Magnetic separation device and magnetic separation method

Abstract

The invention relates to the technical field of ferrous metallurgy, in particular to a magnetic separation device and a magnetic separation method.The magnetic separation device comprises a diameter dividing device, a magnetic separation roller, a separation bin and a separation residue bin; the diameter dividing device is selected from any one of a wind screening device, a belt screening device, a chute screening device or a vibrating screen screening device; the diameter dividing device is provided with a plurality of discharging ports, each discharging port is provided with a magnetic separation roller, each magnetic separation roller comprises a magnet and a roller body, and the magnets are located on the inner sides of the roller bodies. The selection bin is located below a selection falling point of the magnetic separation roller, and the residual selection bin is located below a residual selection falling point of the magnetic separation roller. According to the magnetic separation device, the technical defects that in an existing magnetic separation device, due to the fact that the particle size difference is large, the distance difference between the mass center of particles and the surface of a magnet is large, the same-grade particles cannot obtain the same magnetic separation probability, and the magnetic separation efficiency is affected are overcome.

Description

Technical Field

[0001] This invention relates to the field of iron and steel metallurgy technology, specifically to a magnetic separation device and a magnetic separation method. Background Technology

[0002] Using gas-solid reduction to obtain sponge iron, which can be directly fed into a steelmaking furnace for steelmaking, avoids the numerous environmentally unfriendly problems associated with blast furnaces, sintering, coking, and pelletizing processes. Especially when using hydrogen to produce sponge iron, zero carbon dioxide emissions can be achieved, a generally accepted direction. However, its adoption has been slow for many years. The fundamental reason is that the core control equipment for the two currently used processes is either a vertical shaft furnace or a fluidized bed, both of which have insurmountable drawbacks. The main drawback of the vertical shaft furnace is the necessity of pelletizing, which severely limits the types of iron ore powder that can be used. The main drawback of the fluidized bed is the large heat diffusion loss during production, high power consumption of fluidized bed blasting, and, more importantly, the low iron content of the main source of coarse ore after fluidized bed reduction, which is unacceptable for steelmaking processes. Therefore, direct steelmaking is not possible; the iron must first be refined into molten iron before being sent to the steelmaking process. This process of refining sponge iron into molten iron not only increases production costs but also generates a large amount of carbon dioxide emissions. These drawbacks result in the overall cost of these two processes being significantly higher than that of the blast furnace process, making them unsuitable for the market.

[0003] How to achieve direct steelmaking from various types and low-grade iron ore powders to meet the development needs of low-carbon and zero-carbon industries has become a technical problem that needs to be solved by existing technologies. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a magnetic separation device and a magnetic separation method for diameter separation: To achieve the above-mentioned technical effects, the present invention adopts the following technical solution: This invention discloses a magnetic separator for diameter separation, comprising a diameter separation device, a magnetic separator roller, a separation bin, and a separation residue bin; The sizing device is selected from any one of the following: pneumatic screening device, belt screening device, chute screening device, or vibrating screen screening device; The sizing device is equipped with multiple discharge ports, each of which is equipped with a magnetic separation roller. The magnetic separation roller includes a magnet and a cylinder body. The magnet is located inside the cylinder body. During operation, the position of the magnet is fixed, while the cylinder body is rotating.

[0005] The separation chamber is located below the separation drop point of the magnetic separation roller, and the separation residue chamber is located below the separation residue drop point of the magnetic separation roller. Specifically, the separation drop point is located below the non-magnetic area of ​​the magnetic separation roller, and the separation residue drop point is located below the magnetic area of ​​the magnetic separation roller.

[0006] Preferably, the magnet is selected from electromagnets and / or permanent magnets, and the distance between the magnet and the cylinder is adjustable.

[0007] Specifically, the sizing device can be equipped with a transverse air nozzle, the outlet of which faces the falling particles; it can also be equipped with a gas-solid two-phase air outlet to throw out the particles; it can be equipped with a rapidly rotating belt to throw out the particles placed on the belt; or it can be equipped with a chute to throw out the particles flowing in the chute as they leave the chute. At different landing points of different particle sizes, intermediate material troughs of different particle sizes are set. The sizing device can also be a multi-layer vibrating screen, with intermediate material troughs of different particle sizes correspondingly set at the discharge port of each layer and at the bottom layer under the screen; each intermediate material trough outlet is equipped with... A magnetic separator roller contains magnets that can be electromagnets or permanent magnets. When permanent magnets are used, the magnets are divided into multiple sections along the circumference of the roller and arranged at certain intervals from the roller surface. A magnetic separation interval adjustment mechanism can be provided: each magnet has a threaded hole, similar to a nut that can only move radially and not rotate. The threaded hole is threadedly connected to one end of a screw, and the other end of the screw has a bevel gear. The screw is mounted on a bearing seat on the frame and can only rotate by the bevel gear, not radially or circumferentially. A control rod bevel gear meshes with the bevel gear on the screw. The control rod bevel gear is mounted on a control rod, which is aligned with the axis of the magnetic separator roller. The axes of each screw are radially aligned with the magnetic separator roller. At the separation dropout point of each magnetic separator roller, a separation chute is provided, connecting to a lower separation bin; at the retention dropout point, a retention chute is provided, connecting to a lower retention bin.

[0008] The magnetic force is adjusted by changing the distance between the magnet and the roller surface. The magnetic force of each magnetic separation roller in each particle size group is adjusted according to the predetermined grade of magnetic separation. Each magnetic separation roller rotates with particles, and there is a separation chute below its separation drop point and a retention chute below its retention drop point. The outlet of the separation chute of all magnetic separation rollers is connected to the separation chamber, and the outlet of the retention chute of all magnetic separation rollers is connected to the retention chamber. Strongly magnetized particles of a preset intensity will fall from the separation drop point of the magnetic separation roller into the separation chute and flow into the separation chamber. Weakly magnetized particles of a preset intensity will fall from the retention drop point of the magnetic separation roller into the retention chute and enter the retention chamber to achieve the purpose of magnetic separation.

[0009] The present invention also discloses a magnetic separation method for particle size separation, wherein the particles to be magnetically separated are sorted into different particle size groups according to their particle size, and the particles to be magnetically separated in different particle size groups are respectively magnetically separated and screened by a magnetic separation device to obtain strongly magnetized particles and weakly magnetized particles.

[0010] The diameter separation magnetic separation method can be implemented using the aforementioned diameter separation magnetic separation device, and a further embodiment of the diameter separation magnetic separation method is as follows: After passing through the sizing device, the magnetically separated particles are sorted into different particle size groups, and the different particle size groups enter different intermediate material tanks respectively; The particles to be magnetically separated discharged from different intermediate feed troughs are magnetically separated by magnetic separation rollers. Under the magnetic force of the magnets, the strongly magnetized particles are first adsorbed on the magnetic separation rollers and then fall into the separation bin, while the weakly magnetized particles fall directly into the separation bin. The advantage of this size-differentiation magnetic separation method is that it avoids the problem that large differences in particle size lead to significant differences in the distance between the particle's centroid and the magnet's surface, resulting in particles of the same grade not receiving equal magnetic separation opportunities and affecting magnetic separation efficiency.

[0011] This invention provides an offset magnetic separator, including a pre-selection chamber, a magnet, a separation chamber, and a residual separation chamber. The discharge port of the pre-selection chamber and the inlet of the residual separation chamber are arranged vertically and vertically respectively. The magnet is placed between the pre-selection chamber and the residual separation chamber. The magnetic lines of force generated by the magnet are generally as perpendicular as possible to the vertical line of the discharge port of the pre-selection chamber, and point towards or away from the magnet. The inlet of the separation chamber is close to the inlet of the residual separation chamber and is arranged on the same side as the magnet.

[0012] The discharge port of the pre-selection bin and the inlet of the residual selection bin are arranged vertically and vertically, forming a magnetically separated particle. The particles fall freely from the pre-selection bin outlet for a certain distance before entering the residual selection bin inlet. Magnets are positioned along one side of this distance. The discharge port of the pre-selection bin is preferably a narrow slit of equal width, creating a thin curtain of material as it falls, which improves magnetic separation efficiency. The discharge port is equipped with an on / off valve. The pre-selection bin can be closed, with the flow rate controlled by injecting oxygen-free gases such as nitrogen or carbon dioxide, and adjusting the gas pressure. Alternatively, the flow rate can be controlled using a rotary feeder, screw feeder, or other similar methods.

[0013] Preferably, the deflection magnetic separator further includes a sizing device, the outlet of which is connected to the inlet of the pre-selection chamber. The sizing device is selected from any one of a pneumatic screening device, a belt screening device, a chute screening device, or a vibrating screen screening device. The pre-selection chambers are arranged in close proximity to each other to receive different particle size groups sorted by the sizing device. The inlets of the sorting chambers are all located on the same horizontal plane, so that several different particle sizes can be selected at the same time. The magnet is an electromagnet and / or a permanent magnet; Preferably, the magnet is equipped with a magnet dust removal device, which is located on the side facing the particles to be magnetically separated.

[0014] Preferably, the deflection magnetic separator further includes a closed housing, which includes at least the area from the bottom outlet of the pre-selection chamber to the inlet of the residual and sorted chambers, with magnets enclosed inside or outside to minimize the influence of air resistance and improve sorting capacity.

