Method and equipment system for full resource utilization of red mud

Abstract

This invention belongs to the field of solid waste treatment technology, specifically relating to a method for the resource-based disposal of red mud. Prepared raw materials and reducing agents are fed into a flash smelting furnace for smelting. The reducing agent, red mud, and solvent enter from the top of the main furnace and move downwards in a gaseous state, passing through a connecting flue above the molten pool into the bottom of the auxiliary furnace, then moving upwards and exiting from the top of the auxiliary furnace. The red mud is reduced and melted in the main furnace, and the sodium compounds in the red mud decompose into sodium oxide, which is removed in the tail gas. The auxiliary furnace is equipped with heat exchange tubes and a water spray device. The tail gas is cooled as it passes through the heat exchange tubes, and the sodium in the tail gas adheres to the heat exchange tubes. The sodium oxide adhering to the heat exchange tubes is washed by the spray water. The sodium oxide reacts with water to generate sodium hydroxide, which enters the spray water and then falls into a collection tank at the bottom of the auxiliary furnace. The sodium hydroxide solution is then sent to an alumina plant. This invention can recover iron and alkali, achieving full resource utilization of red mud.

Description

Technical Field

[0001] This invention belongs to the field of solid waste treatment technology, specifically relating to a method for the resource-based disposal of red mud. Background Technology

[0002] Red mud is a highly alkaline industrial waste generated during the production of alumina. Its production is positively correlated with the alumina output. For every ton of alumina produced, 1.0 to 1.8 tons of red mud are usually discharged.

[0003] The long-term storage of red mud not only wastes resources but also poses serious environmental risks and safety hazards, mainly in the following aspects: First, it causes highly alkaline pollution. The pH value of red mud is usually between 10 and 13, and can reach 14 in some extreme cases. Its leachate has an alkalinity as high as 26,348 mg / L. Long-term storage will lead to permanent alkalization of the surrounding soil, withering and death of vegetation, and pollution of groundwater, thus disrupting the regional ecosystem balance. Second, it causes heavy metal and toxic substance pollution. Red mud contains a variety of heavy metals and toxic substances such as chromium, lead, cadmium, and fluorides. After being leached by rainwater, it can easily enter the water and soil environment and harm human health through the food chain. Thirdly, there are safety hazards. Red mud stored using the wet method poses a risk of dam failure. Historically, there have been major safety accidents such as the leakage of red mud from the Hungarian Red Mud Storage. At the same time, the drying process of red mud is prone to generating dust, which pollutes the atmospheric environment and causes respiratory diseases in humans. Fourthly, there is a waste of resources. The iron content (calculated as iron oxide) in red mud is usually 14% to 45%. The iron content of red mud varies greatly depending on the production process and production area. Among them, the iron content of red mud produced by the Bayer process is relatively high, with some reaching more than 30%. The iron content of red mud produced by some high-quality raw materials can be as high as close to 54%. It is also rich in various valuable elements such as aluminum and titanium. Long-term storage leads to the idle and waste of these valuable resources.

[0004] Currently, my country has developed multiple technological approaches for the comprehensive utilization of red mud, mainly focusing on the following areas: First, iron extraction from red mud, using gravity separation, magnetic separation, and other processes to recover iron concentrate from red mud. This approach accounts for 55% to 70% of the existing red mud utilization, with an annual utilization exceeding 12 million tons. Second, utilization in the building materials sector, using red mud as a cement corrector, raw material for non-fired bricks, roadbed material, and cementitious material, but its content usually does not exceed 45%. Third, extraction of valuable elements, conducting research on the extraction of valuable elements such as aluminum, titanium, gallium, and scandium from red mud. Currently, this technology is mostly in the laboratory or pilot-scale testing stage and has not yet achieved large-scale industrial application. Fourth, ecological restoration and filling utilization, using red mud for scenarios such as mine backfilling, underground filling, and soil improvement.

[0005] Patent CN 110066923 A discloses a method for the comprehensive recovery of low-melting-point metals, iron, vanadium, and molten slag from red mud for cement production. The process steps are as follows: dehydrated and dried red mud is mixed with a solid carbonaceous reducing agent and a slag-forming agent, and directly injected into the center of the vortex of a high-temperature vortex-stirred melting and reduction furnace without sintering. The mixture is then vortex-stirred and melted at 1400-1600℃ for 10-60 minutes. Vanadium-containing water and molten slag are obtained by overflow and separation. The vanadium-containing molten iron is smelted with oxygen to separate vanadium slag and molten iron. Ferrochrome and ferromanganese are added to the molten iron and directly smelted into a cast iron-type wear-resistant alloy. Low-melting-point metals sodium, potassium, and gallium are collected and recovered in the flue gas dust collector during the reduction process. The composition of the molten slag is adjusted in the high-temperature vortex-stirred furnace to meet the requirements of cement, and then cooled, crushed, and ground to directly become cement clinker. Its disadvantages include the addition of slag-forming agent CaF2 during the smelting process. CaF2 is added at 10-30% of the CaO mass, resulting in a fluoride content in the slag exceeding 2%, which does not meet the requirements of GB / T203-2008 "Granulated Blast Furnace Slag for Cement". Furthermore, under high-calcium, high-molten-state conditions, sodium is solidified as stable salts such as sodium calcium silicate and sodium calcium aluminosilicate, with a very low volatilization rate. This affects the alkali recovery rate, and the high sodium content also prevents the slag from meeting quality requirements. Adjusting the composition in the furnace to reduce the proportion of sodium compounds and CaF2 significantly increases the procurement cost of the feedstock.

