or inhibiting TiO ₂ The slag iron is prevented from becoming sticky through over-reduction; the coal powder can also be added with organic matters such as hydrogen, coke oven gas, natural gas, biomass or organic garbage and the like or even completely substituted, and a hydrogen-rich or even pure hydrogen reducing agent is added, wherein the hydrogen-rich refers to that the hydrogen content of the coal gas generated after the coke oven gas, the natural gas, the biomass or the organic garbage and volatile components in the coal powder enter the device is greatly improved compared with that of blast furnace gas.

The hearth cavity above the slag layer is a coke particle spouted fluidized bed zone. After the lump coal enters the furnace from the upper edge of the furnace belly, the lump coal is heated and dry distilled in the process of moving to the furnace cylinder, and the lump coal is converted into coke particles, and the coke particles are violently combusted with hot air with high air temperature and oxygen enrichment of more than or equal to 30% at the temperature of about 1200 ℃ of a first tuyere or normal-temperature pure oxygen.

The included angle between the axis of the first tuyere and the horizontal plane is 0-45 degrees, and preferably 0-30 degrees. The focal point temperature of the primary combustion zone exceeds about 2100 ℃, and is close to the surface of a slag layer and a gushing region of slag iron, so that sufficient high-temperature heat is provided for a molten pool, liquid slag iron which drops from the top and enters a coke particle spouted fluidized bed zone and high-viscosity creeping slag iron which slowly flows down along the furnace wall are quickly heated and reduced at the position and are completely melted, the average reduction degree reaches about 90 percent, the high-temperature heat income of the molten pool is improved, the total direct reduction amount of the molten pool is saved, and the heat stability of the molten pool is improved. The coal gas, the furnace hearth coal powder spray gun carrier gas and the coal powder cracking substance generated by various reactions in the molten pool and the combustion products of the first tuyere provide sufficient fluidization and spouting medium for the coke particle spouted fluidized bed belt, ensure the active state of the six-phase high-temperature spouted fluidized bed (gas phase, liquid iron phase, liquid slag phase, foam slag phase, solid coke particles and trace solid ore blocks), improve the air permeability and liquid permeability, stabilize the average temperature of the main bed layer of the coke particle spouted fluidized bed belt at 1650-1800 ℃ and have the overall properties superior to the combustion zone and the dripping zone of the blast furnace.

The included angle between the axis of the lump coal sealing feed inlet and the horizontal plane is 0-43 degrees; the edge part of the furnace chamber body obliquely below the lump coal sealing feed port forms a local coal moving bed area. In order to improve the thermal stability of the high-temperature zone of the smelting reduction furnace, lump coal with the size of 3-60 mm is added from a lump coal sealed charging port, the lump coal continuously fed into the furnace is on the furnace belly wall to form a partial lump coal moving bed pile with the number equal to that of the lump coal sealed charging port, in the process of slow downward movement, the radiation heat of a secondary combustion zone and the heat of gas in a furnace cylinder are absorbed, the temperature is raised, the carbonization and the coking are carried out, after coke particles are formed, the coke particles enter a coke particle spouted fluidized bed zone, and the volatile components in the coal enter the furnace body gas, so that the hydrogen-rich effect of the gas is improved.

The included angle between the axis of the second tuyere and the horizontal plane is 0-45 degrees, the second tuyere and the inner profile of the furnace wall are intersected to form an intersection point, the axis of the second tuyere forms a projection line on the cross section of the furnace wall where the intersection point is located, and the included angle between the projection line and the radius of the cross section of the furnace wall at the intersection point is 0-50 degrees, so that a spiral secondary combustion zone is formed at the lower part of the furnace body.