[0015] In a further preferred embodiment, the enclosed housing is connected to a vacuum pump. For even higher vacuum levels, dual-valve pressure equalization mechanisms can be installed at the feed section of the pre-selection chamber, the discharge section of the selection chamber, and the discharge section of the residual selection chamber. Alternatively, the enclosed housing has an air inlet and a top equalization plate at the top, and an air outlet and a bottom equalization plate at the bottom. The air inlet and outlet are connected to the air outlet and inlet of an external circulating fan, respectively. A supplementary air inlet, essentially free of oxygen, is also provided on the air inlet side of the circulating fan. Nitrogen or carbon dioxide is typically used. If necessary, a bag filter dust collector is connected and installed on the air inlet side of the circulating fan. The injected air flows from top to bottom, essentially parallel to the direction of particle fall. The airflow speed is adjusted to offset the effects of air resistance and achieve optimal magnetic separation capability.

[0016] The present invention also provides a fall magnetic separation method, in which the particles to be magnetically separated are in a free fall state; a magnet is provided on one side along the fall path, and the magnetic field lines of the magnet are generally nearly horizontal and point towards or away from the side of the magnet (i.e., towards or away from the side where the magnet is located); the particles to be magnetically separated are screened according to the strength of magnetization under the action of magnetic force.

[0017] A magnetic field is installed along the falling path of the particles to be magnetically separated. The magnetic field lines are not parallel to the vertical line of the discharge port and are generally nearly horizontal, pointing to one side. Particles with different magnetizations experience different magnitudes of magnetic force during their fall, resulting in different horizontal accelerations in the direction of the magnetic field lines. Particles with stronger magnetization experience a greater magnetic force and thus a larger horizontal acceleration. Under the same initial horizontal velocity of zero, their falling trajectory deviates further from the vertical line of the discharge port in the direction generally pointing to one side. Utilizing this result, different inlets are used at the bottom to collect particles with different magnetizations along different trajectories, achieving the purpose of separating particles containing more magnetic substances. The advantage of this method is that by using the acceleration of falling particles under the influence of gravity, the distance between them increases, essentially eliminating the obstruction between particles and significantly improving the magnetic separation capacity.

[0018] Preferably, in the deflection magnetic separation method, the particles to be separated are in a vacuum state during their fall, or a downward airflow is applied during their fall to counteract air resistance.

[0019] In a further preferred embodiment, in the deflection magnetic separation method, the particles to be magnetically separated are first sorted into different particle size groups according to their particle size, and the different particle size groups enter different deflection magnetic separation processes for magnetic separation. Preferably, the particle size separation process uses the aforementioned particle size separation device.

[0020] The deflection magnetic separation method can be implemented using the aforementioned deflection magnetic separation device, and more specifically, the deflection magnetic separation method is as follows: After passing through the sizing device, the magnetically separated particles are sorted into different particle size groups, and the different particle size groups enter different pre-selection chambers. The magnetically separated particles are discharged from the discharge port of the pre-selection chamber and fall freely inside the sealed shell. During the fall, under the action of the magnetic force of the magnet, they are screened according to the strength of magnetization. The strongly magnetized particles are attracted by the magnet and their trajectory deviates and fall into the separation chamber, while the weakly magnetized particles fall into the separation residue chamber. Preferably, a vacuum pump is used to evacuate the sealed housing, ensuring the particles to be magnetically separated are in a vacuum state during their descent. Alternatively, gas is introduced into the sealed housing through an air inlet, applying a downward airflow to the falling particles to counteract air resistance. This invention discloses a chute-type magnetic separator, comprising a chute, a magnetic conveyor belt, a separation bin, and a separation residue bin. The chute forms an angle of 50 to 89 degrees with the horizontal plane, and the angle is adjustable. The magnetic separation conveyor belt is arranged above the side of the chute, and the distance between the magnetic separation conveyor belt and the chute is adjustable. The magnetic separation conveyor belt consists of an annular belt, an upper roller, a lower roller, a magnet, and a drive device. The upper roller and the lower roller are located at the upper and lower ends of the inner side of the annular belt, respectively. The drive device is used to drive the upper roller or the lower roller. The magnet is located inside the annular belt on the side closer to the chute. The width of the magnet is greater than the width of the chute. During operation, the position of the magnet is fixed. The magnetic separator conveyor belt has a sorting bin at its lower end and a sorting residue bin at its lower end. The lower end of the magnetic separator conveyor belt is lower than the lower end of the chute.

[0021] Preferably, the chute-type magnetic separator includes at least one inclined chute, the width of which is determined according to the production capacity, and the depth of which is selected according to the maximum particle diameter and the thickness of the material layer; the angle between the chute and the horizontal line is preferably 70 to 80 degrees; the magnet is an electromagnet and / or a permanent magnet; and a vibration mechanism is provided at the bottom of the chute.

[0022] More preferably, there are multiple chutes arranged side by side, and the width of the magnet is greater than the total width of the multiple chutes. The chute-type magnetic separator also includes the aforementioned sizing device, with each outlet of the sizing device connected to the inlet of each chute. The sizing device is selected from any one of a pneumatic screening device, a belt screening device, a chute screening device, or a vibrating screening device.

[0023] The present invention also provides a chute-type magnetic separation method, wherein the particles to be magnetically separated flow downward along the chute at a stable flow rate; during the flow, under the magnetic force of the magnet located above the chute, strongly magnetized particles and weakly magnetized particles are screened out.

[0024] The advantages of sluice-type magnetic separation are that it is largely unaffected by air resistance and that the particles are in a dynamic state in the sluice, which is conducive to improving the efficiency of magnetic separation.

[0025] Preferably, in the chute-type magnetic separation method, the particles to be magnetically separated are vibrated and dispersed as they flow along the chute.

[0026] Preferably, in the chute-type magnetic separation method, the particles to be magnetically separated are first sorted into different particle size groups according to their size, and the different particle size groups enter different deflection magnetic separation processes for magnetic separation. Preferably, the particle size separation process uses the aforementioned particle size separation device.

[0027] The chute magnetic separation method can be implemented using the aforementioned chute magnetic separation device, and more specifically, the chute magnetic separation method is as follows: After passing through the sizing device, the magnetically separated particles are sorted into different particle size groups, and the different particle size groups enter different sluices. The magnetically separated particles flow down the chute at a stable flow rate. During the flow, under the magnetic force of the magnet, the strongly magnetized particles are first adsorbed onto the magnetic separation conveyor belt and then enter the separation bin. The weakly magnetized particles flow out of the chute and enter the separation bin. Preferably, as the magnetically separated particles flow downward along the chute, a vibration mechanism is used to disperse the particles.

[0028] The present invention also provides a magnetic vibration separation device, including a pre-separation chamber, a magnetic vibration separation device, a separation chamber, and a separation residue chamber. The magnetic vibration separator is located below the discharge port of the pre-selection chamber. The magnetic vibration separator includes two electromagnetic field components. The two magnetic field components are composed of electromagnets arranged one above the other. The two magnetic field components are located on both sides of the vertical line of the discharge port of the pre-selection chamber and are arranged symmetrically. The two selection chamber inlets are located below the two magnetic field components, and the selection residue chamber inlet is located in the middle of the two selection chamber inlets.

[0029] Preferably, the electromagnets in both magnetic field components are vertically arranged; or, the electromagnets at the same height in both magnetic field components are arranged at the same angle and in the same direction, with adjacent electromagnets at the same angle but in opposite directions.

[0030] Preferably, it also includes a sizing device, each outlet of which is connected to the inlet of each pre-selection chamber. The sizing device is selected from any one of a pneumatic screening device, a belt screening device, a chute screening device, or a vibrating screening device.

[0031] This invention also provides a magnetic separation method using magnetic vibration, in which the particles to be separated are subjected to free fall to form a falling material flow. Openable and closable electromagnets are arranged at equal heights on both sides of the falling material flow. The openable and closable electromagnets on both sides at the same height are alternately opened and closed, and adjacent electromagnets on the same side are also alternately opened and closed. The alternating magnetic fields on both sides are used to separate strongly magnetized particles and weakly magnetized particles. During magnetic separation, the principle is that if one side of a segment at the same height is energized, the other side is de-energized, and vice versa; from top to bottom, if an adjacent segment is energized, the current segment is de-energized, and vice versa; the energizing cycle is adjusted to achieve a higher magnetic separation efficiency.

[0032] The magnetic separation method can be implemented using the aforementioned magnetic separation device, and more specifically, the magnetic separation method is as follows: After passing through the sizing device, the magnetically separated particles are sorted into different particle size groups, and the different particle size groups enter different pre-selection chambers. The particles of different sizes discharged from the pre-selection bin are in a free-fall state, forming a falling material flow. Following the rule that if one side of the same height segment is energized, the other side is de-energized, and from top to bottom, if adjacent segments are energized, the current segment is de-energized, the electromagnets in the two magnetic field components are energized or de-energized, and the strongly magnetized particles and weakly magnetized particles are separated by the alternating magnetic fields on both sides.

[0033] Strongly magnetized particles fall into the sorting bin, while weakly magnetized particles fall into the remaining bin.

[0034] The advantages of magnetic vibration separation are twofold: firstly, it involves alternating magnetic separation on both sides of the falling material flow; and secondly, it helps to eliminate agglomeration and improve magnetic separation efficiency.

