Magnetic control green hydrogen flash reduction hematite smelting device and use method

Abstract

A device for smelting hematite through magnetic control green hydrogen flash reduction comprises a magnetic controller, a powder bin is arranged outside an inner cavity of a reaction tower, a round pipe at the bottom of the powder bin penetrates through a round hole in the center of a ball bearing neck bush of the magnetic controller, the magnetic controller comprises a plurality of sector-ring-shaped permanent magnets, the permanent magnets are distributed on a supporting disc in an annular array mode, and the intervals between every two adjacent permanent magnets are the same. After a plurality of iron particles with the particle size of 1-3mm are added at one time, the speed reducing motor drives the permanent magnet to rotate at a constant speed, so that the iron particles suspend in the inner cavity of the tower to move circumferentially at a constant speed, the iron particles continuously collide with hematite powder with the particle size smaller than 200 meshes, the space stroke of the hematite powder in the inner cavity of the tower is prolonged by 1.0 m from the bottom surface of the permanent magnet, and the smelting temperature is 1100-1200 DEG C; the flash smelting method can be used for hematite concentrate powder flash smelting. High-strength smelting is achieved, the green hydrogen utilization rate exceeds 90%, the energy efficiency and the carbon efficiency are advanced, and a coke smelting blast furnace device which is a key management object of a national two-high project can be avoided.

Description

Technical Field

[0001] The invention relates to a magnetically controlled green hydrogen flash reduction smelting device and method for hematite under a temperature of 1100℃~1200℃, which extends the travel distance of hematite powder with a particle size finer than 200 mesh, and realizes green hydrogen flash reduction smelting and efficient utilization of green hydrogen. It is applicable to flash smelting of hematite concentrate, green hydrogen reduction smelting of hematite ore, resource utilization of iron oxide slag powder, and use in the manufacture of sponge iron. Background Technology

[0002] Blast furnace coke ironmaking remains the primary method of pig iron production globally due to its high efficiency, low energy consumption, and strong raw material adaptability. Despite its mature technology and high efficiency, it still suffers from the following major drawbacks: Traditional blast furnace ironmaking consumes a large amount of coke (approximately 600 kg coke / t pig iron), and coke production itself is energy-intensive and highly polluting. my country's blast furnace fuel ratio (coke + pulverized coal) is 50-100 kg / tHM higher than the international advanced level. Each ton of pig iron produced by a blast furnace generates approximately 1.8 tons of CO2, accounting for over 70% of the total emissions from the steel industry; carbon capture is costly and not widely adopted. Blast furnaces require high-grade iron ore, have poor adaptability to low-grade ores, and require sintering pretreatment, increasing costs. For the reasons mentioned above, the coke-fired blast furnaces and non-blast furnace ironmaking units (excluding hydrogen reduction) in the ironmaking (3110) industry have been included in the key management scope of the national "two high" projects (2025 edition). That is, for new and expanded ironmaking projects, the government will strictly approve the investment and construction of blast furnaces and non-blast furnace ironmaking units (excluding hydrogen reduction), requiring that the new and expanded ironmaking units be hydrogen reduction ironmaking units with high efficiency, energy saving, low carbon and environmental protection advantages. Traditional blast furnaces and non-blast furnace ironmaking units (excluding hydrogen reduction) even face the risk of being eliminated.

[0003] The high temperatures of coke-fired ironmaking, ranging from 1400℃ to 1450℃, lead to numerous problems, including increased requirements for the temperature resistance of the equipment, higher smelting furnace costs, lower thermal efficiency, and increased energy consumption. While ironmaking at 1400℃ to 1450℃ can accelerate the reduction rate, the molten surface of the pellets significantly increases thermal resistance, hindering the transfer of heat and reducing gases from the outer shell to the center. This results in excessive heat concentration on the surface layer, preventing some of the ore core from contacting the reducing agent and reaching the low temperature, thus hindering reduction. This reduces the smelting intensity and efficiency within the blast furnace cavity, increasing coke consumption and greenhouse gas emissions.

[0004] After crushing and grinding the raw ore, gangue minerals (such as quartz and silicates) are separated, and then iron concentrate powder is produced through dehydration and drying. Iron concentrate powder with Fe2O3 as its main component is hematite powder, which is not easily magnetized. Green hydrogen is used to directly reduce and smelt hematite concentrate powder and produce sponge iron powder, with no CO2 emissions throughout the entire process. Hydrogen produced by electrolyzing water using new energy sources such as solar photovoltaic and wind power is called green hydrogen. In the metallurgical industry, green hydrogen can replace the traditional fuel reducing agent CO, thus avoiding greenhouse gas emissions. Sponge iron, as a porous iron product produced by direct reduction, has become an indispensable functional material in modern metallurgical industry and water treatment field due to its pure chemical composition, unique physical structure, and diverse forms, with large industrial demand. In electric arc furnace steelmaking, it is an ideal substitute for high-quality scrap steel; in powder metallurgy, it is a high-quality raw material for high-purity iron powder; and in water treatment systems, it is a highly efficient and economical deoxygenating filter material. The research and development of a magnetically controlled green hydrogen flash reduction smelting device for hematite powder with a particle size finer than 200 mesh, which extends the travel distance and enables green hydrogen flash reduction smelting, efficient utilization of green hydrogen, and manufacturing of sponge iron products at 1100℃~1200℃, can avoid the use of traditional coke reduction blast furnaces (blast furnaces and non-blast furnace devices). Summary of the Invention

[0005] To address the problems of traditional coke ironmaking, which involves temperatures as high as 1400℃~1450℃, significant corrosion of the furnace lining during smelting and slag formation, high investment and maintenance costs for equipment (including blast furnaces and non-blast furnaces), and greenhouse gas emissions, this invention designs a magnetically controlled green hydrogen flash reduction smelting device for hematite under 1100℃~1200℃ conditions. This device extends the travel distance of hematite powder with a particle size finer than 200 mesh, enabling green hydrogen flash reduction smelting and efficient utilization of green hydrogen.