[0006] Patent CN120192096A discloses a method for the comprehensive treatment of red mud and its integration with the alumina production process for tiered energy utilization. Specifically, oxygen and steam, pulverized coal, and red mud powder are injected into the flash furnace from the top burner. The high-temperature heat and highly reducing gases generated by pulverized coal gasification directly melt and reduce Fe2O3 in the red mud to produce molten iron. The molten red mud and pulverized coal slag are then tempered and directly used to produce rock wool or other fibrous materials. Sodium oxide in the red mud is converted into sodium hydroxide for recycling. The waste heat from the high-temperature coal gas after smelting is recovered to produce steam for the alumina production evaporation section, coal gas for the alumina production roasting section, and roasting tail gas for red mud drying. This invention integrates red mud treatment and alumina production processes, re-engineers the process, and meets the energy needs of both processes through clean and efficient tiered utilization of coal, achieving energy conservation, emission reduction, and no secondary pollution. Its disadvantages are: under high-calcium, high-molten-state conditions, sodium is solidified as stable salts such as sodium calcium silicate and sodium calcium aluminosilicate, affecting volatilization efficiency. Especially since it flows downstream, the gas-solid reduction volatilization time is very short, generally 6-12 seconds. To achieve 70% sodium volatilization, at least 40 seconds are needed. Therefore, the actual sodium volatilization rate will be very low. This affects the alkali recovery efficiency, and the high sodium content also makes the basalt rock wool quality unacceptable, hindering the utilization of slag resources. Furthermore, after sodium oxide reduction in red mud, the sodium metal volatilizes at high temperatures and reacts with water vapor in the coal gas to generate sodium hydroxide for recycling. However, since the coal gas contains a large amount of dust, sodium hydroxide mixes with the dust, making the extraction of sodium hydroxide from the dust difficult and costly. Additionally, this technology suffers from tail gas condensation, leading to sodium oxide condensation and blockage, preventing normal and continuous operation. Finally, even if qualified basalt rock wool can be produced, the market capacity is far from absorbing the amount of red mud generated.

[0007] Patent CN 111410446 B discloses a method and production system for the resource-based treatment of solid waste from the aluminum industry using a rotary kiln. This method employs a sintering process to comprehensively recover alumina and sodium oxide from the aluminum industry's solid waste. Bayer process red mud is mixed with aluminum ash, limestone, soda ash, and anthracite, and then calcined to obtain clinker. The crude sodium aluminate solution obtained from the clinker leaching enters the settling section of the alumina production system, completing subsequent alumina production and alkali recycling, thereby achieving the goal of solid waste reuse and reducing alumina production costs. Its disadvantages include: firstly, iron in the red mud is not recovered; secondly, the amount of tailings after recovering alumina and sodium oxide from the aluminum industry's solid waste is large, meaning the amount of secondary red mud generated is larger than the amount of original red mud treated, resulting in more solid waste and greater difficulty in utilization.

[0008] In view of the problems of high cost, low utilization rate and secondary pollution of existing red mud comprehensive utilization technologies, there is an urgent need to develop a comprehensive, low-cost, and high-value red mud utilization technology. Summary of the Invention

[0011] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a one-step flash smelting method and system for the "full resource utilization" of red mud, so as to achieve low-cost preparation of molten iron, recovery of sodium, and preparation of high-performance concrete microcrystalline aggregates from slag, and truly realize "zero waste discharge and full utilization" of red mud.

[0012] The technical solution of this invention is as follows:

[0013] A method for the complete resource utilization of red mud includes the following steps:

[0014] S1 Raw material preparation and reducing agent preparation;

[0015] S2 The prepared raw materials and reducing agent are fed into the flash furnace for smelting; the flash furnace includes a main furnace with a reaction zone mainly for ironmaking, an auxiliary furnace mainly for sodium removal, and a molten pool with a connecting flue at the top; the bottoms of the main furnace and the auxiliary furnace are connected by a connecting flue.

[0016] The reducing agent, red mud, and solvent enter from the top of the main furnace and move downwards in a gaseous state. They then enter the bottom of the auxiliary furnace through the connecting flue above the molten pool, and move upwards to be discharged from the top of the auxiliary furnace. The red mud is reduced and melted in the main furnace. The silicon, aluminum, and titanium components in the red mud are calcified and transformed into calcium silicate, calcium aluminate, perovskite, and sodium compounds. The sodium compounds decompose into sodium oxide, which enters the tail gas.

[0017] The auxiliary furnace is equipped with heat exchange tubes and a water spray device. The exhaust gas is cooled as it passes through the heat exchange tubes, and the sodium in the exhaust gas is attached to the heat exchange tubes. There are two auxiliary furnaces, which are used alternately. One furnace is used to cool the exhaust gas and attach sodium oxides, while the other furnace is used to clean the sodium oxides attached to the heat exchange tubes with spray water. The sodium oxides react with water to generate sodium hydroxide, which enters the spray water and then falls into the collection tank at the bottom of the auxiliary furnace. The sodium hydroxide solution is recycled for spraying, and a portion of it is sent to the alumina plant.

[0018] S3 molten iron is discharged from the taphole, and slag is discharged from the slag outlet;

[0019] The molten iron from S4 enters the molten iron treatment system to produce industrial intermediate products such as block iron or molten iron for steelmaking.

[0020] The slag from S5 enters the slag treatment system to produce cement raw material water slag, slag powder or concrete raw material microcrystalline aggregate and other building materials.

[0021] The exhaust gas discharged from the auxiliary furnace by S6 is separated by a gas-solid separation device and enters the exhaust gas treatment system. The collected solid material enters the hot red mud chamber and is then sent to the main furnace through a hot red mud injection device.