[0035] Based on the above thin-layer magnetic separation method, a thin-layer magnetic separation device is provided, including a pre-separation chamber, a wide-band magnetic separator, a separation chamber, and a separation residue chamber; The pre-selection bin is located above the input end of the wide-band magnetic separator, while the selection bin and the residual bin are located below the output end of the wide-band magnetic separator. The broadband magnetic separator consists of a belt, an output roller, an input roller, a magnet, and a roller drive device. The magnet is installed inside the output roller, and the distance between the magnet and the output roller is adjustable. The discharge port of the pre-selection chamber is set in a long strip along the width of the belt, and the discharge port of the pre-selection chamber is biased towards the output end of the wide-band magnetic separator. Preferably, the discharge port of the pre-selection chamber is provided with multiple discharge nozzles evenly distributed along the width of the belt, and a vibrator is provided between the discharge port of the pre-selection chamber and the output end roller, with the vibrator located on the inner side of the upper layer of the belt.

[0036] Preferably, the thin-layer magnetic separator further includes a sizing device, the outlet of which is connected to the inlet of the pre-selection chamber. The sizing device is selected from any one of a pneumatic screening device, a belt screening device, a chute screening device, or a vibrating screening device.

[0037] Preferably, in the thin-layer magnetic separator, two wide-band magnetic separators are symmetrically arranged under the same pre-selection chamber. The pre-selection chamber has two discharge ports, which discharge materials to the two wide-band magnetic separators respectively. Preferably, multiple wide-band magnetic separators are arranged in upper and lower double or multiple layers. The pre-selection chamber has discharge ports corresponding to the number of wide-band magnetic separators, and each discharge port discharges materials to each wide-band magnetic separator respectively.

[0038] The present invention also provides a thin-layer magnetic separation method, in which the particles to be magnetically separated are distributed in a thin layer by means of cloth or cloth and vibration during the conveyor belt transport process. The particles to be magnetically separated are screened into strongly magnetic particles and weakly magnetic particles at the falling point under the action of a magnetic field.

[0039] The thin-layer magnetic separation method can be implemented using the aforementioned thin-layer magnetic separation device, and more specifically, the thin-layer magnetic separation method is as follows: After passing through the sizing device, the magnetically separated particles are sorted into different particle size groups, and the different particle size groups enter different pre-selection chambers. Particles of different sizes discharged from the pre-selection bin fall onto the belt surface of the wide-band magnetic separator. When they are conveyed to the output roller by the belt, under the action of the magnet, strongly magnetized particles fall into the separation bin, and weakly magnetized particles fall into the separation residue bin.

[0040] The advantages of thin-layer magnetic separation are twofold: firstly, it eliminates the mutual obstruction between material layers, and secondly, it brings the spacing between the particles to be separated and the magnets closer together, thereby improving the magnetic separation efficiency.

[0041] The present invention also discloses a direct steelmaking apparatus, including a fluidized bed apparatus, an electric furnace, and a magnetic separation apparatus. The magnetic separation apparatus is used to perform magnetic separation on the DRI powder reduced by the fluidized bed apparatus. The high-grade DRI powder after magnetic separation is directly fed into the electric furnace for steelmaking. The magnetic separation apparatus is any one of the above-mentioned sizing magnetic separation apparatus, deflection magnetic separation apparatus, chute magnetic separation apparatus, magnetic vibration magnetic separation apparatus, and thin-layer magnetic separation apparatus.

[0042] The present invention also discloses a direct steelmaking method using the above-mentioned direct steelmaking apparatus, the specific steps of which are: preparing DRI powder using the fluidized bed apparatus, and then sending the DRI powder through the magnetic separation device for magnetic separation and smelting in the electric furnace.

[0043] By adopting the above technical solution, the beneficial effects of the present invention are as follows: The magnetic separation device of this invention can effectively remove gangue from iron ore powder, improving the iron grade. This allows low-grade iron ore powder to be directly fed into the steelmaking process after reduction and magnetic separation, achieving low-carbon / zero-carbon direct steelmaking. By combining a fluidized bed device with the magnetic separation device of this invention, it can adapt to various types of iron ore powder, enabling direct steelmaking of multiple grades of iron ore powder. Attached Figure Description

[0044] Figure 1 This is a schematic diagram of the magnetic separation device for diameter division provided in Embodiment 2; Figure 2 This is a schematic diagram of the deflection magnetic separator provided in Embodiment 4; Figure 3 This is a schematic diagram of the chute-type magnetic separator provided in Embodiment 8; Figure 4 This is a schematic diagram of the magnetic resonant magnetic separator provided in Embodiment 12; Figure 5 This is a schematic diagram of the thin-layer magnetic separation device provided in Example 15; Figure 6 This is a schematic diagram of the electric arc furnace for melting DRI powder provided in Example 19; Figure 7 This is a schematic diagram of the integrated tailings processing device provided in Example 19; Figure 8 This is a schematic diagram of a direct steelmaking unit using a cooled multi-stage bubbling fluidized bed pure hydrogen magnetic separation method, as provided in Example 19. Figure 9 This is a schematic diagram of a direct steelmaking unit using a cooled multi-stage circulating fluidized bed low-carbon deflection magnetic separation provided in Example 20; Figure 10 This is a schematic diagram of a direct steelmaking unit using a cooled air-classified multi-layer cone bed pure hydrogen magnetic resonant separation, as provided in Example 21.

[0045] Among them, 101-cooled multi-stage bubbling fluidized bed group, 102-feed silo, 103-screw feeder, 104-H2 electrolytic cell, 105-storage tank, 106-gas source heater, 107-hydrogen compressor, 108-combustion chamber, 109-integrated device for tailings treatment, 110-heating chamber, 111-oxygen compressor, 112-air separation mechanism, 113-airlock valve, 114-tubular heat exchanger, 115-scrubber, 116-ceramic tube dust collector, 117-circulating compressor, 118-water treatment system, 119-Laval tube, 120-impact plate, 121-pre-selection silo feeder, 122-diameter magnetic separator, 123-electric arc furnace for smelting DRI powder, 124-pneumatic conveying device, 125-bag dust collector, 126-chimney, 127-fine material discharge pipe. 128 - Electric furnace; 129 - Slag ladle; 201-Circulating fluidized bed unit, 202-Grinding mill, 203-Feeding equipment, 204-Deflection magnetic separator, 205-Bulking machine, 206-Converter, 207-Gas generator, 208-Electric heater, 209-Carbon dioxide removal device, 210-Desulfurization device, 211-Raw ore bin, 212-Cyclone dust collector, 213-Blower; 304 - Air separator pipe, 313 - Feed pipe; 401-Air-separated multi-layer cone bed, 402-Magnetic vibration separator, 403-Bulking machine, 404-Bucket elevator, 405-Receiving bin, 406-Weighing bin, 407-Inlet bin, 408-Upper valve, 409-Lower valve; 601-Tailings bin, 602-Solvent bin, 603-Particle carbon bin, 604-Airlock feeder, 607-Tailings preheating bin, 608-Solvent preheating bin, 609-Particle carbon preheating bin, 610-Counterweight feeder, 613-Mixing feeder, 616-U-shaped slag outlet, 617-Iron outlet, 618-Electrode, 619-Air seal device, 620-U-shaped injection port, 621-Slag ladle, 622-Water spray device, 623-Slag storage and transportation device, 628-Iron ladle, 629-Air outlet, 630-Iron zone, 631-Slag zone, 632-Solid stockpile zone, 633-Furnace zone; 701-Church, 702-Church vibrator, 703-Magnetic separator conveyor belt, 704-Upper roller; 801-Multi-layer vibrating screen screening device, 802-Intermediate material trough, 803-Magnetic separation roller, 804-Residual material chute, 805-Output material chute, 806-Residual material bin, 807-Output material bin, 808-Dust cover, 809-Magnet, 810-Screw, 811-Screw bevel gear, 812-Control rod bevel gear, 813-Control rod, 814-Bearing seat, 815-Front selection bin; 901-Scraper, 902-Rope, 903-Fixed pulley, 904-Drive wheel, 905-Enclosed shell, 906-Top air distribution plate, 907-Bottom air distribution plate, 908-Circulating fan, 909-Settling chamber, 910-Air inlet; 1102-Wide-band magnetic separator, 1103-Small discharge nozzle, 1104-Vibrator, 1105-Support, 1106-Roller drive device; 1201-Feeder, 1202-Feeding pipe, 1203-Electrode, 1204-Rotating furnace cover, 1205-Fixed furnace cover, 1206-Furnace body, 1207-Furnace body rotating device, 1208-Smoke vent, 1209-Buffer chamber. Detailed Implementation

[0046] The present invention will be further described below with reference to the embodiments and accompanying drawings.

[0047] Example 1 A magnetic separator for diameter separation includes a diameter separation device, a magnetic separation roller, a separation bin, and a separation residue bin; The sizing device is selected from any one of the following: pneumatic screening device, belt screening device, chute screening device, or vibrating screen screening device; The sizing device is equipped with multiple discharge ports, each of which is equipped with a magnetic separation roller. The magnetic separation roller includes a magnet and a cylinder body. The magnet is located inside the cylinder body. During operation, the position of the magnet is fixed, while the cylinder body is rotating.