[0006] The magnetically controlled green hydrogen flash reduction smelting device for hematite mainly includes a geared motor, a magnetic controller, a dispersion cone, a green hydrogen injection pipe, a powder silo, and a reaction tower. The reaction tower is an inverted cylindrical shape with a central orifice on the top surface of its inner cavity. This central orifice allows the vertically arranged bottom circular pipe of the powder silo to pass through. The outlet of the bottom circular pipe of the powder silo is the powder outlet. The horizontally arranged top plate of the powder silo has a powder inlet, an oxygen inlet, and a central orifice. The central orifice allows the top of the green hydrogen injection pipe to pass through. The powder silo is vertically arranged outside the inner cavity of the tower. The hydrogen injection pipe passes through the inner cavity of the powder silo. The annular channel between the green hydrogen injection pipe and the bottom circular pipe of the powder silo serves as the air-powder ejection channel. A slender cylindrical upper part of the dispersion cone is arranged inside the green hydrogen injection pipe. The top of the upper cylindrical part of the dispersion cone extends beyond the green hydrogen injection pipe and is welded and fixed to the workshop crossbeam to support the entire weight of the dispersion cone. The lower truncated cone of the dispersion cone is vertically arranged inside the tower cavity, with its smaller base above its larger base. The smaller base of the lower truncated cone, the outlet surface of the green hydrogen injection pipe, and the outlet surface of the powder silo are all located within the dispersion cone. The top surface of the tower's inner cavity is coplanar. The bottom circular tube of the powder silo passes through the central tube hole of the magnetic controller. The magnetic controller mainly consists of numerous fan-shaped annular permanent magnets of equal thickness and a support disk. Gears are set on the edge of the support disk, and a ball bearing is located at the center. The circular hole of the ball bearing's inner bushing is the central tube hole of the magnetic controller. The ball bearing's inner bushing is fixed to the outer wall of the bottom circular tube of the powder silo. The gears mesh with the gears of the geared motor's main shaft. The support disk has numerous grooves of equal height evenly distributed in a circular array with the center of the ball bearing's inner bushing as the center. The height of the grooves is equal to the thickness of the permanent magnets. Permanent magnets are placed in the groove. The upper and lower surfaces of the permanent magnets are parallel, and the upper and lower surfaces are coplanar. The upper surface of the permanent magnet is perpendicular to the central axis of the ball bearing inner bushing. The inner and outer arc edges of the permanent magnets are concentric circles. Numerous permanent magnets are evenly distributed in a ring array with the center of the ball bearing inner bushing as the center. The interval between adjacent permanent magnets is the same. The central axes of the ball bearing, powder silo, green hydrogen injection pipe, dispersion cone, and tower inner cavity are collinear.

[0007] When using a magnetically controlled green hydrogen flash reduction smelting device for hematite, the smelting reducing agent and fuel are green hydrogen, and the oxidant introduced into the powder silo is oxygen at 0.4MPa (gauge pressure) to 0.6MPa (gauge pressure). The ore powder falling into the powder silo is hematite powder with a particle size finer than 200 mesh. Before the ore powder is injected into the inner cavity of the tower, numerous iron particles with a particle size of 1.0mm to 3.0mm are added at once. The permanent magnet is driven by a geared motor to rotate at a uniform speed horizontally around the central axis of the circular tube at the bottom of the powder silo, so that the iron particles are suspended in the inner cavity of the tower and move in a uniform horizontal circular motion. The iron particles continuously and elastically collide with the ore powder, prolonging the travel and residence time of the ore powder in the inner cavity of the tower within a distance of no more than 1.0m (h≤1.0m) from the bottom surface of the permanent magnet. The temperature in the inner cavity of the tower is controlled within the range of 1100℃ to 1200℃.

[0008] This invention can be used in flash smelting of magnetite concentrate, hydrogen reduction smelting of hematite ore, resource utilization of iron oxide slag powder, and manufacturing of sponge iron.

[0009] This invention is applicable to the smelting of hematite powder. The process, equipment, and supporting facilities are simple, with low unit investment. The smelting temperature is reduced from 1400℃~1450℃ to 1100℃~1200℃. The equipment is compact, with extremely fast smelting speed (flash smelting) and high smelting intensity (high utilization rate of tower internal space). The green hydrogen utilization rate exceeds 90%. There is no corrosion of the equipment lining caused by molten slag smelting. The equipment produces advanced energy efficiency and carbon efficiency indicators, and the sponge iron products have uniform quality. It avoids the production of pig iron for steelmaking, molten reduced iron, and pig iron for casting, which are key targets of national "two high" projects, as well as blast furnace and non-blast furnace ironmaking equipment for coke smelting. Attached Figure Description

[0010] Figure 1 A vertical sectional view of a magnetically controlled green hydrogen flash reduction smelting unit for hematite. Figure 2 This is a horizontal sectional view of magnetron 2. Figure 1 In the diagram, 1 is a geared motor, 2 is a magnetic controller, 21 is a permanent magnet, 22 is a support plate, 3 is a dispersion cone, 4 is a green hydrogen injection pipe, 5 is a powder silo, 51 is a powder drop inlet, 52 is an oxygen inlet, and 6 is a reaction tower. Figure 2 In the diagram, 21 is a permanent magnet, 22 is a support disk, 221 is a gear, and 222 is a ball bearing. Detailed Implementation

[0011] The invention will now be further described with reference to the accompanying drawings.