[0022] Preferably, in step S1, the raw material preparation is red mud, which is dried in solvent until the water content is <5%; the solvent includes one or more of calcium-containing alkaline materials, dolomite, and silica; the ratio of CaO / (SiO2+TiO2) in the raw material is 1.05~1.2; and the dried raw material is sent to the flue gas duct of the hot red mud bin or the outlet of the auxiliary furnace.

[0023] Preferably, the gas-solid separation device includes a cyclone dust collector and a ceramic filter tube dust collector; after the gas-solid separation, the exhaust gas enters the CO2 removal device after waste heat recovery to remove CO2 from the exhaust gas. The gas with CO2 removed is recycled as reducing gas and is distributed into the main furnace from the top of the main furnace through the material distribution device. The material is evenly carried downward with the high-temperature reducing gas.

[0024] Preferably, the red mud includes bauxite leaching red mud; the composition includes: TFe: 10%–40%, Al2O3: 10%–25%, SiO2: 5%–15%, TiO2: 3%–10%, Na2O: 2%–10%, and a particle size of 100 mesh to 300 mesh; it also includes tailings from the recovery of aluminum and sodium from red mud, i.e., secondary red mud; or the above-mentioned red mud is beneficiated to select iron ore with a grade of 40%–65% for use in a flash furnace.

[0025] Preferably, the particle size is 200 mesh.

[0026] Preferably, the reducing agent preparation in S1 is the preparation of a reducing agent; the reducing agent is selected from pulverized coal, hydrogen, natural gas, or a combination thereof; when pulverized coal is used, an oxygen generation system and a pulverized coal preparation system are set up, and oxygen and pulverized coal are injected into the main furnace for combustion and heating while producing a reducing gas containing carbon monoxide and hydrogen; when hydrogen is used, a hydrogen heating device and a hydrogen preparation system are set up, and the hydrogen heating device is preferably a plasma heating system, and the heated hydrogen is sent into the main furnace; when natural gas is used, a natural gas reforming device needs to be set up.

[0027] Preferably, when coal is used as the reducing agent in whole or in part, pulverized coal is additionally injected into the lower part of the auxiliary furnace. The carbon in the pulverized coal reacts with the CO2 in the furnace gas to generate CO, which is used to improve the furnace gas and reduce the furnace gas temperature; or water vapor is injected at the same time to produce hydrogen through a water-gas reaction.

[0028] Preferably, oxygen is injected into the middle and lower parts of the main furnace for combustion and reheating, or reducing gas is externally heated and then injected for reheating, so that the temperature of the slag and iron entering the molten pool is 1450℃~1600℃.

[0029] Preferably, solid phase adhesion to the wall is prevented by abruptly expanding the diameter at a position close to but not entering the softening zone within the main furnace.

[0030] Preferably, at least one acceleration throat is provided in the lower part of the main furnace, so that the molten iron and slag accelerated when passing through the throat are rushed into the molten pool under the action of inertia, reducing the amount that escapes with the furnace gas and improving the gas-liquid separation efficiency.

[0031] Preferably, when coal is used as a reducing agent, the multi-point distributor at the top of the main furnace mixes in 3% to 15% coke particles at the same time as distributing red mud. The coke particles have a diameter of 5mm to 20mm, forming a coke layer on top of the molten pool slag layer, which supplements the final reduction of iron.

[0032] Preferably, the coke particles have a diameter of 10 mm.

[0033] Preferably, the slag treatment system can be used to control the cooling temperature and particle size of the slag discharged from the slag outlet by air blowing to obtain primary microcrystalline aggregate products; or it can be air-cooled to 1000-1220℃ and granulated before being fed into an electromagnetic temperature-controlled rotary kiln for deep processing; the electromagnetic temperature-controlled rotary kiln is divided into a front cooling section, a nucleation and heat preservation section, a heating section, a crystallization and heat preservation section and a rear cooling section along the material conveying direction. Except for the front and rear cooling sections, the nucleation and heat preservation section, the heating section and the crystallization and heat preservation section are all equipped with electromagnetic induction heating coils according to temperature requirements; and a suitable deep processing curve is selected according to the composition of the slag. The slag, which has been quenched into solid particles by air, is slowly cooled from 1000℃~1220℃ to 770℃~840℃ in a rotary kiln and held for 1h~3h to complete the formation of crystal nuclei. Then, it is rapidly heated to 950℃~1050℃ and held for 2h~4h to complete the growth of grains. Finally, it is slowly cooled to 600℃~500℃ to improve the performance of microcrystalline aggregate.

[0034] Preferably, the molten iron treatment system supplies the steelmaking process via tank cars or supplies the iron casting machine system with the intermediate product block iron.

[0035] Preferably, the reducing gas includes circulating gas heated by heat exchange tubes installed in the auxiliary furnace and then sent to the main furnace.

[0036] Preferably, before the red mud enters the flash smelting furnace, scandium is extracted by leaching, extraction, and back-extraction, or gallium, vanadium, lithium, and cobalt rare and high-valence metals are further extracted.

[0037] Preferably, a pre-alkali removal process is added beforehand; this process can be a normal pressure low-temperature calcification alkali removal process, a brine alkali removal process, or a combination of the two processes; pre-alkali removal or subsequent extraction of valuable metals such as titanium and scandium.

[0038] Preferably, a pre-alkali removal process is added beforehand; this process can be a normal pressure low-temperature calcification alkali removal process, a brine alkali removal process, or a combination of the two processes.