[0048] The separation chamber is located below the separation drop point of the magnetic separator roller, and the residual separation chamber is located below the residual separation drop point of the magnetic separator roller. The separation drop point is located below the non-magnetic area of ​​the magnetic separator roller, and the residual separation drop point is located below the magnetic area of ​​the magnetic separator roller.

[0049] The magnets are electromagnets, permanent magnets, or a combination of electromagnets and permanent magnets, and the distance between the magnets and the cylinder is adjustable.

[0050] Example 2 A type of magnetic separator, such as Figure 1 As shown, in this embodiment, the sizing device is specifically a multi-layer vibrating screen sizing device 801. Intermediate troughs 802 for receiving materials of different particle sizes are provided at the discharge port of each layer of vibrating screen and below the bottom layer of vibrating screen. A magnetic separator roller 803 is provided at the outlet of each intermediate trough 802. The magnet 809 built into the magnetic separator roller 803 can be an electromagnet or a permanent magnet. When a permanent magnet is built in, the magnet 809 is divided into multiple pieces along the circumference of the roller and arranged at a certain distance from the surface of the roller. A magnetic separation distance adjustment mechanism can be provided. The magnetic separation spacing adjustment mechanism includes a frame, a control rod 813, and multiple screws 810. The frame is provided with multiple bearing seats 814. The screws 810 are rotatably installed in the bearing seats 814. The axis of each screw 810 is the same as the radial direction of the cylinder. The control rod 813 coincides with the axis of the cylinder, that is, each screw 810 is perpendicular to the control rod 813. One end of each screw 810 is provided with a screw bevel gear 811. The control rod 813 is provided with a control rod bevel gear 812. The control rod bevel gear 812 meshes with the screw bevel gear 811. The screw 810 can only be driven to rotate by the screw bevel gear 811 and cannot move radially or circumferentially. Each magnet 809 has a threaded hole with internal threads, that is, the magnet 809 is equivalent to a nut. The magnet 809 is slidably connected in a guide groove that is parallel to the screw 810. It can only move radially and cannot rotate. The threaded hole is connected to the other end of the screw by a threaded engagement. By rotating the control lever 813, power can be transmitted to the screw 810 through the control lever bevel gear 812 and the screw bevel gear 811, causing the screw 810 to rotate, thereby adjusting the distance between the magnet 809 and the surface of the cylinder.

[0051] At the selection drop point of each magnetic separator roller 803, a selection chute 805 is provided, which is connected to the selection bin 807 below. At the selection drop point, a selection chute 804 is provided, which is connected to the selection bin 806 below.

[0052] The multi-layer vibrating screen screening device 801 and the intermediate material trough 802 are covered with dust covers 808.

[0053] Example 3 A magnetic separation method for particle size distribution uses the magnetic separation device provided in Example 1 or Example 2. The particles to be magnetically separated discharged from the pre-selection chamber 815 are separated into different particle size groups after passing through the multi-layer vibrating screen screening device 801. The particles to be magnetically separated in different particle size groups are magnetically separated by magnetic separation roller 803 to obtain strongly magnetic particles and weakly magnetic particles. Specifically, the particles to be magnetically separated in different particle size groups fall onto the outer surface of the cylinder of the magnetic separation roller 803 after passing through the intermediate material trough 802. The weakly magnetic particles fall into the residual selection chamber after leaving the outer surface of the cylinder at the selection residual drop point, and the strongly magnetic particles fall into the selection discharge chamber after leaving the outer surface of the cylinder at the selection discharge drop point.

[0054] Example 4 An offset magnetic separator, such as Figure 2 As shown, the system includes a pre-selection chamber 815, a magnet 809, a selection chamber 807, and a residual selection chamber 806. The outlet of the pre-selection chamber 815 and the inlet of the residual selection chamber 806 are arranged vertically correspondingly. The magnet 809 is located between the pre-selection chamber 815 and the residual selection chamber 806. The magnetic lines of force generated by the magnet 809 are generally as perpendicular as possible to the vertical line of the outlet of the pre-selection chamber 815 and point towards or away from the magnet. The inlet of the selection chamber 807 is close to the inlet of the residual selection chamber 806 and is arranged on the same side as the magnet. Several pre-selection chambers 815 for accepting different particle size groups are arranged in close proximity, and the inlets of the selection chambers 807 are all located on the same horizontal plane. The magnets are electromagnets and / or permanent magnets. A magnetic dust removal device is provided on the magnet 809. The magnetic dust removal device is located on the side facing the particles to be magnetically separated. The deflection magnetic separator also includes a pulley group consisting of a fixed pulley 903 and a drive wheel 904. A rope 902 is provided on the pulley group. In this embodiment, the magnetic dust removal device is a scraper 901. The scraper 901 is set on the rope 902 and is driven by the drive wheel 904 to perform the dust removal operation.

[0055] In this embodiment, the deflection magnetic separator further includes a closed housing 905, which at least includes the area extending from the bottom outlet of the pre-selection chamber 815 to the inlet of the residual selection chamber 806 and the sorting chamber 807, with the magnet 809 enclosed inside or outside. The enclosed housing 905 has an air inlet and a top air distribution plate 906 at the top, and an air outlet and a bottom air distribution plate 907 at the bottom. Outside the enclosed housing 905, a settling chamber 909, a supplementary air inlet 910, and a circulating fan 908 are connected sequentially from bottom to top. The circulating fan 908 is connected to the air inlet at the top of the enclosed housing 905, and the air outlet at the bottom of the enclosed housing 905 is connected to the settling chamber 909. This device is used to apply a downward airflow to the particles to be magnetically separated during their fall to counteract air resistance.

[0056] Example 5 An offset magnetic separator differs from Embodiment 4 in that the enclosed housing 905 does not have an air inlet and an air distribution plate, but is connected to a vacuum pump, and the magnetic separator also includes a sizing device. The outlet of the sizing device is connected to the inlet of the pre-selection chamber. The sizing device is selected from any one of a pneumatic screening device, a belt screening device, a chute screening device, or a vibrating screen screening device.

[0057] Example 6 A fall magnetic separation method uses the fall magnetic separation device provided in Example 4, so that the particles to be magnetically separated are in a free fall state; a magnet 809 is provided on one side along the fall path, and the magnetic lines of force are generally close to horizontal and point towards or away from the side of the magnet 809; the particles to be magnetically separated are screened according to the strength of magnetization under the action of magnetic force.

[0058] At the same time, a downward airflow is applied during the fall of the particles to be magnetically separated to counteract air resistance.

[0059] Example 7 An offset magnetic separation method differs from Embodiment 6 in that it uses the offset magnetic separation device provided in Embodiment 5. The particles to be magnetically separated are in a vacuum state during their fall, and the particles are first sorted into different particle size groups according to their size. Different particle size groups then enter different offset magnetic separation processes for magnetic separation. In this embodiment, the particle size separation process uses the particle size separation device provided in either Embodiment 1 or Embodiment 2.

[0060] Example 8 A chute-type magnetic separator, such as Figure 3 As shown, it includes a chute 701, a magnetic separation conveyor belt 703, a separation bin 807, and a separation residue bin 806. Specifically, it includes at least one inclined chute 701. The width of the chute is determined according to the production capacity, and the depth of the chute is selected according to the maximum particle diameter and the material layer thickness. The chute 701 forms an angle of 50 to 89 degrees with the horizontal plane and the angle is adjustable. The angle between the chute 701 and the horizontal line is preferably 70 to 80 degrees. The magnetic separation conveyor belt 703 is arranged on the side above the chute 701, and the distance between the magnetic separation conveyor belt 703 and the chute 701 is adjustable. The magnetic separation conveyor belt 703 consists of an annular belt, an upper roller 704, a lower roller, a magnet 809 and a drive device. The upper roller 704 and the lower roller are located at the upper and lower ends of the inner side of the annular belt, respectively. The drive device is used to drive the upper roller or the lower roller. The magnet 809 is located inside the annular belt on the side close to the chute 701, and the width of the magnet 809 is greater than the width of the chute 701. The magnetic separation conveyor belt 703 has a separation bin 807 arranged at its lower end, and the chute 701 has a separation residue bin 806 arranged at its lower end. The lower end of the magnetic separation conveyor belt 703 is lower than the lower end of the chute 701. Magnet 809 is an electromagnet and / or a permanent magnet; chute 701 is equipped with a chute vibrator 702 at the bottom.

[0061] Example 9 A chute-type magnetic separator, which differs from Embodiment 8, further includes a sizing device provided in either Embodiment 1 or Embodiment 2. Each outlet of the sizing device is connected to the inlet of each chute 701. The sizing device is selected from any one of a pneumatic screening device, a belt screening device, a chute screening device, or a vibrating screening device.

[0062] Example 10 A chute-type magnetic separation method uses the chute-type magnetic separation device provided in Example 8 to flow the particles to be magnetically separated downward along the chute 701 at a stable flow rate. During the flow, under the magnetic force of the magnet 809 located above the chute 701, strongly magnetized particles and weakly magnetized particles are screened out. At the same time, as the particles to be magnetically separated flow along the chute 701, the particles to be magnetically separated are vibrated and dispersed.

[0063] Example 11 A sluice-type magnetic separation method differs from Embodiment 10 in that it uses the sluice-type magnetic separation device provided in Embodiment 9. The particles to be magnetically separated are first sorted into different particle size groups, and the different particle size groups enter different sluice-type magnetic separation processes for magnetic separation. In this embodiment, the particle size separation process uses the particle size separation device provided in either Embodiment 1 or Embodiment 2.