[0012] like Figure 1As shown, the magnetically controlled green hydrogen flash reduction smelting device for hematite mainly includes a geared motor 1, a magnetic controller 2, a dispersion cone 3, a green hydrogen injection pipe 4, a powder silo 5, and a reaction tower 6. The reaction tower 6 is an inverted cylindrical shape with a central bore on the top surface of its inner cavity, through which the vertically arranged bottom circular pipe of the powder silo 5 passes. The powder silo 5 includes a vertically arranged bottom circular pipe and a horizontally arranged top plate. The outlet of the bottom circular pipe is the outlet of the powder silo 5. The top plate has a powder inlet 51, an oxygen inlet 52, and a central bore, through which the top of the green hydrogen injection pipe 4 passes. The powder silo 5 is vertically arranged outside the inner cavity of the tower. The green hydrogen injection pipe 4 passes through the inner cavity of the powder silo 5. The annular channel between the green hydrogen injection pipe 4 and the bottom circular pipe of the powder silo 5 is the air-powder ejection channel. The upper part of the dispersion cone 3 is arranged in the inner cavity of the green hydrogen injection pipe 4. The dispersion cone 3 comprises a vertically arranged upper cylinder and a vertically arranged lower truncated cone. The top of the upper cylinder extends beyond the green hydrogen injection pipe 4 and is welded and fixed to the workshop crossbeam to support the entire weight of the dispersion cone 3. The lower truncated cone is arranged inside the tower cavity, with its smaller base surface above the larger base surface. The smaller base surface of the lower truncated cone 3, the outlet surface of the green hydrogen injection pipe 4, the outlet surface of the powder silo 5, and the top surface of the tower cavity are coplanar. The bottom circular tube of the powder silo 5 passes through the central tube hole of the magnetron 2. The magnetic controller 2 mainly includes numerous fan-shaped annular permanent magnets 21 of equal thickness and a support disk 22. Gears 221 are arranged at the edges of the support disk 22, and a ball bearing 222 is located at its center. The inner bushing of the ball bearing 222 has a circular hole that serves as the central tube hole of the magnetic controller 2. The inner bushing of the ball bearing 222 is fixed to the outer wall of the bottom circular tube of the powder silo 5. The gears 221 mesh with the main shaft gear of the reduction motor 1. The support disk 22 has numerous grooves of equal height evenly distributed in a circular array centered on the inner bushing of the ball bearing 222. The height of the grooves is equal to the thickness of the permanent magnets. The magnets 21 are of equal thickness and are placed in the grooves. The upper and lower surfaces of the permanent magnets 21 are parallel, and both the upper and lower surfaces are coplanar. The upper surface of the permanent magnets 21 is perpendicular to the central axis of the inner bushing of the ball bearing 222. The inner and outer arc edges of the permanent magnets 21 are concentric circles. Numerous permanent magnets 21 are evenly distributed in a ring array with the center of the inner bushing of the ball bearing 222 as the center. The spacing between adjacent permanent magnets 21 is the same. The central axes of the ball bearing 222, powder hopper 5, green hydrogen injection pipe 4, dispersion cone 3, and tower inner cavity are collinear.

[0013] The geared motor 1 includes a main shaft gear, which is vertically arranged and meshes with the outer edge gear of the support plate 22 of the magnetic controller 2. The magnetic controller 2 rotates uniformly around the central axis of the bottom circular tube of the powder silo 5. Changing the speed of the geared motor 1 can change the speed of the magnetic controller 2. The geared motor 1 can be arranged above or below the magnetic controller 2.

[0014] The magnetic controller 2 includes numerous permanent magnets 21 and a support disk 22. All permanent magnets 21 are fan-shaped and of equal thickness. Gears 221 are located at the edge of the support disk 22, and a ball bearing 222 is located at its center. The inner wall of the inner bushing of the ball bearing 222 is in close contact with and fixedly connected to the outer wall of the bottom circular tube of the powder silo 5, ensuring that the bottom circular tube of the powder silo 5 remains stationary. Driven by the geared motor 1, the magnetic controller 2 can rotate at a constant speed around the central axis of the bottom circular tube of the powder silo 5. The edge gears 221 mesh with the main shaft gear of the geared motor 1. The support disk 22 has numerous grooves arranged in a circular array, with the center of the inner bushing of the ball bearing 222 as the center. The grooves are evenly distributed in a circular array, and their height is equal to the thickness of the permanent magnets 21. The permanent magnets 21 are placed within the grooves. The upper and lower surfaces of the numerous permanent magnets 21 are parallel. The upper and lower surfaces of numerous permanent magnets 21 are coplanar. The upper surface of the permanent magnets 21 is perpendicular to the central axis of the bottom circular tube of the powder silo 5. The inner and outer arc edges of the permanent magnets 21 are concentric circles. The numerous permanent magnets 21 are evenly distributed in a ring array with the center of the inner bushing of the ball bearing 222 as the center. When the magnetic controller 2 rotates around the central axis of the bottom circular tube of the powder silo 5, the permanent magnets 21 placed in the groove of the support plate 22 also rotate uniformly around the central axis of the bottom circular tube of the powder silo 5 at the same speed.