[0039] Furthermore, the feature is the addition of a pre-alkali removal process; this process can be an atmospheric pressure low-temperature calcification alkali removal process, a brine alkali removal process, or a combination of these two processes; pre-alkali removal or subsequent extraction of valuable metals such as titanium and scandium. The atmospheric pressure low-temperature calcification alkali removal process can be carried out at room temperature or heated to below 100°C. The heat source can utilize the waste heat from the flash furnace exhaust gas or the generated steam. Sodium removal chemical reaction formula:

[0040] Neutralization with free base: Na₂CO₃ + Ca(OH)₂ = CaCO₃↓ + 2NaOH

[0041] Lattice substitution of sodium structure (calcium nepheline / hydrated sodium aluminosilicate): Na₂O·Al₂O₃·2SiO₂·nH₂O + 3Ca(OH)₂ = 3CaO·Al₂O₃·2SiO₂·6H₂O (hydrated garnet) + 2NaOH

[0042] Process: Red mud slurry preparation → addition of lime slurry and stirring reaction for 1-3 hours → pressure filtration and washing → causticization of filtrate to recover alkali, which is then returned to the alumina plant if conditions permit, with a dealkali removal rate of 55%-75%. The dealkali removal residue is dried and supplied to the flash furnace.

[0043] Only a small amount of active aluminum dissolves into the mother liquor, while most of the aluminum is fixed in the hydrated garnet and can be recovered at the alumina plant after multiple rounds of concentration.

[0044] The brine method, also known as the calcium-magnesium salt ion exchange dealkalization method, involves the following chemical reaction for sodium removal:

[0045] 2NaAl(OH)4 + MgCl2 = Mg6Al2(CO3)(OH) 16 ·4H₂O (hydrotalcite)↓ + 2NaCl

[0046] Na2O·Al2O3·2SiO2 + CaCl2 + H2O = CaAl2Si2O8·H2O↓ + 2NaCl

[0047] Simultaneous neutralization by free base occurs: 2NaOH + MgCl₂ = Mg(OH)₂↓ + 2NaCl

[0048] Process: Red mud slurry is mixed with brine and stirred for 2-4 hours → thickening and sedimentation → multi-stage washing; the liquid phase is saline brine, and the solid phase is low-alkali red mud, with a sodium removal rate of 70%-82%. The brine is recycled at high concentration, and after sodium chloride enrichment, it is sold after cooling, concentration reduction, and precipitation. Salt field brine can be used near the sea. Where the area is far from the sea, brine can be prepared artificially.

[0049] A system for the full resource utilization of red mud includes a reducing agent supply device connected to a flash smelting furnace; a hot red mud injection device connected to a material distribution device and the main furnace of the flash smelting furnace; a secondary furnace outlet connected sequentially to a temperature-regulating cyclone dust collector, a temperature-regulating ceramic filter dust collector, a heat exchanger, and a CO2 removal device; the secondary furnace is equipped with heat exchange tubes for preheating reducing gas, a water spray device is installed at the top of the secondary furnace, and a liquid storage tank is installed at the bottom of the secondary furnace for cleaning sodium oxide adhering to the heat exchange tubes; the reducing agent supply device and the CO2 removal device are connected to the heat exchange tube inlet, and the heat exchange tube outlet is connected to the reducing agent inlet at the top of the main furnace; the temperature-regulating cyclone dust collector and the temperature-regulating ceramic filter dust collector are connected to the hot red mud bin; the red mud pretreatment system is connected to the hot red mud bin, the hot red mud injection device, the material distribution device, and the main furnace; and the flash smelting furnace is connected to both an iron treatment system and a slag treatment system.

[0050] Preferably, two auxiliary furnaces are provided and used alternately, one for discharging exhaust gas during production and the other for cleaning sodium oxide hanging on the heat exchange tubes; the liquid storage tank at the bottom of the auxiliary furnace is connected to the drain pump and the alumina plant.

[0051] Preferably, the red mud pretreatment system includes a wet red mud and solvent bin, a red mud or solvent drying device (rotary kiln, steam pipe rotary dryer), a red mud or solvent screening and crushing device, a conveying device, a dry red mud bin, and a dry red mud injection device, wherein the dry red mud injection device is connected to the dry red mud bin or the flue gas duct at the outlet of the auxiliary furnace.

[0052] Preferably, the flash smelting furnace includes a main furnace with a reaction zone primarily for ironmaking, an auxiliary furnace primarily for sodium removal, and a molten pool with a connecting flue at the top; the bottoms of the main furnace and the auxiliary furnace are connected by the connecting flue; the molten pool consists of a lower layer of molten iron, an upper layer of molten slag, and a carbon layer on top of the slag layer; the lower layer of the molten pool has an iron tap connected to the molten iron treatment system; the upper layer of the molten pool has a slag tap connected to the molten slag treatment system; the upper part of the main furnace has oxygen and pulverized coal injection ports (spray guns) connected to the oxygen supply system and the pulverized coal supply system, or has a hydrogen injection port connected to the hydrogen heating system; the top of the main furnace has a feed inlet connected to the material distribution system.

[0053] Preferably, the lower part of the auxiliary furnace is equipped with a pulverized coal injection gun to inject pulverized coal into the auxiliary furnace for gas quality improvement and temperature regulation, thereby reducing the CO2 content in the gas.

[0054] Preferably, at least one speed-up throat is provided in the lower part of the main furnace.

[0055] Preferably, the main furnace is equipped with a heat replenishment device in the middle and lower parts and above the throat; and a sudden diameter expansion structure is provided in the softening section of the main furnace.

[0056] Preferably, the slag treatment system can be a high-pressure air curtain granulation device; this device can be equipped with a rotating squirrel cage to enhance the crushing of slag, or it can simply be equipped with an array of multiple nozzles, or it can be a flat, continuous high-pressure air curtain nozzle; the slag treatment system can also be a high-pressure air curtain granulation device plus an electromagnetic temperature-regulating rotary kiln; the electromagnetic temperature-regulating rotary kiln is equipped with electromagnetic induction heating coils along the material conveying direction according to the temperature requirements of each section; the slag treatment system can also be a water quenching spray device; or it can be a combination of these.