[0064] Example 12 A magnetic resonant magnetic separator, such as Figure 4 As shown, it includes a pre-selection chamber 815, a magnetic vibration separator, a selection chamber, and a remaining selection chamber. The magnetic vibration separator is located below the discharge port of the pre-selection chamber 815. The magnetic vibration separator includes two magnetic field components, each composed of magnets 809 arranged vertically. The magnets 809 are electromagnets. The two magnetic field components are located on both sides of the vertical line of the discharge port of the pre-selection chamber 815, and the two magnetic field components are arranged symmetrically. The two separation chamber inlets are located below the two magnetic field components, and the separation residue chamber inlet is located in the middle of the two separation chamber inlets.

[0065] In this embodiment, the electromagnets in both magnetic field components are vertically arranged, and the lateral distance between the two magnetic field components is adjustable.

[0066] Example 13 A magnetic resonant magnetic separator differs from Embodiment 12 in that the electromagnets at the same height in the two magnetic field components are arranged at the same angle and in the same direction, and the electromagnets in adjacent segments are tilted at the same angle but in opposite directions.

[0067] Additionally, it includes a sizing device provided in either Embodiment 1 or Embodiment 2, with each outlet of the sizing device connected to the inlet of each pre-selection chamber 815. The sizing device is selected from any one of a pneumatic screening device, a belt screening device, a chute screening device, or a vibrating screening device.

[0068] Example 14 A magnetic separation method using a magnetic separation device provided in Example 12 or Example 13 involves placing the particles to be separated in a free-fall state to form a falling material flow. Openable and closable electromagnets are arranged at equal heights on both sides of the falling material flow. The openable and closable electromagnets on both sides at the same height are alternately opened and closed. Adjacent electromagnets on the same side are also alternately opened and closed. Strongly magnetized particles and weakly magnetized particles are separated using the alternating magnetic fields on both sides. During magnetic separation, if one side of a segment at the same height is energized, the other side is de-energized, and vice versa. From top to bottom, if an adjacent segment is energized, the current segment is de-energized, and vice versa. The energizing and de-energizing cycle is adjusted to achieve a higher magnetic separation efficiency.

[0069] The advantages of magnetic vibration separation are twofold: firstly, it involves alternating magnetic separation on both sides of the falling material flow; and secondly, it helps to eliminate agglomeration and improve magnetic separation efficiency.

[0070] Example 15 A thin-layer magnetic separator, such as Figure 5 As shown, it includes a pre-selection bin 815, a wide-band magnetic separator 1102, a selection bin 807, and a residual selection bin 806; The pre-selection chamber 815 is located above the input end of the wideband magnetic separator 1102, while the selection chamber and the remaining selection chamber are located below the output end of the wideband magnetic separator 1102. The discharge port of the pre-selection chamber 815 is elongated along the width of the belt, and the discharge port of the pre-selection chamber 815 is biased towards the output end of the wide-band magnetic separator 1102. The broadband magnetic separator 1102 consists of a belt, an output roller, an input roller, a magnet 809, and a roller drive device 1106. The magnet 809 is installed inside the output roller, and the distance between the magnet 809 and the output roller is adjustable. It can be adjusted using the magnetic separation distance adjustment mechanism in Embodiment 2.

[0071] The sorting bin is located below the area where the magnet 809 is located on the output roller, and the sorting bin is located below the area where the non-magnet 809 is located on the output roller. Specifically, the discharge port of the sorting bin 815 is evenly provided with multiple small discharge nozzles 1103 along the width direction of the belt, and a vibrator 1104 is provided between the discharge port of the sorting bin 815 and the output roller. The vibrator 1104 is located on the inner side of the upper layer of the belt and is mounted on the bracket 1105.

[0072] Example 16 A thin-layer magnetic separator, which differs from Embodiment 15, further includes a sizing device. The outlet of the sizing device is connected to the inlet of the pre-selection chamber 815. The sizing device is selected from any one of a pneumatic screening device, a belt screening device, a chute screening device, or a vibrating screening device.

[0073] Meanwhile, two broadband magnetic separators 1102 are symmetrically arranged under the same pre-selection chamber 815. The pre-selection chamber 815 is provided with two discharge ports, which discharge materials to the two broadband magnetic separators respectively. Preferably, multiple broadband magnetic separators are arranged in upper and lower double or multi-layer configurations. The pre-selection chamber is provided with discharge ports corresponding to the number of broadband magnetic separators, and each discharge port discharges materials to each broadband magnetic separator respectively.

[0074] Example 17 A thin-layer magnetic separation method, using the thin-layer magnetic separation device provided in Example 15, achieves a thin-layer distribution of the particles to be magnetically separated by cloth or cloth and vibration during the conveyor belt transport of the particles to be magnetically separated. The particles to be magnetically separated are screened into strongly magnetic particles and weakly magnetic particles at the falling point under the action of a magnetic field.

[0075] Example 18 A thin-layer magnetic separation method using the thin-layer magnetic separation device provided in Example 16 differs from Example 17 in that the particles to be magnetically separated are first sorted into different particle size groups according to their particle size, and the different particle size groups enter different thin-layer magnetic separation processes for magnetic separation.

[0076] Example 19 To facilitate a clearer understanding of the technical solution of the present invention by those skilled in the art, this embodiment discloses a detailed direct steelmaking method. The direct steelmaking method of this embodiment adopts a cooling multi-stage bubbling fluidized bed pure hydrogen magnetic separation method, that is, using a cooling multi-stage bubbling fluidized bed group for reduction + pure hydrogen reducing gas + magnetic separation using a magnetic separation device.

[0077] like Figure 8 As shown, low-grade Brazilian iron ore powder containing 60% iron is fed into a cooling multi-stage bubbling fluidized bed group 101 via a feed hopper 102 and a screw feeder 103. The bed group consists of five fluidized beds. Figure 8 From right to left, the fluidized beds are arranged in five stages: first, second, third, fourth, and fifth (shown as R1, R2, R3, R4, and R5 in the diagram). Material with a particle size ≤0.3mm is pre-loaded into the fifth fluidized bed through the inspection port, while material with a particle size >0.3mm is pre-loaded into the second, third, and fourth fluidized beds. Hydrogen produced by the H2 electrolyzer 104 is compressed by the hydrogen compressor 107 and stored in the storage tank 105. Hydrogen exiting the storage tank 105 then enters the gas source heater 106. Combustion chamber 108 is introduced with some oxygen produced during the electrolysis process. It is used to burn a mixture of recycled hot hydrogen that has not been dehydrated and tail gas from tailings furnace 109. The high-temperature exhaust gas from the combustion is heated to a higher temperature by gas source heater 106. Then, a small amount of oxygen is added by oxygen compressor 111 and the hydrogen is heated by combustion in heating chamber 110. Finally, the hydrogen is heated to 1050 degrees and enters the cooled multi-stage bubbling fluidized bed group 101 from the fourth fluidized bed gas distribution chamber.

[0078] When the fluidized bed reaches a bubbling fluidization state and the metallization rate of large particles reaches 95%, iron ore powder can be continuously fed into the fourth-stage fluidized bed according to the design flow rate. After passing through the air separation mechanism 112 located in the fourth-stage fluidized bed, fine particles ≤0.3 mm enter the fifth-stage fluidized bed through the air separation pipe 304. The remaining large particles enter the fourth-stage fluidized bed through the feed pipe 313, undergo fluidization and reduction in the fourth-stage bed, and then enter the third-stage fluidized bed through the discharge pipe of the fourth-stage fluidized bed and the airlock valve 113. The same process is then repeated in the second-stage and first-stage fluidized beds.

[0079] The first-stage fluidized bed is a cooled reduction bed. Unheated, room-temperature hydrogen gas is blown in from the bottom gas distribution chamber through the gas distribution plate at half the flow rate of heated hydrogen gas. Hydrogen gas at 1050 degrees Celsius enters from the gas distribution chamber of the second-stage fluidized bed, mixing with cooled hydrogen gas from the first-stage fluidized bed after cooling DRI powder, resulting in a temperature of 900 degrees Celsius before entering the second-stage fluidized bed. It then passes through a built-in cyclone dust collector at the top and exits from the top of the second-stage fluidized bed, entering the gas distribution chamber of the third-stage fluidized bed through a pipe. After passing through the gas distribution plate, the bed, and the built-in cyclone dust collector, it exits, and similarly enters the fourth and fifth-stage fluidized beds. The hydrogen gas undergoes a high-temperature reduction reaction with iron ore at each fluidized bed layer, producing water which enters the tail gas as steam.

[0080] The exhaust gas, ultimately discharged from the top of the fifth-stage fluidized bed via a built-in cyclone dust collector, has a very small portion returning to the combustion chamber 108 as fuel or mixed with the exhaust gas from the tail gas furnace to burn and heat hydrogen, or burned with oxygen and then mixed with the tail gas furnace exhaust gas to heat hydrogen. The vast majority enters the exhaust gas treatment system, undergoing fine dust removal by the ceramic tube dust collector 116, cooling on the hot side of the tubular heat exchanger 114, dehydrating in the scrubber 115, pressurizing by the circulating compressor 117, and then reheating on the cold side of the tubular heat exchanger 114 before returning to the gas source heater 106 at the front of the fluidized bed for recycling. The water discharged from the scrubber 115 is returned to the electrolytic cell 104 for recycling after passing through the water treatment system 118. The gas discharged from the gas source heater 106 is treated by the bag filter 125 and then discharged through the chimney 126.