[0015] The dispersion cone 3 comprises a vertically arranged upper cylinder and an upright lower truncated cone. The bottom surface of the upper cylinder and the small bottom surface of the lower truncated cone have the same diameter and are fully welded together. The upper cylinder is fitted inside the green hydrogen injection pipe 4. The central axes of the upper cylinder and the green hydrogen injection pipe 4 are collinear. The top of the upper cylinder passes through the green hydrogen injection pipe 4 and is welded to the workshop crossbeam to support the entire weight of the dispersion cone 3. The top of the dispersion cone 3 is welded and fixed to the workshop crossbeam, while the lower truncated cone is freely suspended in the inner cavity of the tower. The small bottom surface of the lower truncated cone is on top, and the large bottom surface is on the bottom. The small bottom surface of the truncated cone is coplanar with the top surface of the inner cavity of the tower. The truncated cone is arranged in the inner cavity of the tower. The small bottom surface of the lower truncated cone, the outlet surface of the powder silo 5, and the top surface of the inner cavity of the tower are coplanar. The central axes of the dispersion cone 3, the green hydrogen injection pipe 4, and the inner cavity of the tower are collinear.

[0016] The green hydrogen injection pipe 4 is a straight pipe. The upper cylinder of the dispersion cone 3 is arranged inside the green hydrogen injection pipe 4, which is located inside the powder silo 5. The top end of the green hydrogen injection pipe 4 passes through the central hole in the top plate of the powder silo 5, and the bottom end passes through the inner cavity of the bottom circular pipe of the powder silo 5. The outlet surface of the green hydrogen injection pipe 4 is coplanar with the top surface of the tower cavity. The central axes of the green hydrogen injection pipe 4, the powder silo 5, and the reaction tower 6 are collinear.

[0017] The powder silo 5 includes an inverted conical barrel at the top and a vertically arranged circular tube at the bottom. The large base plate of the top conical barrel is on top, and the small bottom opening is at the bottom. The circumference of the small bottom opening and the circumference of the bottom circular tube inlet are fully welded together. The bottom circular tube passes through the central tube hole on the top surface of the inner cavity of the tower, and the outlet surface of the bottom circular tube is coplanar with the top surface of the inner cavity of the tower. The large base plate of the top conical barrel is provided with a powder inlet 51, an oxygen inlet 52, and a central tube hole, through which the top end of the green hydrogen injection pipe 4 passes. The green hydrogen injection pipe 4 vertically passes through the inner cavity of the powder silo 5. The powder silo 5 is located above the top wall of the reaction tower 6, and the central axis of the powder silo 5 and the reaction tower are collinear.

[0018] The reaction tower 6 is shaped like an inverted cylinder, with its inner cavity used for thorough dispersion of the powder and the green hydrogen reduction smelting reaction. A central tube hole is opened on the top surface of the inner cavity, through which the bottom circular tube of the powder silo 5 passes. The outlet surface of the bottom circular tube of the powder silo 5 is coplanar with the top surface of the inner cavity. The top conical cylinder and bottom circular tube of the powder silo 5, the green hydrogen injection pipe 4, the upper cylinder and lower frustum-shaped cone of the dispersion cone 3 are collinear with the centerline of the reaction tower 6.

[0019] The bottom circular tube of powder silo 5 passes through the central hole on the top surface of the tower cavity. The outlet surface of the bottom circular tube is coplanar with the top surface of the tower cavity, and powder silo 5 is located above the top surface of the tower cavity. The top end of the green hydrogen injection pipe 4 passes through the central hole on the top plate of powder silo 5, and the bottom end passes through the inner cavity of the bottom circular tube of powder silo 5. The outlet surface of the green hydrogen injection pipe 4 is coplanar with the top surface of the tower cavity. The upper cylinder of dispersion cone 3 is fitted inside the inner cavity of green hydrogen injection pipe 4. The central axes of the upper cylinder of dispersion cone 3, green hydrogen injection pipe 4, and powder silo 5 are collinear. The bottom end face of the upper cylinder of dispersion cone 3 is fully welded to the small bottom surface of the lower truncated cone. The bottom end face of the upper cylinder, the small bottom surface of the lower truncated cone, and the top surface of the tower cavity are coplanar. The lower truncated cone is located inside the tower cavity. The bottom circular tube of powder silo 5 passes through the inner sleeve of ball bearing 222, which is fixedly connected to the bottom circular tube of powder silo 5. A permanent magnet 21 is placed in the groove of support disk 22. The edge gear 221 of support disk 22 meshes with the main shaft gear of reduction motor 1. Support disk 22 is perpendicular to the central axis of the bottom circular tube of powder silo 5. The central axes of the inner sleeve of ball bearing 222, powder silo 5, green hydrogen injection pipe 4, dispersion cone 3, and reaction tower 6 are collinear.