[0057] Preferably, the material distribution device is a multi-point side-wind material distribution device; it includes a receiving bin, an upper valve, a weighing bin, a lower valve, a spraying bin, a material distribution pipe, and material distribution nozzles, which are connected sequentially from top to bottom; the weighing bin is supported on a weighing scale and has a pressure equalization supply and exhaust system; the spraying bin has a material level detector and a material carrier gas inlet; the upper valve and the lower valve are interlocked and alternately opened and closed according to the material level detector of the spraying bin and the weighing signal of the weighing bin; the material distribution nozzle consists of a side-blowing air channel and a material discharge channel, with the side-blowing air channel outlet and the material discharge outlet arranged close to each other at a certain angle; each side-blowing air channel is connected to the air supply system through a pipe, and the air supplied by the air supply system is preferably reducing gas; the material distribution nozzle is preferably made of industrial ceramic and is relatively evenly embedded in the furnace top of the main furnace; it is connected to the material distribution pipe in sections along the outside of each material distribution pipe or by a follow-up air pipe.

[0058] Preferably, the fabric spreading device is a centralized nozzle fabric spreader with a central channel for carrying reducing gas. The outlet of the central channel is an annular flat opening, which allows the reducing gas for fabric spreading to be sprayed radially horizontally or nearly horizontally to disperse the particulate material on the outer periphery. The channel for carrying particulate material is located in the outer ring, and the carrier gas is carbon dioxide or reducing gas.

[0059] Preferably, the feeding device is a centralized burner feeder. The innermost layer is an oxygen channel with an annular flat outlet, which allows oxygen to be radially sprayed horizontally or nearly horizontally to disperse particles on the outer periphery. The middle layer is an annular channel for pulverized coal, with carbon dioxide or reducing gas as the carrier gas. The outermost layer is an annular channel for pre-reduced red mud and solvent or coke particles, with carbon dioxide or reducing gas as the carrier gas. Alternatively, the middle and outermost layers can be combined.

[0060] Preferably, the material distribution device consists of multiple material spray guns that spray material evenly at different tangential angles from the upper side wall of the main furnace, either horizontally or nearly horizontally.

[0061] Preferably, before the red mud enters the flash smelting furnace, there is a mature leaching, purification, extraction, back-extraction, and solid-liquid separation process equipment for extracting scandium or further extracting high-value resources such as gallium, titanium, vanadium, and lithium, or further extracting other rare earth elements, and there is also a mature process equipment for washing and drying the formed leaching residue.

[0062] Preferably, the auxiliary furnace has an inverted U-shaped structure, and a spray device, heat exchange tube, and liquid collection tank are installed in the downward section of the inverted U-shape.

[0063] Preferably, a pre-alkali removal process equipment system is added beforehand; this equipment system can be a conventional equipment system for atmospheric pressure low-temperature calcification alkali removal process, a conventional equipment system for brine alkali removal process, or a combination of the two equipment systems; the pre-alkali removal equipment system is followed or connected to a conventional equipment system for extracting valuable metals such as titanium and scandium.

[0064] Preferably, a pre-alkali removal process equipment system is added beforehand; this equipment system can be a conventional equipment system for atmospheric pressure low-temperature calcification alkali removal process, a conventional equipment system for brine alkali removal process, or a combination of the two equipment systems.

[0065] Beneficial effects:

[0066] 1. Using the method of this invention, high-value processing of all red mud with three products (iron product, alkali product, and aggregate) in one step with the shortest process is achieved, even when the red mud has a low alkali content or when it is blended with ore. If the red mud has a high alkali content and blending with ore is inconvenient, high-value processing of all red mud can also be achieved through the two-step dealkali removal method of this invention.

[0067] 2. Since this method can achieve building material-grade dealkali treatment, the main component of red mud—aluminosilicates—can be transformed into medium- to high-value building material aggregates, replacing the current practice of large-scale mining of natural stone and river sand for aggregate production. The market capacity can fully support the consumption of red mud.

[0068] 3. Because dealkali removal and ironmaking are integrated, the process is the shortest, requiring less investment, less land, and lower operating costs.

[0069] 4. The main furnace co-current + liquid zone throat structure solves the problem of a large number of fine particles escaping with the wind in the co-current flash, and greatly improves the gas-solid separation efficiency;

[0070] 5. The abrupt expansion of the main furnace's softening zone solves the problem of flash furnace wall adhesion affecting production capacity.

[0071] 6. Thanks to the innovative electromagnetic temperature-controlled rotary kiln, precise temperature control for deep heat treatment, including simultaneous cooling, heat preservation, and heating, is achieved, enabling the slag to be used to prepare high-performance microcrystalline aggregates, transforming solid waste into high-grade building materials.

[0072] 7. The flash furnace for alkali removal solves the problem of alkali solidification and sticking, while simultaneously obtaining liquid or solid alkali products. It also enables the utilization of waste heat.

[0073] 8. Reduction gas is recycled, resulting in low energy consumption, low carbon emissions, and zero emissions.

[0074] 9. This invention is suitable for both future all-hydrogen smelting and transitional hydrocarbon mixed smelting, which is in line with the development trend.