The included angle between the axis of the organic matter spray gun and the horizontal plane is 0-45 degrees, the organic matter spray gun and the inner profile of the furnace wall are intersected to form an intersection point, the axis of the organic matter spray gun forms a projection line on the cross section of the furnace wall where the intersection point is located, and the included angle between the projection line and the radius of the cross section of the furnace wall at the intersection point is 0-50 degrees, so that a spiral coal gas reforming belt is formed at the lower part of the furnace body. The organic matter spray gun is tangent to a virtual circle with the diameter of 10-50% of the inner diameter of the furnace shape in a clockwise mode to form a clockwise spiral airflow field (or anticlockwise), and hydrogen, coke oven gas, natural gas, biomass or coal powder or organic matter garbage organic matter with the diameter of 0-6 mm is sprayed into the clockwise spiral airflow field, so that hydrogen-rich or even pure hydrogen reducing agent is added. So as to form a spiral coal gas reforming zone at the lower part of the furnace body, complete the reforming of the coal gas by utilizing the volatile components of the coal and carbon granules or other organic matters, provide good high-temperature coal gas with high reduction potential for subsequent fluidized bed reduction, avoid the reduction of the heat value and the heat loss of the coal gas, simultaneously pass through the ore aggregates with high reduction degree (about 4 mm) in the area, a considerable part of the ore aggregates are melted and further bonded and polymerized, and the average reduction degree is further improved to about 75 percent.

Drawings

FIG. 1 is a schematic longitudinal sectional view of a hydrogen-rich high-oxygen high-blast-temperature ironmaking fluidized bed smelting reduction furnace according to an embodiment of the present invention;

labeled as: 1. a foundation; 11. a furnace bottom; 12. a hearth; 13. a furnace belly; 14. a furnace body; 2. tapping; 3. a furnace hearth pulverized coal spray gun; 4. a first tuyere; 5. sealing a feed inlet by using lump coal; 6. a second tuyere; 7. an organic matter spray gun; 8. an intelligent furnace wall junction thickness control device; 9. a cold circulation gas distribution pipe.

Detailed Description

The present invention will be described in detail with reference to the following embodiments in order to fully understand the objects, features and effects of the invention, but the present invention is not limited thereto.

As shown in figure 1, the smelting reduction furnace of the hydrogen-rich high-oxygen high-air-temperature iron-making fluidized bed provided by the invention is of an upper expansion furnace type, and comprises a foundation 1, a furnace bottom 11, a furnace hearth 12, a furnace belly 13, a furnace body 14 and the like, wherein an iron notch 2, a furnace hearth coal powder spray gun 3 and a first air port 4 are arranged on the wall body of the furnace hearth 12, the wall body of the furnace hearth 12 on the upper side of the first air port 4 is connected with the lower side of the furnace belly 13, the upper side of the furnace belly 13 is connected with the furnace body 14, and the wall body of the furnace body 14 is provided with a lump coal sealing feed port 5, a second air port 6, an organic matter spray gun 7 and an intelligent furnace wall junction thickness control device 8. Various pre-reduction devices can be arranged above the fluidized bed smelting reduction furnace.

The included angle between the inner curved surface generatrix of the furnace belly 13 wall and the horizontal plane is 0-87 degrees, and the preferable range is 0-45 degrees; the included angle between the inner curved surface generatrix of the wall body of the furnace shell 14 and the horizontal plane is 25-90 degrees, and the preferable range is 70-87 degrees. The internal shape of the furnace bosh 13 and the furnace shell 14 allows for the use of more than one conic section with different generatrix angles, even the generatrix of the internal shape allows for the use of curves.

The wall body of the hearth 12 adopts a red copper composite cooling wall, the bricks of the wall body of the hearth 12 above the taphole 2 adopt high-density bricks containing zirconium or chromium, the cooling equipment and the bricks of the corresponding blast furnace are adopted at other parts, high-pressure closed circulating soft water is adopted as a cooling medium, and the furnace type, the organic matter spray gun, the taphole, the intelligent furnace wall junction thickness control device, the sealed charging hole, the tuyere and other structures of the reduction furnace are matched to form a more stable slag crust protective layer together with the furnace wall, so that the capability of resisting molten iron scouring is greatly improved, the supercooled film state boiling state is avoided, and the service life is prolonged.