[0020] When using the magnetically controlled green hydrogen flash reduction smelting device for hematite, the smelting reducing agent fuel is green hydrogen, and the oxidant introduced into the powder silo 5 is oxygen at 0.4MPa (gauge pressure) to 0.6MPa (gauge pressure). The ore powder falling into the powder silo 5 is hematite powder with a particle size finer than 200 mesh. Before the ore powder is injected into the inner cavity of the tower, a large number of iron particles with a particle size of 1.0mm to 3.0mm are added at once. The permanent magnet 21 is driven by the geared motor 1 to rotate at a uniform speed horizontally around the central axis of the bottom circular tube of the powder silo 5, so that the iron particles are suspended in the inner cavity of the tower and move at a uniform speed horizontally. The iron particles continuously make elastic collisions with the ore powder, which prolongs the travel and residence time of the ore powder in the inner cavity of the tower within a distance of no more than 1.0m (h≤1.0m) from the bottom surface of the permanent magnet 21. The temperature of the inner cavity of the tower is controlled in the range of 1100℃ to 1200℃.

[0021] Driven by the geared motor 1, the magnetic controller 2 rotates slowly and uniformly, causing numerous permanent magnets 21 to rotate horizontally around the central axis of the powder silo 5. Within the tower cavity space, which is no more than 1.0m (h≤1.0m) vertically from the bottom of the permanent magnet 21, the iron particles pre-added to the tower cavity are magnetized and then subjected to an upward oblique magnetic force from the permanent magnets 21. The permanent magnets 21 are fan-shaped, forming a circular area. Adjacent permanent magnets 21 have the same spacing, so that during the rotation of the magnetic controller 2, the two permanent magnets 21 in front and behind apply a stable upward oblique magnetic force to the same iron particle. The circular rotation of the permanent magnets 21 around the central axis of the powder silo 5 applies a stable tangential magnetic force to the iron particle, and at the same time applies a stable upward vertical magnetic force to overcome its own gravity. Finally, the iron particle is suspended in the tower cavity and moves in a uniform horizontal circular motion along the central axis of the tower cavity.

[0022] After passing through the material seal at the inlet of powder silo 5, the ore powder falls into powder silo 5 through powder drop inlet 51, and mixes evenly with 0.4MPa (gauge pressure) to 0.6MPa (gauge pressure) oxygen introduced from oxygen inlet 52 to form an airflow (0.4MPa (gauge pressure) to powder (iron ore powder)). At the outlet of powder silo 5, the airflow mixes with the green hydrogen injected from green hydrogen injection pipe 4 to form a mixed airflow of "oxygen + green hydrogen + ore powder". The mixed airflow is injected into the inner cavity of the tower at a certain speed through the annular channel between the bottom circular pipe of powder silo 5 and green hydrogen injection pipe 4. After the mixed airflow of "oxygen + green hydrogen + ore powder" leaves the outlet of the bottom circular pipe of powder silo 5, it first touches the side wall of the lower truncated cone of dispersion cone 3. Under the guiding action of the side wall of the lower truncated cone of dispersion cone 3, the direction of movement of ore powder changes, decomposing into radial velocity component and decreasing vertical velocity component. The ore powder is moved to an area outside the center of the inner cavity of the tower and moves downwards in a projectile motion. After leaving the side wall of the truncated cone at the bottom of the dispersion cone 3, the mixed gas flow of "oxygen + green hydrogen + mineral powder" is ignited and undergoes pure oxygen combustion of green hydrogen. There is an excess of green hydrogen, and the oxygen is completely consumed. The mineral powder and excess green hydrogen absorb part of the heat released by the combustion of pure oxygen and green hydrogen, raising the temperature to 1100℃~1200℃, and becoming a gas flow of "water vapor + green hydrogen + mineral powder" at 1100℃~1200℃. The remaining heat released by the combustion of pure oxygen and green hydrogen is absorbed by the reduction smelting reaction of the remaining green hydrogen. The heat released by the combustion of pure oxygen and green hydrogen = the heat absorbed by the heating of hematite powder and green hydrogen to 1100℃~1200℃ + the heat absorbed by the flash reduction smelting reaction of the remaining green hydrogen, thus establishing the high-temperature environment of 1100℃~1200℃ required for the complete reduction smelting reaction of green hydrogen. Within the tower cavity space, within a vertical distance of no more than 1.0m (h≤1.0m) below the bottom surface of permanent magnet 21, ore powder particles at 1100℃~1200℃ in the green hydrogen reduction smelting gas flow continuously encounter iron particles with a diameter of 1.0mm~3.0mm undergoing stable, uniform circular motion. Elastic collisions occur, resulting in the decomposition of tangential velocity components. Both radial and vertical velocities decrease, and the motion of the ore powder particles changes from simple projectile motion to spiral downward motion. The travel distance and residence time of the ore powder within the tower cavity space within 1.0m (h≤1.0m) below the bottom surface of permanent magnet 21 are extended. The radial and vertical scraping of green hydrogen by the ore powder becomes radial, vertical, and tangential scraping, with the tangential scraping becoming the dominant scraping action, creating the time conditions required for the complete reduction smelting reaction of green hydrogen. The ore powder particle size is finer than 200 mesh, and the ore powder flows with the mixed gas flow in the "oxygen + green hydrogen + ore powder" gas flow, without any air-powder separation. The bottom of the dispersion cone 3 is set with a frustum-shaped cone to prevent the mineral powder particles from being excessively concentrated in the central axis area of ​​the tower cavity, and to disperse them in the area outside the center of the tower.