[0081] The reduction temperature of the fifth-stage fluidized bed is 620~650 degrees Celsius to avoid fine particles from agglomerating and losing flow.

[0082] The DRl powder that has undergone reduction in the second-stage fluidized bed has a temperature of 860 degrees Celsius, and its temperature after cooling in the first-stage fluidized bed is 120 degrees Celsius.

[0083] The airflow is accelerated to supersonic speed by the Laval pipe 119 installed on the discharge pipe of the first-stage cooling fluidized bed. The ejected particles impact the impact plate 120 in the pre-selection chamber. The flow rate is controlled by the valve at the inlet of the discharge pipe. After the crushed particles fall into the pre-selection chamber 815, the fine particles DRⅠ that have been reduced by the fifth-stage fluidized bed also enter the pre-selection chamber 815 through the fine material discharge pipe 127. The pre-selection chamber feeder 121 installed at the discharge port of the pre-selection chamber 815 distributes the material onto the multi-layer vibrating screen 801 of the sizing magnetic separator 122. The sizing magnetic separator 122 here is the sizing magnetic separator in the above embodiment. The vibrating screen 801 has four layers, which divides the particles into five particle size groups: ≥1.5~1.0~0.5~0.2~0mm. Magnetic separation is performed on five magnetic separation rollers 803 arranged through an intermediate chute 802. Approximately 80% of the separated material enters the separation chamber 807 with a grade of about 90%, while the remaining 20% ​​enters the residual separation chamber 806 with a grade of about 47%. The hydrogen gas entering the pre-selection chamber 815 is at approximately 100 degrees Celsius. After being filtered by filter bags, the hydrogen gas exits the pre-selection chamber 815 and is then piped into the purified and recycled hydrogen gas.

[0084] The pneumatic conveying device 124 located at the lower part of the selection bin 807 transports the selected DR1 powder to the buffer bin 1209 at the top of the DRⅠ powder melting electric arc furnace 123. The specific structure of the DRⅠ powder melting electric arc furnace 123 is as follows: Figure 5As shown, it should be noted that this electric arc furnace 123 is not existing technology. Through three spiral feeders 1201 and three feed pipes 1202, DRⅠ powder can be delivered to the lower arc zone of the three electrodes 1203. The rotating furnace cover 1204 is opened. Scrap steel, auxiliary materials, and molten iron from the tailings furnace 109 are added. After the cover is closed, the electrodes 1203 are lowered for smelting. Once a slag surface has formed at the lower end of the electrodes 1203, DRⅠ powder is continuously added to continue smelting. During the above process, slag-forming agents and ferroalloys required for the steel grade also need to be added. After steelmaking is completed, the steel is tapped, and then the slag is removed. If no scrap steel is added during the smelting process, the slag liquid can be directly water-quenched by tempering during steelmaking to meet the conditions for direct water quenching. If it is mixed with scrap steel for smelting, the slag liquid can be treated in accordance with existing technology. Preferably, the slag liquid is stored in steel slag tank 129 and transported to integrated tailings treatment device 109. After being mixed and modified by integrated tailings treatment device 109, water slag is produced.

[0085] The remaining material in the tailings bin 806 is the tailings. It is fed into the tailings bin 601 of the integrated tailings processing device 109 via a pneumatic conveying device 124 at the bottom of the tailings bin 806. From there, it enters the tailings furnace via a dispensing feeder 610 and a mixing feeder 613, continuously pushing the tailings into the arc zone of the tailings furnace electrode 618. Simultaneously, appropriate amounts of solvent (such as lime) and carbon powder are added through the flux bin 602 and granular carbon bin 603 to maintain the carbon content of the produced molten iron and the water-quenched slag properties in accordance with national standards. The produced molten iron is stored in an iron ladle 628 and then transported to the DRI powder electric arc furnace 123 for smelting.

[0086] The electric arc furnace 123 used in this embodiment for melting DRI powder is as follows: Figure 6 As shown, it includes a furnace body 1206, a furnace body rotating device 1207, a DRI powder feeding device, a furnace cover, a furnace cover driving device, an electrode 1203, an electrode driving device, an electrode power supply device, a flue gas vent 1208, a flue gas purification output system, an auxiliary material pipe, and an auxiliary material feeding device. The furnace body rotation device 1207 is connected to the furnace body 1206 and is used to control the tilting of the furnace body 1206 to achieve operations such as steel tapping and slag removal. The furnace cover drive device is connected to the furnace cover and is used to drive the furnace cover to rotate, realizing the opening and closing of the furnace cover to meet the needs of operations such as charging and maintenance. The electrode 1203 extends from the furnace cover into the furnace body 1206. The electrode power supply device and the electrode drive device are both connected to the electrode 1203. The electrode power supply device is used to supply power to the electrode 1203, and the electrode drive device is used to drive the electrode 1203 to rise and fall. The flue gas vent 1208 is set on the furnace cover and is connected to the flue gas purification and output system for purifying the flue gas discharged from the electric furnace before discharge. The auxiliary material pipe is connected to the auxiliary material feeding device. The auxiliary material pipe can be set on the furnace body 1206 for adding auxiliary materials, such as slag-forming agents, into the furnace. The specific structure of this part can be set with reference to the existing electric furnace, so it will not be described in detail.

[0087] The DRI feeding device includes a buffer silo 1209, a feeder 1201, and a feed pipe 1202. The buffer silo 1209 is equipped with a dust removal system. The feeder 1201 is connected to the lower outlet of the buffer silo 1209, and the upper end of the feed pipe 1202 is connected to the outlet of the feeder 1201. The DRI powder feeding device is equipped with a nitrogen or carbon dioxide priming protection system.

[0088] In the electric arc furnace for steelmaking, the connection relationship between the feed pipe 1202 and the furnace cover is as follows: a) The furnace cover is divided into a fixed furnace cover 1205 and a rotating furnace cover 1204. The rotating furnace cover 1204 is driven to rotate by a furnace cover driving device.

[0089] The feed pipe 1202 is divided into branches corresponding to the number of electrodes, and is inserted into the furnace from the fixed furnace cover 1205. The height and angle of the discharge port of each branch feed pipe 1202 are such that the powder being fed falls near the corresponding electrode arc area. Figure 6 As shown; b) The furnace cover is a rotating furnace cover. The feed pipe 1202 is provided with several branch outlets. Each branch feed pipe is divided into upper and lower sections. The lower section is fixed on the rotating furnace cover and passes through the rotating furnace cover and extends into the furnace body. Preferably, the lower section is connected to a material distribution pipe that is inclined around the corresponding electrode. Multiple discharge ports are opened below the annular material distribution pipe. The upper opening of the upper section is rotatably connected to the branch outlet of the feed pipe. The upper section can swing. When the rotating furnace cover is on the furnace body, the swing of the upper section can make its lower opening align with the upper opening of the corresponding branch feed pipe lower section, so that the axes of the two openings coincide.

[0090] The steelmaking method of the electric arc furnace using this scheme is as follows: DRI powder is supplied into the electric furnace, allowing the continuously added powder to enter the vicinity of the electric arc zone, thereby achieving efficient melting upon entry into the furnace. Specifically, the DRI powder is transported to the electric arc zone of the electrode through a buffer hopper 1209, a feeder 1201, and a feed pipe 1202. The flow rate of the DRI powder is controlled to match the melting capacity of the electrode 1203. A continuous feeding method is adopted, ensuring that the continuously added DRI powder first enters the electric arc zone to achieve efficient melting. The process is protected by nitrogen, carbon dioxide, or waste gas to prevent oxidation. The advantages of this steelmaking method are that it not only solves the problem of ice formation during powder melting but also improves smelting efficiency, while seamlessly integrating with traditional scrap steel-using steelmaking processes.

[0091] The integrated tailings processing device 109 used in this embodiment, such as... Figure 7 As shown, it includes a material delivery system, a smelting system, a slag treatment system, and a molten iron system; The material delivery system is used to transport tailings into the smelting system; The material delivery system can be one of the following three forms: The first type: The material delivery system includes a tailings bin 601, a flux bin 602, and a granular carbon bin 603. The outlet of each bin is connected to an airlock feeder 604, which is then connected to a tailings preheating bin 607, a flux preheating bin 608, and a granular carbon preheating bin 609. The outlet of each preheating bin is connected to a metering feeder 610 for that bin. Each metering feeder 610 is connected to a mixing feeder 613 connected to the tailings furnace. The mixing feeder 613 is used to transport materials to the solid stockpile area 632 in the tailings furnace. Each preheating bin has several air inlets at its cone section that are connected to the tailings furnace air outlet 629. Each preheating bin has an air outlet at its top that is connected to the furnace gas purification output system or a subsequent utilization system. The second method: The feeding system can also combine the three preheating bins into one, that is, the outlets of the tailings bin 601, flux bin 602 and granular carbon bin 603 are all connected to their respective dispensing feeders 610, each dispensing feeder 610 is connected to the same mixing feeder, the outlet of the mixing feeder is connected to the inlet of the combined preheating bin, and the outlet of the preheating bin is connected to the furnace body of the tailings furnace through a screw feeder; The third type: The feeding system is a tailings injection device, in which tailings are injected into the slag pool inside the tailings furnace through the spray gun of the tailings injection device.