More preferably, the furnace wall of the fluidized bed smelting reduction furnace is provided with 1 to 4 tapholes 2 and one to three rows of furnace cylinder coal powder spray guns 3 from bottom to top, each row of the furnace cylinder coal powder spray guns 3 comprises one to more sets of furnace cylinder coal powder spray guns 3, two to more sets of first tuyeres 4, two to more sets of lump coal sealing feed inlets 5 and one to three rows of second tuyeres 6, each row of the furnace cylinder coal powder spray guns comprises two to more sets of second tuyeres 6 and two to three rows of organic matter spray guns 7, each row of the furnace cylinder coal powder spray guns 7 comprises at least one organic matter spray gun 7 and three to more rows of intelligent furnace wall junction thickness control devices 8, each row of the furnace wall junction thickness control devices 8 and other auxiliary equipment, the furnace cylinder coal powder spray guns 3 and the organic matter spray guns 7 are patent technologies (publication number CN 114018058B) already granted by the applicant, and the intelligent furnace wall junction thickness control devices 8 are patent technologies (publication number CN 114812211B) already granted by the applicant.

The fixing and sealing structure of each tuyere, spray gun and charging opening device selects the structural idea similar to three sets of tuyere of a blast furnace or other fixing and sealing structures so as to be convenient for assembly and disassembly; the discharge of the slag and the iron also adopts mature devices and technologies of a taphole device, a tapping machine, a mud gun, a slag-iron separator and the like of the blast furnace, and the details are not repeated herein.

The hearth of the smelting reduction furnace of the hydrogen-rich high-oxygen high-air-temperature ironmaking fluidized bed formed by the 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 spouted fluidized bed area X, a local lump coal moving bed area Y, a secondary combustion area Z, a coal gas reforming area J, a high-temperature reduction area K and a temperature adjusting area N from bottom to top.

The furnace hearth 12 cavity below the taphole 2 is a dead iron layer S, the furnace hearth 12 cavity between the taphole 2 and the taphole 2 is a molten iron layer T, the furnace hearth cavity between the furnace hearth pulverized coal spray gun 3 and the taphole 2 is a slag layer U, the furnace hearth pulverized coal spray gun 3 forms a slag iron gushing region V at the center of the furnace hearth 12 cavity, the first air port 4 forms a primary combustion zone W in the furnace hearth 12 cavity, and the primary combustion zone W is located on the upper surfaces of the slag layer U and the slag iron gushing region V.

The included angle between the axis of the furnace hearth coal powder spray gun 3 arranged on the slag layer U and the horizontal plane is 10-60 degrees, and preferably 15-45 degrees. The sprayed coarse coal powder with the particle size of 0-6 mm and the carrier gas are cold circulating coal gas in the process, so that the safety is ensured, and the introduction of nitrogen is reduced. The jet flow is directed to the molten iron layer T, thereby stirring the slagging iron fountain area V at the center of the molten pool, and enhancing the mass and heat transfer of the hearth 12 and various reaction speeds thereof. The coal powder can also be added with a small amount of mineral powder or dedusting ash for adjusting the oxygen potential of a molten pool, strengthening dephosphorization or inhibiting TiO ₂ The slag iron is prevented from becoming sticky through over-reduction; the coal powder can also be added with organic matters such as hydrogen, coke oven gas, natural gas, biomass or organic garbage and the like, and hydrogen-rich or even pure hydrogen reducing agents are added.

The average temperature of the slag layer U is up to 1550-1650 ℃, organic matters such as coarse-grained coal powder (0-6 mm) and hydrogen are sprayed in the slag layer U, the jet flow can reach a molten iron layer T so as to ensure the carburization of molten iron and the reduction of FeO in the slag, the content of FeO in the slag is about 1 percent, the average temperature of the molten iron layer T is stabilized at 1430-1550 ℃, and the furnace bottom 11 is cooled so that the surface temperature of the carbon brick is stabilized at 1050 ℃ to prevent the erosion of the carbon brick. The working state of the process is closer to that of blast furnace hearths and Corex and Finex hearths, compared with HIsarna and HIsmelt, the total reduction amount (about 4 percent) and the heat demand of FeO in the slag are greatly saved, the loss of valuable elements such as iron and the like along with the slag is avoided, and if high phosphorus ore or vanadium-titanium ore is treated, part of dust removal ash or mineral powder at the furnace top of the process can be sprayed from the slag, so that the oxygen potential of a slag iron layer is increased, and over-reduction is avoided.