[0023] Within the tower space no more than 1.0m (h≤1.0m) below the bottom surface of permanent magnet 21, the tangential scraping effect of the mineral powder particles is adjustable and controllable. The faster the rotation speed of the magnetron 2, the greater the number of iron particles, and the wider the particle size distribution, the smaller the pitch of the spiral motion trajectory of the mineral powder particles, the longer the spatial travel and residence time of the mineral powder particles, and the stronger the tangential scraping effect of the mineral powder particles. After a limited number of experiments, the optimal combination of the rotation speed of the magnetron 2 and the number and size distribution of iron particles can be obtained, so that when the mineral powder leaves the tower cavity space no more than 1.0m (h≤1.0m) below the bottom surface of permanent magnet 21, the green hydrogen reduction smelting reaction is just completely completed, forming green hydrogen high-intensity flash reduction smelting of hematite powder. The oxygen flow rate is optimized, and the temperature of the tower cavity space within 1.0m (h≤1.0m) below the bottom surface of permanent magnet 21 is controlled within the range of 1100℃~1200℃. Iron particles with a particle size of 1.0mm~3.0mm, hematite concentrate powder with a particle size of less than 200 mesh, and sponge iron powder with a particle size of less than 200 mesh are all in a solid state. Iron particles with a particle size of 1.0mm~3.0mm can be magnetized, hematite concentrate powder with a particle size of less than 200 mesh is not magnetized, and sponge iron powder with a particle size of less than 200 mesh is not magnetized because the vertical distance from the bottom surface of permanent magnet 21 exceeds 1.0m (h>1.0m).

[0024] The permanent magnet 21 of the magnetic controller 2 first maintains a uniform rotation speed. Then, numerous iron particles with a diameter of 1.0mm to 3.0mm are added to the powder hopper 5. The iron particles fall into the inner cavity of the tower through the annular mineral powder ejection channel at the bottom of the powder hopper 5. Under the guiding effect of the side wall of the truncated cone at the bottom of the dispersion cone 3, the iron particles enter the area outside the center of the inner cavity of the tower. Under the action of the permanent magnet 21 located above the top wall of the reaction tower 6, the iron particles are first magnetized, and then move in uniform circular motion under the attraction of tangential magnetic force. The vertical upward magnetic force and the vertical downward gravity on the iron particles are equal. The iron particles are suspended in the inner cavity space of the tower no more than 1.0m below the bottom surface of the permanent magnet 21 (h≤1.0m). Moreover, different particle sizes are suspended at different heights in the inner cavity of the tower (large iron particles are at the top and closer to the center, and small iron particles are at the bottom and farther from the center), so that the mineral powder will undergo elastic collision and displacement every time it falls a certain height. The iron particles, with a diameter of 1.0mm to 3.0mm, are much coarser than the 200-mesh ore powder. The ore powder injected into the tower cavity has minimal impact on the iron particles, which remain suspended within the tower cavity without falling. The uniform circular motion of the iron particles is unaffected. The temperature inside the tower cavity is controlled within the range of 1100℃ to 1200℃. The iron particles pre-added to the tower cavity do not melt and remain in a solid particle state. The magnetic force exerted by the permanent magnet 21 on the numerous iron particles does not diminish.

[0025] When using the magnetically controlled green hydrogen flash reduction smelting hematite device, iron particles with a diameter of 1.0mm to 3.0mm are added only once. If the permanent magnet 21 does not stop its circular motion, there is no need to add iron particles again. The ore powder can be continuously or intermittently sprayed into the inner cavity of the tower.

[0026] The mineral powder falls into the powder silo 5 through the mineral powder inlet 51, and is then sprayed into the inner cavity of the tower through the annular channel at the bottom of the powder silo 5. Under the guiding effect of the side wall of the truncated cone at the bottom of the dispersion cone 3, the mineral powder is dispersed and distributed in the area outside the center of the inner cavity of the tower. In the inner cavity space of the tower, which is no more than 1.0m (h≤1.0m) below the bottom surface of the permanent magnet 21, the mineral powder falls horizontally, and during this process, it continuously undergoes elastic collisions with the uniformly moving iron particles. The mineral powder particles continuously shift along the circumference. The horizontal falling of the mineral powder is superimposed with the circumferential motion, and finally falls spirally. When the mineral powder leaves the inner cavity space of the tower, which is no more than 1.0m (h≤1.0m) below the bottom surface of the permanent magnet 21, the hematite concentrate powder, which is as fine as 200 mesh and has a temperature of 1100℃~1200℃, is flash-reduced. The hematite concentrate powder is transformed into sponge iron powder, which falls into the cooling area at the bottom of the reaction tower, and finally cools down to 80℃~100℃, and is discharged from the tower by the screw conveyor.