[0092] The smelting system includes a tailings furnace, which consists of a shell, furnace base, refractory materials, and cooling walls. From bottom to top, the furnace body comprises an iron zone 630, a slag zone 631, and a furnace chamber 633. The furnace chamber 633 has a feed inlet, and at its top are a gas outlet 629, an electrode inlet, and a gas sealing device 619, using nitrogen or carbon dioxide as the sealing gas. Outside the furnace are electrodes 618, electrode clamping devices, and a power distribution device. Electrodes 618 enter the tailings furnace through the electrode inlet. Preferably, the top of the furnace chamber 633 also has a liquid steel slag inlet. The slag zone 631 has a U-shaped inlet 620 through which the slag from the electric furnace and / or converter is injected. The slag or liquid steel slag is fed into the tailings furnace and melted and mixed with the tailings slag. If necessary, the flux ratio can be adjusted during the steelmaking process to meet the composition requirements for producing qualified slag after mixing with the tailings slag. The slag zone 631 is also equipped with a U-shaped slag outlet 616. Whether or not slag is discharged from the tailings furnace is controlled by adjusting the furnace pressure through the pressure regulating valve group of the furnace gas treatment system. A tiltable slag ladle 621 is provided at the U-shaped slag outlet 616, and the slag ladle 621 is equipped with insulation and / or an electric heating device. The molten iron zone 630 is equipped with a taphole 617. The slag treatment system is located below the slag ladle 621. After the slag ladle 621 is filled with molten slag, it is tilted out for water quenching. This process facilitates the mixing of the slag and liquid components. The slag treatment system includes a water spraying device 622 located below the slag ladle 621, and a water slag storage and transportation device 623 and a water treatment device sequentially connected to the water spraying device 622. The molten iron system includes a molten iron ladle 628 located below the taphole 617, and a steelmaking conveying device and a casting machine sequentially connected to the molten iron ladle 628. The tailings furnace body is equipped with maintenance holes for easy access for personnel to inspect and maintain the furnace. The U-shaped slag outlet 616 is a U-shaped liquid-sealed slag outlet; the tailings furnace is also equipped with an oxygen-containing gas inlet; the tailings preheating chamber 607, flux preheating chamber 608, and granular carbon preheating chamber 609 are arranged in a hyperbolic conical shape.

[0093] Meanwhile, in the integrated device, the connection method between the mixing feeder in the first method and the screw feeder in the second method and the feed inlet of the tailings furnace is one of the following: I. The feed inlet is located on the side wall of the tailings furnace in the furnace zone, and the outlet of the mixing feeder or screw feeder is connected to the feed inlet; II. The tailings furnace is equipped with a feed pipe. One end of the feed pipe is connected to the outlet of the mixing feeder or the screw feeder, and the other end of the feed pipe is a feed inlet. The feed inlet is connected to an annular material distribution pipe that is inclined around the motor. III. The tailings furnace is equipped with a feed pipe. One end of the feed pipe is connected to the outlet of the mixing feeder or the screw feeder, and the other end of the feed pipe is the inlet. The inlet is arranged at a suitable height and angle for each electrode so that the tailings can be thrown to the vicinity of the arc zone released by the electrode.

[0094] The tailings processing method using the integrated tailings processing device 109 of this embodiment is as follows: Tailings, flux (limestone, dolomite, etc.) and granular carbon (coke powder, carbon powder, etc.) are mixed to form a mixture, which is then fed into a tailings furnace and heated and melted by releasing an electric arc from the electrodes. The tailings are added in the form of powder. The method of feeding the mixture into the tailings furnace is selected from any of the following: When the connection method between the mixing feeder or screw feeder and the inlet of the tailings furnace is I: a) When the mixture is fed into the tailings furnace, it is buried in the solid material pile inside the furnace. The solid material is allowed to enter by applying pressure to the solid material at the feed port. When the connection method between the mixing feeder or screw feeder and the inlet of the tailings furnace is III: b) The mixture is thrown into the area where the electrodes release the electric arc through the feed pipe extending into the tailings furnace; When the connection method between the mixing feeder or screw feeder and the inlet of the tailings furnace is II: c) The mixture enters the tailings furnace through the feed pipe and is arranged in the area where the electrode releases the electric arc through the inclined annular distribution pipe that surrounds the electrode. When the feeding system is a tailings injection device: d) When the mixture is fed into the tailings furnace, it is sprayed into the slag pool through the spray gun of the tailings injection device.

[0095] The molten slag from the electric furnace and / or converter is fed into the tailings furnace through a U-shaped inlet to melt and mix with the tailings slag. After the molten slag in the tailings furnace is discharged through the U-shaped slag outlet, it is mixed in a slag ladle and then discharged from the ladle for slag treatment. The by-product molten iron produced during the slag melting process in the tailings furnace flows from the tapping port into the molten iron ladle and is cast into block iron or foundry iron or directly sent into the steelmaking furnace. The furnace gas flows out from the outlet 629, and its sensible heat and / or chemical heat are used for drying and preheating of the tailings, solvents, and carbon particles entering the tailings furnace.

[0096] Example 20 The direct steelmaking method in this embodiment is a direct steelmaking method using a cooled multi-stage circulating fluidized bed with low-carbon deflection magnetic separation, that is, using a cooled multi-stage circulating fluidized bed group for reduction + low-carbon reducing gas + deflection magnetic separation device for magnetic separation.

[0097] like Figure 9 As shown, there are only five differences from Example 19: First, the fluidized bed group selected is four conventional circulating fluidized bed groups 201. Its operation process is the same as that of conventional circulating fluidized beds, so it will not be repeated here. The only difference is that the operating temperature of the first-stage fluidized bed does not exceed 700 degrees. The second, third and fourth-stage fluidized beds are appropriately supplemented with heat reducing gas so that the reduction temperature of the second and third beds is between 550 and 700 degrees, and the fourth bed is around 500 degrees.

[0098] Secondly, the fine crushing process is placed before the fluidized reduction process. The raw ore bin 211 sends the coarse ore powder to the grinding mill 202. The hot air obtained by the blower 213 and the heat exchanger 114 enters the grinding mill 202 and is used to transport the fine ore powder ground by the grinding mill 202 to the cyclone dust collector 212. The powder is then fed into the fourth-stage fluidized bed through the feeding device 203, with a particle size of 100~200 mesh.

[0099] Third, magnetic separation is placed between the fourth-stage fluidized bed and the third-stage fluidized bed, using an offset magnetic separator 204. This offset magnetic separator 204 is the same as described in the previous embodiment, eliminating the need for the pre-separation chamber 815, which is replaced by the discharge pipe of the cyclone dust collector in the fourth-stage fluidized bed. The magnetic separation temperature is 400-500 degrees Celsius. The DRI powder from the first-stage fluidized bed is directly conveyed hot to the DRI powder melting electric arc furnace 123 using a pneumatic conveying device 124, or pressed into briquettes by the briquetting machine 205 and then sent to the converter 206.

[0100] Fourth, the reducing gas generating device selected is gasifier 207. If the temperature of gasifier 207 is insufficient, electric heater 208 can be used to raise the temperature, or a small amount of oxygen can be injected for combustion to raise the temperature.

[0101] Fifth, the gas purification system is equipped with a carbon dioxide removal device 209 and a desulfurization device 210. The exhaust gas discharged from the cyclone dust collector of the fourth-stage fluidized bed is finely dusted by the ceramic tube dust collector 116. After being cooled on the hot side of the tubular heat exchanger 114, the exhaust gas enters the scrubber 115 for dehydration, the desulfurization device 210 for desulfurization, and the carbon dioxide removal device 209 for CO2 removal. After being pressurized by the circulating compressor 117, it enters the tubular heat exchanger 114 for heating on the cold side and then returns to the electric heater 208 at the front of the fluidized bed group for recycling.

[0102] Everything else is the same as in Example 19. It should be noted that, since the remaining iron ore powder has not yet begun metallization, the tailings furnace of the integrated tailings processing device 109 needs to have more carbon or coal powder added, increasing the gas volume in the tailings furnace so that it can be combined with the gas source from the gas generator and enter the fluidized bed group. Therefore, the tailings furnace design must meet the requirements for high-pressure operation.

[0103] Example 21 A direct steelmaking method employing a cooled air-classified multi-layer conical bed for pure hydrogen magnetic separation involves using a cooled air-classified multi-layer conical bed (a multi-layer conical fluidized bed containing an air-classification mechanism and a cooling bed) + pure hydrogen reducing gas + magnetic separation using a magnetic separation device.

[0104] like Figure 10 As shown, the differences from Example 19 are: First, the fluidized bed group uses a multi-layer conical air classifier 401 with 5 layers. The bottom fluidized bed is a cooling bed. Iron ore powder enters the multi-layer conical air classifier 401 from the second-to-top fluidized bed. Fine particles enter the top fluidized bed for reduction. The reduced fine particles are discharged from the multi-layer conical air classifier 401. Coarse particles are reduced from the second-to-top fluidized bed and then enter the lower fluidized bed layers through the feed pipe for further reduction. Finally, they are discharged from the bottom fluidized bed. Both coarse and fine particles discharged from the multi-layer conical air classifier 401 pass through the Laval pipe 119, which makes the airflow supersonic. The ejected particles impact the impact plate 120 in the pre-selection chamber. The flow rate is controlled by the valve at the inlet of the discharge pipe. The crushed particles fall into the pre-selection chamber.