The cavity of the furnace hearth 12 above the slag layer U is a coke particle spouted fluidized bed zone X. Lump coal enters a coke particle spouted fluidized bed zone X of a furnace hearth 12 (synchronous dry distillation) and is violently combusted with hot air with the high-temperature oxygen enrichment of more than or equal to 30 percent at 1200 ℃ of a first tuyere 4 or pure oxygen at normal temperature.

The included angle between the axis of the first tuyere 4 and the horizontal plane is 0-45 degrees, and preferably 0-30 degrees. The focal point temperature of the primary combustion zone W is about 2100 ℃, and is close to the surface of a slag iron spring zone V and a slag layer U, so that sufficient high-temperature heat is provided for a molten pool, liquid slag iron which drips from the top and enters a coke particle spouted fluidized bed zone X and high-viscosity peristaltic slag iron which slowly flows downwards along a furnace wall is rapidly heated and reduced and is completely melted, the average reduction degree reaches about 90%, the high-temperature heat income of the molten pool is improved, the direct reduction total amount of the molten pool is saved, the thermal stability of the molten pool is improved, the average temperature of the slag layer U is stabilized at 1550-1650 ℃, the average temperature of a molten iron layer T is stabilized at 1430-1550 ℃, and the surface temperature of carbon bricks is stabilized at 1050 ℃ by cooling the furnace bottom to prevent the carbon bricks from being corroded. The coal gas, the furnace hearth coal powder spray gun carrier gas and the organic matter or coal powder cracking substance generated by various reactions in the molten pool and the combustion product of the first tuyere provide sufficient fluidizing and spraying medium for the coke particle spouted fluidized bed belt X, ensure the active state of the six-phase high-temperature spouted fluidized bed (gas phase, liquid iron phase, liquid slag phase, foam slag phase, solid coke particles and trace solid ore blocks), improve the air permeability and liquid permeability, and stabilize the main bed layer temperature of the coke particle spouted fluidized bed belt at 1650-1800 ℃.

The included angle between the axis of the lump coal sealing feed opening 5 and the horizontal plane is 0-43 degrees; the edge part of the cavity of the furnace belly 13 obliquely below the lump coal sealing feed opening 5 forms a local coal moving bed area Y. In order to improve the thermal stability of a high-temperature zone of the smelting reduction furnace, 3-60 mm lump coal is added from a lump coal sealing feed port 5, the lump coal continuously fed into the furnace is on a furnace belly 13 wall body to form a local lump coal moving bed zone Y with the number equal to that of the lump coal sealing feed port 5, in the process of slow downward movement, the radiant heat of a secondary combustion zone and the heat of furnace cylinder coal gas are absorbed, the temperature is raised and the carbonization is carried out to obtain coke particles, the coke particles enter a coke particle spraying fluidized bed zone X, the coke particles and high-air temperature air with the oxygen enrichment of 1200 ℃ of a first air port 4 (the oxygen content is more than or equal to 30 percent) or normal-temperature pure oxygen are subjected to violent primary combustion, the volatile components in the coal enter furnace body coal gas, and the hydrogen enrichment effect of the coal gas is improved.

The included angle between the axis of the second tuyere 6 and the horizontal plane is 0-45 degrees, the second tuyere 6 and the inner shape of the furnace wall are intersected to form an intersection point, the axis of the second tuyere 6 forms a projection line on the cross section of the furnace wall where the intersection point is located, and the included angle between the projection line and the radius of the cross section of the furnace wall at the intersection point is 0-50 degrees, so that a spiral secondary combustion zone is formed at the lower part of the furnace body 14.

The second tuyere 6 is tangent clockwise to a virtual circle with the diameter of 10-50% of the inner diameter of the furnace to form a clockwise spiral airflow field (anticlockwise), so that hot air with high air temperature and oxygen enrichment of more than or equal to 30% or normal temperature pure oxygen is sprayed at 1200 ℃, the secondary combustion focal point of the gas in the molten pool reaches about 2200 ℃, and strong high-temperature heat is provided for the molten pool. Meanwhile, the ore aggregates with high reduction degree passing through the area are mostly melted and further bonded and polymerized into larger liquid drops (about 5 mm), the temperature is preheated to about 1550 ℃, the reduction and reoxidation of the ore in the area coexist, and the average reduction degree of the whole ore is slightly increased by about 80 percent due to the smaller oxidation area. High CO of secondary combustion zone Z ₂ The average temperature of the coal gas is as high as 1800 ℃ after the ore pellets are preheated, and the high-temperature heat is suitable for reforming the coal gas.