[0027] The core of the magnetically controlled green hydrogen flash reduction smelting device for hematite involves pre-injecting numerous iron particles with a diameter of 1.0mm to 3.0mm. A geared motor 1 rotates, driving a magnetic controller 2 to rotate, magnetizing the iron particles and suspending them within the tower cavity. These particles then move in a uniform horizontal circular motion within the tower cavity, applying a tangential force to the iron powder particles. This extends the travel distance of the iron powder within the tower cavity, no more than 1.0m below the bottom surface of the permanent magnet 21 (h≤1.0m), thus prolonging the green hydrogen reduction smelting reaction time. After the iron powder is injected into the tower cavity, it continuously undergoes elastic collisions with the uniformly moving 1.0mm to 3.0mm iron particles, causing the iron powder to shift along its circumference, extending its travel distance and residence time. These elastic collisions do not result in kinetic energy loss, and the tangential velocity component in the iron powder's motion inevitably reduces its projectile motion speed. This prolongs the contact time between the iron powder and the green hydrogen, ensuring a more complete green hydrogen reduction smelting reaction and improving the purity of the sponge iron powder. Because the temperature inside the tower is controlled within the range of 1100℃ to 1200℃, the iron particles do not melt, and the magnetic force on the iron particles does not diminish. The iron particles maintain a uniform circular motion with the magnetic controller 2. The magnetic controller 2 is installed on the top wall of the reaction tower 6, which changes the movement of the mineral powder from the original orderly horizontal drop to a spiral drop, prolonging the movement and residence time of the mineral particles inside the tower, enhancing the mixing of mineral powder and green hydrogen, and improving the effective utilization rate of the space inside the reaction tower.

[0028] The greater the amount of ore per unit volume within the tower cavity, the more uniform the ore distribution, the longer the ore powder travel (longer residence time), the faster the smelting speed, the greater the smelting intensity, and the higher the smelting production efficiency. Within the tower cavity space with a vertical distance h ≤ 1.0m from the bottom surface of the permanent magnet 21, the ore powder flows in a spiral pattern. The pitch of the ore powder trajectory depends on the rotation speed of the permanent magnet 21; the faster the permanent magnet 21 rotates, the smaller the ore powder trajectory pitch. Within the tower cavity space with a vertical distance h ≤ 1.0m from the bottom surface of the permanent magnet 21, the spiral flow of the ore powder can increase the travel of the ore powder in the 1100℃~1200℃ region and prolong the residence time of the ore powder, improve the filling degree of the ore powder space, increase the uniformity of the ore powder spatial distribution, thereby improving the utilization rate of the tower cavity space, reducing the tower cavity volume and reducing the investment per unit capacity, and helping to improve the uniformity of powder-oxygen mixing, thus improving the thermodynamic conditions of the subsequent green hydrogen flash reduction smelting reaction. Green hydrogen molecules have strong diffusion ability and strong penetration into capillaries. The hematite concentrate powder injected into the tower cavity has a particle size finer than 200 mesh. On the one hand, this expands the surface area of ​​the powder, reducing the resistance to the lateral diffusion of green hydrogen into the powder group; on the other hand, it reduces the resistance to the penetration of green hydrogen into the microscopic capillaries of the powder particles, increasing the possibility of a complete green hydrogen reduction smelting reaction. The magnetron 2 rotates slowly and uniformly, attracting iron particles to move in a uniform horizontal circular motion within the tower cavity space, no more than 1.0m (h≤1.0m) vertically from the bottom surface of the permanent magnet 21. This continuous elastic collision with the powder optimizes the powder's downward motion from a horizontal projectile motion to a spiral downward motion, extending the travel and residence time of the high-temperature powder in the green hydrogen environment, creating thermodynamic conditions for a complete green hydrogen reduction smelting reaction. Applications show that achieving green hydrogen flash reduction smelting of hematite powder increases the primary utilization rate of green hydrogen from 15%–30% in hydrogen reduction smelting of sinter to over 90%, solving problems such as low primary hydrogen utilization and low smelting efficiency in green hydrogen reduction smelting of pellets / sinter.

[0029] Before falling into the powder silo 5, the mineral powder passes through a material seal to prevent ambient air from entering the tower cavity, thus avoiding impurities such as nitrogen from affecting the green hydrogen reduction reaction rate inside the tower. This ensures that the reduction reaction waste gas is mainly composed of water vapor and hydrogen, improving the economic efficiency of condensing and recovering the latent heat and residual hydrogen (<10%) of water vapor in the reduction reaction waste gas outside the reaction tower 6. The oxygen introduced into the powder silo 5 has a certain pressure, which can improve the flowability of the mineral powder within the powder silo 5 and prevent the formation of material arches at the bottom circular pipe inlet of the powder silo 5 due to the reduced cross-sectional area, which could prevent the mineral powder from being ejected. The permanent magnet 21 is made of permanent magnet material, the support plate 22 is made of non-magnetic material, and the powder silo 5, green hydrogen injection pipe 4, and dispersion cone 3 are all made of magnetically resistive materials. After the magnetic resistance effect of the "magnetic permeable layer-insulation layer-fire resistant layer" on the top wall of reaction tower 6, the magnetic force of permanent magnet 21 on the iron particles in the tower cavity is weakened. The experiment shows that within the tower cavity space where the vertical distance from the bottom surface of permanent magnet 21 does not exceed 1.0m (h≤1.0m), the magnetic force of permanent magnet 21 on iron particles always exists.

[0030] The beneficial effects of using a magnetically controlled green hydrogen flash reduction smelting device for hematite powder include at least the following:

[0031] (1) Direct production of solid powder sponge iron without melting and slag smelting reduces the requirements for high temperature and corrosion resistance of the equipment lining, extends service life, and reduces investment.