[0075] 10. The method of the present invention can achieve a net profit of 90 to 130 yuan per ton of red mud. Attached Figure Description

[0076] Figure 1. Schematic diagram of an equipment system for a method of full resource utilization of red mud. Figure I

[0077] Figure 2. Schematic diagram of an equipment system for a method of full resource utilization of red mud. Figure II

[0078] Figure 3 AA Sectional View—Schematic Diagram of Auxiliary Furnace Layout

[0079] Legend markings

[0080] 1. Double-furnace flash smelting furnace, 101 main furnace, 102 auxiliary furnace, 1021 auxiliary furnace A, 1022 auxiliary furnace B, 103 molten pool, 104 taphole, 105 slag tap, 106 reheating device, 107 gas reforming device, 108 spraying device, 109 throat, steam lance, 110 heat exchange tube, 111 drain pump, 112 circulating gas valve I, 113 circulating gas valve II, 114 feed water valve I, 115 feed water valve II, 116 circulating gas valve III, 117 circulating gas valve IV, 118 tail gas valve I, 119 tail gas valve II, 120 collection tank, 2. Slag treatment system, 21 slag air cooling, 22 electromagnetic temperature-controlled rotary kiln, 23 microcrystalline aggregate, 24 slag water quenching, 25 water slag, 3. Red mud treatment system, 31 32 Wet red mud and solvent storage, 33 Red mud drying device, 34 Red mud transportation device, 35 Dry red mud storage, 36 Dry red mud blowing device, 37 Calcination rotary kiln, 38 Sodium aluminate leaching device, 4 Liquid-solid separation device, 5 Alkali washing tower, 6 CO2 removal device, 7 Temperature-controlled cyclone dust collector, 8 Hot red mud storage, 9 Hot red mud blowing device, 10 Temperature-controlled ceramic filter tube dust collector, 11 Alumina plant, 12 Oxygen supply device, 13 Pulverized coal supply device, 14 Waste heat boiler, 15 Fabrication device, 16 Hydrogen preparation system. Detailed Implementation

[0081] The present invention will be further described in detail below with reference to specific embodiments.

[0082] Example 1

[0083] Combination Figure 1 , Figure 3 Explanation

[0084] Using a flash furnace 1, red mud is processed into iron products, cement or concrete raw materials, and other building materials, including the following steps:

[0085] The red mud composition includes: TFe: 35%, Al2O3: 16.51%, SiO2: 12%, TiO2: 6%, Na2O: 6.5%, and a particle size of 200 mesh.

[0086] The wet red mud and solvent bin 31 of the red mud pretreatment system 3 feeds red mud and lime in a quantitative manner to the red mud drying device (rotary kiln) 32, where it is dried to a moisture content of less than 5%. Then, it is transported to the dry red mud bin 34 via the red mud transport device 33, and then conveyed to the hot red mud bin 7 via the dry red mud injection device 35. After adding lime to the red mud, its CaO / (SiO2+TiO2) ratio is 1.05~1.2. The hot red mud is sent to the material distribution device 14 above the main furnace via the hot red mud injection device 8 under the bin.

[0087] The coal powder preparation device 12 prepares coal powder into 200 μm particles; the oxygen supply device 11 supplies oxygen, and the coal powder and oxygen are injected from the top of the main furnace 101. The coal powder and oxygen are burned in the main furnace to produce reducing gas, which provides heat for smelting.

[0088] Red mud, lime, pulverized coal, and oxygen are fed into a double-furnace flash furnace 1 for smelting. The flash furnace 1 includes a main furnace 101, which is mainly for ironmaking, an auxiliary furnace 102, which is mainly for sodium recovery, and a molten pool 103 with a connecting flue at the top. The bottoms of the main furnace 101 and the auxiliary furnace 102 are connected by a connecting flue.

[0089] The reducing gas enters from the top of the main furnace 101 and flows downwards in a gaseous state. It then passes through the connecting flue above the molten pool 103 and enters the bottom of the auxiliary furnace 102. After that, it moves upwards and exits from the top of the auxiliary furnace 102, entering the gas-solid separation device for gas-solid separation. The auxiliary furnace 102 is equipped with heat exchange tubes 110 to reduce the tail gas temperature and preheat the reducing gas. The bottom of the auxiliary furnace 102 is equipped with a liquid collection tank 120 to collect and clean the sodium oxide deposits adhering to the heat exchange tubes 110.

[0090] Within the main furnace 101, the reduction reaction of iron oxides occurs and they melt. The gas-liquid mixture is accelerated through the throat 109 at the bottom of the main furnace 101, causing gas-liquid separation. The molten slag and iron enter the lower molten pool 103, first passing through the upper carbon layer, further reducing the unreduced iron oxides and increasing the iron yield. The slag and iron separate, with the molten iron settling to the bottom of the molten pool 103, and the slag layer above the iron layer. In the molten pool, the calcium oxide in the slag calcifies the silicon, aluminum, and titanium components in the slag, transforming them into calcium silicate, calcium aluminate, sodium aluminate, perovskite, and sodium oxide. The sodium oxide enters the tail gas in a gaseous state. The tail gas enters the auxiliary furnace 102 and passes through the heat exchange tubes 110, where it is cooled to approximately 900°C. The gaseous sodium oxide cools and adheres to the heat exchange tubes 110, and when a certain amount adheres, it is converted into a cleaning state.

[0091] Two auxiliary furnaces 102 are provided, namely auxiliary furnace I 1021 and auxiliary furnace II 1022. The two auxiliary furnaces work alternately. By switching the operation of the auxiliary furnaces through the valves, one auxiliary furnace is used to reduce the temperature of the exhaust gas, while the other auxiliary furnace is used to clean the sodium oxide adhering to the heat exchange tubes 110. The cleaned sodium oxide reacts with water to produce sodium hydroxide. The sodium hydroxide solution falls into the collection tank 120 at the bottom of the auxiliary furnace. A drain pump 121 is installed at the bottom of the collection tank 120. Part of the liquid discharged by the drain pump 121 enters the spray device 108 located at the top of the auxiliary furnace, and the other part is sent to the alumina plant 10 for recycling. During operation, water is replenished to the collection tank 120 at regular intervals.