The included angle between the axis of the organic matter spray gun 7 and the horizontal plane is 0-45 degrees, the organic matter spray gun 7 and the inner profile of the furnace wall are intersected to form an intersection point, the axis of the organic matter spray gun 7 forms a projection line on the cross section of the furnace wall where the intersection point is located, and the included angle between the projection line and the radius of the cross section of the furnace wall at the intersection point is 0-50 degrees, so that a spiral coal gas reforming belt J is formed at the lower part of the furnace body 14. The organic matter spray gun 7 is tangent clockwise to a virtual circle with the diameter of 10-50% of the inner diameter of the furnace shape, a clockwise spiral airflow flow field (anticlockwise) is formed, organic matters such as hydrogen, coke oven gas, natural gas, 0-6 mm biomass or coal dust or organic matter garbage and the like are sprayed into the clockwise spiral airflow flow field, a hydrogen-rich or even pure hydrogen reducing agent is added, the coal gas is reformed by utilizing volatile components and carbon particles of coal or other organic matters, high-temperature coal gas with good high reduction potential is provided for subsequent fluidized bed reduction, the reduction of the heat value of the coal gas and the heat loss are avoided, meanwhile, ore aggregates with high reduction degree (about 4 mm) pass through the area, a considerable part of the coal aggregates are melted and further bonded and polymerized, and the average reduction degree is further improved to about 75%.

In the middle upper part of the furnace body 14, reformed coal gas enters a high-temperature reduction zone K, mineral powder aggregates which uniformly float from top are continuously reduced and heated in the high-temperature reduction zone K, so that the average temperature of the mineral powder aggregates reaches about 950 ℃, fine mineral powder is continuously bonded and polymerized, the average particle size reaches about 3mm, the mineral powder is softened, and the average reduction degree reaches about 70%.

Along with the reduction of the average temperature of the coal gas, more than three rows of intelligent furnace wall knot thickness control devices are densely arranged on the wall body of the furnace body 14 so as to control the knot thickness and knots of the furnace wall.

A temperature adjusting zone N is designed above the high-temperature reducing zone K, a cold circulating coal gas distribution pipe 9 is arranged on a furnace body wall body at the height of the temperature adjusting zone N, cold circulating coal gas produced by the process is introduced, and the high-temperature coal gas H is cooled to 800-900 ℃ and 700-850 ℃ twice to meet the coal gas temperature requirement of a pre-reducing large-speed-difference stirring spouted fluidized bed arranged above the high-temperature reducing zone K. The average temperature of the mineral powder aggregates M in the temperature adjusting zone is increased by 30-80 ℃, and the average reduction degree is increased by about 3%.

In a smelting reduction furnace with a coke particle spouted fluidized bed above, on the vertical motion velocity component, the relative velocity and direction of mineral powder aggregates or liquid drops and a furnace body are approximately equal to the difference between the terminal settling velocity and the air velocity, the air velocity (relative to the furnace body) is slightly lower than that of a fast fluidized bed and higher than that of a turbulent fluidized bed, the smelting reduction furnace belongs to a dilute phase fluidized bed, the air flow is a spiral rotating flow field (various spray gun jet flows have certain tangential angles and can be both clockwise or anticlockwise spiral flow fields), and in the fluidized state, part of the small-particle size aggregates or liquid drops can be wrapped by the air flow to move upwards, and part of the small-particle size aggregates or liquid drops can be bonded and grown up through collision; and the large-particle-size mineral powder granules or large liquid drops move downwards, so that the method is an ideal countercurrent heat transfer and reaction process, and is favorable for improving the energy utilization rate. More importantly, the softening and melting process of the mineral powder aggregates is completed in a dilute phase fluidized bed of a high-temperature spiral airflow flow field, airflow resistance is not increased, and the negative effect of a blast furnace reflow zone (moving bed) is thoroughly eliminated. One of the core theoretical innovation points of the invention is that the mineral powder is promoted to be bonded into granules and the granules grow up by utilizing the bonding phenomenon of the mineral powder, and the air velocity is allowed to be improved and the optimized falling time is maintained only by assisting the proper proportion of coarse particles (1-8 mm) of the original mineral powder, so that the higher effective volume utilization coefficient can be achieved.