[0105] Secondly, a magnetic separation device 402 is used below the pre-selection bin 815 for magnetic separation. The magnetic separation device 402 is the same as the one described in the previous embodiment, with an adjustable spacing of 50-200mm between the electromagnets on both sides, a width of 1000mm, a total height of 3000mm, and is divided into ten magnet segments. The temperature of the DRⅠ powder during magnetic separation is approximately 700 degrees Celsius. The separated portion enters the separation bin 807, then the briquetting machine 403. After briquetting, it is sent to the receiving bin 405 of the DRⅠ hot briquetting feeder for the electric furnace via a bucket elevator 404. It then enters the weighing bin 406 through the upper valve 408, and finally enters the electric furnace 128 through the inlet bin via the lower valve 409. A standard electric furnace can be selected. Nitrogen protection is used throughout the process to prevent oxidation. Alternatively, it can be supplied to a converter for steelmaking.

[0106] The rest are the same as in Example 19.

Claims

1. A differential magnetic separation device, characterized in that, The device comprises a size sorting device, a magnetic roller, a selected bin and a remaining bin. The size sorting device is selected from any one of a wind sifting device, a belt sifting device, a chute sifting device or a vibrating screen sifting device. The size sorting device is provided with a plurality of discharge ports, and a magnetic roller is arranged at each discharge port. The selected bin is arranged below the selected drop-off point of the magnetic roller, and the remaining bin is arranged below the remaining drop-off point of the magnetic roller. Preferably, the magnet is selected from an electromagnet and / or a permanent magnet, and the distance between the magnet and the cylinder body is adjustable.

2. A method of diamagnetic separation, characterized in that The particles to be magnetically sorted are sorted into different size groups according to particle size, and the particles to be magnetically sorted in different size groups are respectively subjected to magnetic sorting and screening by the magnetic sorting device to obtain strongly magnetized particles and weakly magnetized particles.

3. A device for magnetic separation by deflection, characterized in that The device comprises a pre-selection bin, a magnet, a selected bin and a remaining bin, the discharge port of the pre-selection bin is arranged in correspondence with the inlet of the remaining bin, the magnet is arranged between the pre-selection bin and the remaining bin, and the magnetic force line of the magnet is perpendicular to the drop line of the discharge port of the pre-selection bin and points to or away from the magnet. The inlet of the selected bin is close to the inlet of the remaining bin and arranged on the same side as the magnet.

4. A device according to claim 3, wherein the magnetic field is arranged to be switched between the first and second configurations by means of a magnetic field switching means. The device further comprises a size sorting device, the outlet of the size sorting device is connected to the inlet of the pre-selection bin, and the size sorting device is selected from any one of a wind sifting device, a belt sifting device, a chute sifting device or a vibrating screen sifting device. The pre-selection bin is provided with a plurality of discharge ports, and the inlets of the selected bins are arranged on the same horizontal plane. The magnet is an electromagnet and / or a permanent magnet. Preferably, a magnet dust cleaning device is arranged on the magnet, and the magnet dust cleaning device is arranged on the side facing the particles to be magnetically sorted.

5. A device according to any one of claims 3 or 4, wherein the device is a device for magnetic separation. The device further comprises an enclosed housing, the enclosed housing at least contains the area from the discharge port of the pre-selection bin to the inlets of the selected bin and the remaining bin, and the magnet is enclosed in or outside the enclosed housing. The enclosed housing is connected with a vacuum pump, or the top of the enclosed housing is provided with an air inlet and a top air equalization plate, and the bottom of the enclosed housing is provided with an air outlet and a bottom air equalization plate.

6. A method of magnetic separation by eddy current, characterized in that, The particles to be magnetically sorted are in a free-falling state, a magnet is arranged on one side of the falling path, the magnetic force line of the magnet is generally horizontal and points to or away from one side of the magnet, and the particles to be magnetically sorted are screened according to the strength of magnetization under the action of the magnetic force.

7. The method of claim 6, wherein the magnetic separation is a cross flow magnetic separation. The device further comprises one or more of the following features: The particles to be magnetically sorted are in a vacuum state during the falling process, or a downward air flow is applied to offset air resistance during the falling process of the particles to be magnetically sorted. The particles to be magnetically sorted are first sorted into different size groups according to particle size, and the particles to be magnetically sorted in different size groups enter different magnetic sorting processes for magnetic sorting.

8. A trough-type magnetic separation device, characterized by The device comprises a chute, a magnetic conveying belt, a selected bin and a remaining bin. The angle between the chute and the horizontal plane is 50 to 89 degrees and is adjustable. The magnetic conveying belt is arranged above the side of the chute, the distance between the magnetic conveying belt and the chute is adjustable, the magnetic conveying belt is composed of a ring belt, an upper roller, a lower roller, a magnet and a driving device, the upper roller and the lower roller are respectively arranged at the upper end and the lower end of the inner side of the ring belt, the driving device is used to drive the upper roller or the lower roller, the magnet is arranged inside the ring belt close to the chute, and the width of the magnet is greater than the width of the chute. The lower end of the magnetic separation conveying belt is provided with a selected bin, and the lower end of the chute is provided with a selected remaining bin, and the lower end of the magnetic separation conveying belt is lower than the lower end of the chute.

9. A trough-type magnetic separation device according to claim 8, characterized in that The device comprises at least one inclined chute, the angle between the chute and the horizontal line is preferably 70-80 degrees; the magnet is selected from an electromagnet and / or a permanent magnet; and preferably, a vibration mechanism is arranged at the bottom of the chute.

10. A trough-type magnetic separation device according to any one of claims 8 or 9, characterized in that, The device further comprises a size separation device, and the outlets of the size separation device are connected to the inlets of the chutes.

11. A method of slot magnetic separation, characterized by The device further comprises the following one or more features:

12. The trough-type magnetic separation method as claimed in claim 11, characterized in that, The device further comprises the following one or more features: The device further comprises the following one or more features: The device comprises a pre-selection bin, a magnetic vibration separation device, a selected bin, and a selected remaining bin.

13. A magnetic resonance magnetic separation device, characterized by The magnetic vibration separation device is arranged below the discharge port of the pre-selection bin, and the magnetic vibration separation device comprises two magnetic field assemblies, each of which comprises an electromagnet arranged vertically. The electromagnets in the magnetic field assemblies are arranged vertically and perpendicularly, or electromagnets of the same height in the magnetic field assemblies are arranged in the same direction and at the same angle, and the electromagnets of adjacent segments are arranged in opposite directions. The device further comprises the following one or more features:

14. A magnetic resonance magnetic separation method, characterized by, The device comprises a pre-selection bin, a wide-band magnetic separation device, a selected bin, and a selected remaining bin.

15. A thin layer magnetic separation device, characterized by The pre-selection bin is arranged above the input end of the wide-band magnetic separation device, and the selected bin and the selected remaining bin are arranged below the output end of the wide-band magnetic separation device. The wide-band magnetic separation device comprises a belt, an output end roller, an input end roller, a magnet, and a roller driving device. The discharge port of the pre-selection bin is arranged in a long strip shape along the width direction of the belt, and the discharge port of the pre-selection bin is inclined towards the output end of the wide-band magnetic separation device. The device further comprises the following one or more features: The device further comprises the following one or more features:

16. The thin-layer magnetic separation device of claim 15, wherein, ​ 17. Thin-layer magnetic separation device according to any of claims 15 or 16, characterized in that Two wideband magnetic separation devices are symmetrically arranged under the same pre-selection bin, the pre-selection bin is provided with two discharge outlets, and the two discharge outlets respectively discharge materials to the two wideband magnetic separation devices; preferably, a plurality of wideband magnetic separation devices are arranged in double or multiple layers, the pre-selection bin is provided with discharge outlets corresponding to the number of wideband magnetic separation devices, and each discharge outlet respectively discharges materials to each wideband magnetic separation device.

18. A thin layer magnetic separation method, characterized by, In the process of transporting the particles to be magnetically separated by the belt conveyor, the particles to be magnetically separated are distributed in a thin layer through the distribution of materials or the distribution of materials and vibration, and the strongly magnetized particles and the weakly magnetized particles are screened out under the action of the magnetic field when falling.

19. A direct steelmaking installation, characterized in that, The application relates to a DRI production and smelting system, which comprises a fluidized bed device, an electric furnace and a magnetic separation device, the magnetic separation device is used for magnetically separating the DRI powder reduced by the fluidized bed device, the high-grade DRI powder after magnetic separation is directly sent into the electric furnace for steelmaking, and the magnetic separation device is selected from any one of the split-diameter magnetic separation device of claim 1, the inclined-falling type magnetic separation device of claims 3-5, the chute type magnetic separation device of claims 8-10, the magnetic vibration type magnetic separation device of claim 13 and the thin-layer magnetic separation device of claims 15-17.

20. A direct steelmaking method using the direct steelmaking apparatus according to claim 19, characterized by, The DRI powder is prepared by the fluidized bed device, the DRI powder is magnetically separated by the magnetic separation device, and then is sent into the electric furnace for smelting.

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