[0092] The working procedure of the auxiliary furnace:

[0093] When auxiliary furnace I 1021 is used to reduce the tail gas temperature and auxiliary furnace II 1022 is used to clean heat exchange tube 110:

[0094] Open circulating air valve I (112), water supply valve II (115), circulating air valve III (116), and exhaust gas valve I (118).

[0095] Close the circulating gas valve II113, water supply valve I114, 117, circulating gas valve IV, and exhaust gas valve II119;

[0096] When auxiliary furnace I 1022 is used to reduce the tail gas temperature and auxiliary furnace II 1021 is used to clean heat exchange tube 110:

[0097] Close the recirculating air valve I 112, water supply valve II 115, 116, recirculating air valve III, and exhaust gas valve I.

[0098] Open the closed-loop gas valve II113, water supply valve I114, 117, closed-loop gas valve IV, and exhaust gas valve II119.

[0099] The exhaust gas discharged from the auxiliary furnace 102 enters the temperature-regulating cyclone dust collector 6 and the temperature-regulating ceramic filter tube dust collector 9 in sequence to purify the exhaust gas. The separated dust enters the hot red mud bin 7, and then is sent to the material distribution device 14 through the hot red mud injection system 8. The hot red mud is evenly distributed to the main furnace 101 through the material distribution device 14 and falls with the reducing gas. The purified exhaust gas is cooled by the waste heat boiler 13 and then enters the CO2 removal device 5 to remove CO2 from the exhaust gas. The CO2-removed exhaust gas is recycled as reducing gas. After being pressurized, it is passed into the heat exchange tube 110 of the auxiliary furnace for heating, and then injected from the top of the main furnace 101.

[0100] A supplementary heating device 106 is installed in the middle and lower part of the main furnace 101 to inject oxygen for combustion and supplementary heating, so that the temperature of slag and iron entering the molten pool 103 is 1450℃~1600℃.

[0101] Pulverized coal is injected into the lower part of auxiliary furnace 102. The carbon in the pulverized coal reacts with the CO2 in the furnace gas to produce CO, which is used for furnace gas upgrading and tail gas temperature reduction; or water vapor is injected at the same time to produce hydrogen through water-gas reaction.

[0102] An oxygen supply device 11 and a pulverized coal supply device 12 are provided. Oxygen and pulverized coal are injected into the main furnace 101 for combustion and heating, while simultaneously producing reducing gas containing carbon monoxide and hydrogen.

[0103] The multi-point feeding device 14 at the top of the main furnace 101 feeds in red mud and mixes in 3% to 15% coke particles with a diameter of 10mm. This coke particles form a coke layer on top of the slag layer in the molten pool 103, which supplements the final reduction of iron.

[0104] The molten iron is fed into the molten iron treatment system and cast into block iron products by a casting machine.

[0105] The slag discharged from the flash furnace 1 enters the slag treatment system 2. The slag is quenched into granules by the slag air-cooling device 21 and then sent to the electromagnetic temperature-controlled rotary kiln 22 for deep heat treatment. The electromagnetic temperature-controlled rotary kiln 22 is divided into a front cooling section, a nucleation and holding section, a heating section, a crystallization and holding section, and a rear cooling section along the material conveying direction. Except for the front and rear cooling sections, the nucleation and holding sections, heating sections, and crystallization and holding sections are all equipped with electromagnetic induction heating coils according to temperature requirements. A suitable deep heat treatment curve is selected according to the composition of the slag. Generally, the slag quenched into solid particles is slowly cooled from 1000-1220℃ to 770℃-840℃ in the rotary kiln, held for 1-3 hours to complete crystal nucleation, then rapidly heated to 950℃-1050℃, held for 2-4 hours to complete grain growth, and then slowly cooled to 600-500℃ to improve the performance of the microcrystalline aggregate 23.

[0106] Equipment system for the full resource utilization of red mud:

[0107] In the red mud pretreatment system 3, wet red mud and solvent silo 31 are quantitatively supplied with red mud and lime in proportion. The red mud and lime are fed together into the drying rotary kiln 33 for drying. The dried red mud and lime are transported to the dry red mud silo 35 by the red mud transport device 34. The dry red mud blowing device 36 under the dry red mud silo 35 sends the red mud and lime to the hot red mud silo 7. Then, the hot red mud blowing device 8 under the hot red mud silo 7 sends it to the material distribution device 14 at the top of the main furnace 101. The red mud and lime are evenly distributed to the main furnace 101 by the material distribution device 14.

[0108] Oxygen supply device 11 and pulverized coal supply device 12 are connected to the main furnace 101. Oxygen and pulverized coal are burned in the main furnace 101 to generate reducing gases such as CO, CO2, and H2 and release a large amount of heat. During the process of the reducing gas and red mud falling evenly and slowly in the main furnace, the iron oxides in the red mud are reduced and melted. A supplementary heating device 106 is set at the bottom of the main furnace 101 to inject oxygen or oxygen and pulverized coal into the main furnace. The heat generated by its combustion is used to supplement the heat of the smelting reaction. A throat 109 is set below the supplementary heating device 106. When the gas and liquid pass through the throat 109, they are accelerated, which improves the gas-liquid separation efficiency. The liquid enters the molten pool 103, and the gas (tail gas) enters the auxiliary furnace 102. A coal gas reforming device 107 is set at the bottom of the auxiliary furnace 102 to inject pulverized coal or water vapor into the auxiliary furnace. The high temperature of the tail gas is used to make the C in the pulverized coal react with the water vapor and CO2 in the tail gas to generate CO and H2.