The average reduction degree of the mineral powder granules M falling from top to bottom is about 63% in the temperature adjusting zone, the average reduction degree of the high-temperature reducing zone reaches about 70%, the average reduction degree of the coal gas reforming zone is improved to about 75%, the average reduction degree of the secondary combustion zone is improved to about 80%, the average reduction degree of the coke particle spouted fluidized bed zone is improved to about 90%, the reduction degree of the materials is greatly improved, and the heat absorption capacity of the reduction reaction is saved.

In actual production, all the production parameters described herein, particularly the "left and right" refers to the fluctuation range of ± 10% under the condition of relatively conventional or optimized raw fuel conditions and production conditions, and when the raw fuel conditions and production conditions are relatively special, the fluctuation range will become larger, and even the parameters and the fluctuation range thereof should be manually re-optimized to achieve better production effect.

Finally, it is noted that: the above-mentioned list is only the preferred embodiment of the present invention, and naturally those skilled in the art can make modifications and variations to the present invention, which should be considered as the protection scope of the present invention provided they are within the scope of the claims of the present invention and their equivalents.

Claims

1. A fluidized bed smelting reduction furnace for hydrogen-rich high-oxygen high-air-temperature iron making is characterized in that the fluidized bed smelting reduction furnace is of an upper expansion furnace type and comprises a furnace bottom, a furnace hearth, a furnace belly and a furnace body, wherein the furnace bottom is connected with the lower side of a furnace hearth wall body, and the furnace hearth wall body is provided with an iron notch, a furnace hearth coal powder spray gun and a first air port; the furnace hearth wall body on the upper side of the first air port is connected with the lower side of the furnace bosh, the upper side of the furnace bosh is connected with the furnace body, and the furnace body wall body is provided with a lump coal sealing feed opening, a second air port and an organic matter spray gun.

2. The fluidized bed smelting reduction furnace for hydrogen-rich and oxygen-rich high-blast-temperature ironmaking according to claim 1, wherein the furnace body is further provided with an intelligent furnace wall thickness control device.

3. The fluidized bed smelting reduction furnace for hydrogen-rich, high-oxygen, high-blast temperature ironmaking according to claim 1, wherein both the belly and the shaft are of a generally expanding type structure.

4. The smelting reduction furnace of the hydrogen-rich high-oxygen high-air-temperature ironmaking fluidized bed according to claim 3, wherein an included angle between a furnace belly wall inner-type curved surface bus and a horizontal plane ranges from 0 degree to 87 degrees, an included angle between a furnace body wall inner-type curved surface bus and the horizontal plane ranges from 25 degrees to 90 degrees, more than one conical section with different bus angles is allowed to be adopted for the inner types of the furnace belly and the furnace body, and even a curve is allowed to be adopted for the inner type bus.

5. The smelting reduction furnace of the hydrogen-rich high-oxygen high-air-temperature iron-making fluidized bed according to claim 1, wherein the hearth cavity below the taphole is a dead iron layer, the hearth cavity at the same height as the taphole is an iron melt layer, the hearth cavity between the hearth pulverized coal injection lance and the taphole is a slag layer, the hearth pulverized coal injection lance forms a slag iron spring region in the middle of the hearth cavity, the first tuyere injects oxygen-rich high-air-temperature air or pure oxygen to form a primary combustion zone in the hearth cavity, and the primary combustion zone is located on the upper surfaces of the slag layer and the slag iron spring region.