[0032] (2) The green hydrogen flash reduction smelting short-process steelmaking process replaces the sintering-blast furnace melting and slag-forming long-process steelmaking process. The raw material is changed from pellets / sinter to hematite powder finer than 200 mesh, avoiding the sintering unit and simplifying the ironmaking process. Dynamic green hydrogen flash reduction smelting of iron ore powder replaces static CO reduction smelting of pellets / lumps of sinter, which speeds up the smelting speed, shortens the smelting time, improves the smelting intensity per unit volume and the utilization rate of the tower cavity space, makes the smelting reaction more thorough, improves the smelting efficiency, and achieves a green hydrogen utilization rate of over 90%.

[0033] (3) Sponge iron replaces pig iron for steelmaking, molten reduced iron and pig iron for casting, which are key targets of the national "two high" projects. Hydrogen reduction ironmaking furnaces replace blast furnaces, which is in line with the requirements of national industrial policies.

[0034] (4) The smelting temperature is reduced from 1400℃~1450℃ to 1100℃~1200℃, the mineral powder particles remain in an unmelted solid particle state, the microscopic capillaries of the powder particles are not blocked, and the good porous properties of sponge iron are maintained.

[0035] (5) The energy consumed is green electricity and green hydrogen, without consuming coke or emitting greenhouse gases, achieving true "zero" carbon smelting, and the carbon efficiency index of the equipment products is advanced.

[0036] (6) Green hydrogen reduction smelting flue gas purification replaces desulfurization and denitrification purification with water removal purification, and flue gas waste heat recovery mainly recovers the latent heat of condensation of flue gas water vapor. The energy utilization rate of the unit is significantly improved and the energy efficiency indicators of the unit's products are advanced.

Claims

1. A device for smelting hematite by magnetron green hydrogen flash reduction, mainly comprising a speed reducer, a magnetic control device, a dispersion cone, a green hydrogen injection pipe, a powder bin and a reaction tower, the reaction tower is in the shape of an inverted barrel, a central pipe hole is formed in the top surface of the inner cavity of the tower, the bottom circular pipe of the powder bin is vertically arranged through the central pipe hole, the outlet of the bottom circular pipe of the powder bin is the outlet of the powder bin, the top plate of the powder bin is horizontally arranged, a powder falling inlet, an oxygen inlet and a central pipe hole are formed in the top plate, the top end of the green hydrogen injection pipe is arranged through the central pipe hole, the powder bin is vertically arranged outside the inner cavity of the tower, the green hydrogen injection pipe is arranged through the inner cavity of the powder bin, the annular channel between the green hydrogen injection pipe and the bottom circular pipe of the powder bin is a wind-powder injection channel, an elongated cylindrical body is arranged in the upper part of the dispersion cone in the inner cavity of the green hydrogen injection pipe, the top end of the upper cylindrical body of the dispersion cone extends out of the green hydrogen injection pipe, and is welded and fixed on the workshop cross beam to support the whole weight of the dispersion cone, the lower conical table body of the dispersion cone is vertically arranged in the inner cavity of the tower, is vertically arranged, and the small bottom surface is above the large bottom surface, the small bottom surface of the lower conical table body of the dispersion cone, the outlet surface of the green hydrogen injection pipe, the outlet surface of the powder bin and the top surface of the inner cavity of the tower are coplanar, and the device is characterized in that: The bottom circular tube of the powder bin passes through the central tube hole of the magnetic controller. The magnetic controller mainly comprises a plurality of annular equal-thickness permanent magnets and a support disc. The support disc is provided with gears at the edge and a ball bearing at the center. The ball bearing inner sleeve circular hole is the central tube hole of the magnetic controller. The ball bearing inner sleeve is fixed on the outer wall surface of the bottom circular tube of the powder bin. The gears are engaged with the main shaft gears of the speed reducer motor. The support disc is provided with a plurality of equal-height grooves evenly distributed in an annular array with the ball bearing inner sleeve center as the circle center. The groove height is equal to the thickness of the permanent magnet. The permanent magnet is placed in the groove. The upper surface and the lower surface of the permanent magnet are parallel. The upper surfaces of the permanent magnets are coplanar, the lower surfaces of the permanent magnets are coplanar, and the upper surface of the permanent magnet is perpendicular to the central axis of the ball bearing inner sleeve. The inner arc edge of the permanent magnet is concentric with the outer arc edge. The circle where the inner arc edge of the permanent magnet is located and the circle where the outer arc edge of the permanent magnet is located are concentric circles. A plurality of permanent magnets are evenly distributed in an annular array with the ball bearing inner sleeve center as the circle center. The interval between the two adjacent permanent magnets is the same. The ball bearing, the powder bin, the green hydrogen injection pipe, the dispersion cone and the central axis of the tower cavity are collinear.

2. When using the magnetic green hydrogen flash reduction smelting hematite device of claim 1, the smelting reducing agent and fuel are green hydrogen, the oxidizing agent introduced into the powder bin is 0.4 MPa (gauge pressure) to 0.6 MPa (gauge pressure) oxygen, the falling powder in the powder bin is hematite powder with a particle size finer than 200 mesh, a plurality of iron particles with a particle size of 1.0 mm to 3.0 mm are added into the tower cavity before the injection of the powder, the permanent magnet is driven by the speed reducer to rotate around the central axis of the bottom circular tube of the powder bin at a uniform speed, so that the iron particles are suspended in the tower cavity and move in a uniform circular motion. The iron particles continuously and elastically collide with the powder, prolonging the travel and residence time of the powder in the tower cavity space within 1.0 m (h≤1.0 m) from the bottom surface of the permanent magnet. The temperature in the tower cavity is controlled in the range of 1100℃ to 1200℃.

Images