6. The smelting reduction furnace of the hydrogen-rich high-oxygen high-air-temperature iron-making fluidized bed according to claim 1, wherein an included angle between the axis of the hearth coal powder spray gun and the horizontal plane is 10-60 degrees; the included angle between the axis of the first tuyere and the horizontal plane is 0-45 degrees; feeding coal powder into the middle lower part of the hearth by a hearth coal powder spray gun under the action of carrier gas, enabling jet flow to reach a molten iron layer, stirring at the center of the hearth to form a slag iron spring area, and providing a reducing agent and molten iron for a molten pool to supplement carburization; the carrier gas is cold circulating coal gas or nitrogen of the device; or the coal powder is also added with mineral powder or dedusting ash for regulating the oxygen potential of a molten pool, strengthening dephosphorization or inhibiting TiO ₂ The slag iron is prevented from being sticky through over reduction; or the coal powder is also added with organic matters such as hydrogen, coke oven gas, natural gas, biomass or organic garbage, and even completely replaces the organic matters, so that the hydrogen-rich or even pure hydrogen reducing agent is added.

7. The smelting reduction furnace of claim 5, wherein the hearth cavity above the slag layer is a fluidized bed zone for blowing coke particles, thereby enhancing the reduction and heat transfer of the slag iron and enhancing the thermal stability of the hearth.

8. The smelting reduction furnace of the hydrogen-rich high-oxygen high-air-temperature iron-making fluidized bed according to claim 1, wherein an included angle between the axis of the lump coal seal charging port and the horizontal plane is 0-43 degrees; lump coal with the size of 3-60 mm is added from a lump coal sealed charging port, the lump coal continuously fed into the furnace forms a local lump coal moving bed area with the number equal to that of the lump coal sealed charging port on the furnace belly wall, in the process of slow downward movement, the heat of radiation heat of a secondary combustion zone and the heat of gas in a furnace cylinder are absorbed, the temperature is raised, the carbonization and the coking are carried out, after coke particles are formed, the coke particles enter a coke particle spraying fluidized bed zone, and the volatile components in the coal enter the furnace body gas, so that the hydrogen-rich effect of the gas is improved.

9. The smelting reduction furnace of the hydrogen-rich high-oxygen high-air-temperature iron-making fluidized bed according to claim 1, wherein an included angle between the axis of the second tuyere and the horizontal plane is 0-45 degrees, the second tuyere and the inner shape of the furnace wall are intersected to form an intersection point, the axis of the second tuyere forms a projection line on the cross section of the furnace wall where the intersection point is located, and the included angle between the projection line and the radius of the cross section of the furnace wall at the intersection point is 0-50 degrees, so that oxygen-rich high-air-temperature air or pure oxygen is sprayed in, a spiral secondary combustion zone is formed at the lower part of the furnace body, heat transfer is enhanced, and heat income of the furnace cylinder is increased.

10. The smelting reduction furnace of the hydrogen-rich high-oxygen high-air-temperature iron-making fluidized bed according to claim 1, wherein an included angle between the axis of the organic matter spray gun and the horizontal plane is 0-45 degrees, the organic matter spray gun and the inner shape of the furnace wall are intersected to form an intersection point, the axis of the organic matter spray gun forms a projection line on the cross section of the furnace wall where the intersection point is located, the included angle between the projection line and the radius of the cross section of the furnace wall at the intersection point is 0-50 degrees, hydrogen, coke oven gas, natural gas, biomass or coal powder or organic matter garbage organic matter with the diameter of 0-6 mm is sprayed in the projection line, and hydrogen-rich or even pure hydrogen reducing agent is added; so as to form a spiral coal gas reforming belt at the lower part of the furnace body and lay a foundation for the strengthening reduction of the upper area.

11. The smelting reduction furnace of the hydrogen-rich high-oxygen high-blast-temperature ironmaking fluidized bed according to any one of claims 1 to 10, wherein a hearth wall body adopts a red copper composite cooling wall, bricks of the hearth wall body above an iron notch adopt high-density bricks containing zirconium or chromium, other parts adopt cooling equipment and bricks corresponding to a blast furnace, high-pressure closed circulating soft water is adopted as a cooling medium, and a furnace shape and a device of the reduction furnace are matched to form a more stable cinder cover protective layer, so that the capability of resisting molten iron scouring is greatly improved; the fixed and sealed structure of each tuyere, spray gun and charging opening device selects the structure idea similar to three sets of blast furnace tuyere or other fixed and sealed structures to facilitate assembly and disassembly; the discharge of slag and iron also adopts a mature device and technology of a blast furnace; the maturity and the running stability of the invention are increased.