[0109] Two auxiliary furnaces 102 are provided and used alternately. One is used for cooling the exhaust gas, and the other is used for cleaning the sodium oxide adhering to the heat exchange tubes. The auxiliary furnace is equipped with an upper spray device 108, and heat exchange tubes 110 are installed below the spray device 108. A liquid collection tank 120 is installed at the bottom of the auxiliary furnace 102.

[0110] The working procedure of the auxiliary furnace:

[0111] When auxiliary furnace I 1021 is used to reduce the tail gas temperature and auxiliary furnace II 1022 is used to clean heat exchange tube 110:

[0112] Open circulating air valve I (112), water supply valve II (115), circulating air valve III (116), and exhaust gas valve I (118).

[0113] Close the circulating gas valve II113, water supply valve I114, 117, circulating gas valve IV, and exhaust gas valve II119;

[0114] The exhaust gas discharged from the top of auxiliary furnace I 1021 sequentially enters the cyclone dust collector 6 and the temperature-regulating ceramic filter tube dust collector 9 for purification. The purified exhaust gas enters the waste heat boiler 13 for cooling, and then enters the CO2 removal device 5 to remove CO2 from the exhaust gas. The CO2-removed exhaust gas (as reducing gas) is recycled and enters the heat exchange tube 110 of the auxiliary furnace for heating. After heating, it is injected into the flash smelting furnace 1 from the top of the main furnace 101. The dust collected by the cyclone dust collector 6 and the temperature-regulating ceramic filter tube dust collector 9 is sent to the hot red mud bin 7.

[0115] When the auxiliary furnace 1022 starts the spray device 108, the sodium oxide hanging on the heat exchange tube 110 is washed by water. The sodium oxide turns into sodium hydroxide, dissolves in the water, and falls into the collection tank 120 at the bottom of the auxiliary furnace 102. A drain pump 121 is installed at the bottom of the collection tank 120. Part of the sodium hydroxide solution discharged by the drain pump 121 enters the spray device 108, and the other part is sent to the alumina plant 10 for recycling. Water is added to the collection tank 120 at regular intervals to maintain a stable liquid level in the collection tank 120.

[0116] When auxiliary furnace I 1022 is used to reduce the tail gas temperature and auxiliary furnace II 1021 is used to clean heat exchange tube 110:

[0117] Close the recirculating air valve I 112, water supply valve II 115, 116, recirculating air valve III, and exhaust gas valve I.

[0118] Open the closed-loop gas valve II113, water supply valve I114, 117, closed-loop gas valve IV, and exhaust gas valve II119.

[0119] The flash furnace 1 includes a main furnace 101 for ironmaking, an auxiliary furnace 102 for pre-reduction, and a molten pool 103 with a connecting flue at the top. The bottoms of the main furnace 101 and the auxiliary furnace 102 are connected by the connecting flue. The molten pool 103 consists of a lower layer of molten iron and an upper layer of molten slag. The lower layer of the molten pool 103 is provided with an iron tap 104, which is connected to the molten iron treatment system. The upper layer of the molten pool 103 is provided with a slag tap 105, which is connected to the slag treatment system 2. The upper part of the main furnace 101 is provided with an oxygen and pulverized coal injection port (spray gun), which is connected to an oxygen supply device 11 and a pulverized coal supply device 12. The top of the main furnace 101 is provided with a feed inlet, which is connected to a material distribution device 14. The lower part of the auxiliary furnace 102 is provided with a raw material inlet, which is connected to a red mud pretreatment system 3. The top of the auxiliary furnace 102 is provided with a gas-solid two-phase outlet, which is connected to the inlet of a gas-solid separation system (including a temperature-controlled cyclone dust collector 6 and a temperature-controlled ceramic filter tube dust collector 9).

[0120] The auxiliary furnace 102 is equipped with a gas reforming device 107 at the bottom, which injects pulverized coal into the auxiliary furnace 102 for gas reforming and temperature regulation, and reduces the CO2 content in the gas.

[0121] The gas-solid separation device consists of a temperature-controlled cyclone dust collector 6 and a temperature-controlled ceramic filter tube dust collector 9. The temperature-controlled cyclone dust collector 6 has a low-temperature gas-solid two-phase inlet tangentially arranged in the upper part of its ash hopper 98, which is consistent with the rotation direction of the gas-solid two-phase mixture that has entered. The inlet can also be cut downwards at a certain angle. The solid phase outlet of the temperature-controlled cyclone dust collector 6 is connected to the red mud covering device 14. The inlet of the temperature-controlled ceramic filter tube dust collector 9 is connected to the gas outlet of the temperature-controlled cyclone dust collector 6 and the waste heat boiler 13. The solid phase outlet is sequentially connected to the hot red mud bin 6, the hot red mud blowing device 7, and the covering device 14.

[0122] The middle and lower parts of the main furnace 101 and the upper part of the throat 109 are equipped with a heat replenishment device 106; the softening section of the main furnace 101 is equipped with a sudden diameter expansion structure.

[0123] The molten iron discharged from the flash furnace 1 is sent to the steel plant as raw material for steelmaking, or sent to the iron casting machine to be cast into commercial iron blocks.

[0124] The slag discharged from the flash furnace 1 is quenched into microcrystalline particles by the air-cooling device 21, and then sent to the electromagnetic rotary kiln 22 for heat treatment to improve the quality of the microcrystalline aggregate 23.

[0125] After being quenched by the slag water quenching device 24, the slag is then ground and separated into solid and liquid components by the slag-liquid separation device 25. The separated solid is used as a raw material for building materials, while the separated liquid contains sodium aluminate, which is then fed into the aluminum extraction device 26 to extract aluminum products.

[0126] Example 2

[0127] Combination Figure 1 , Figure 3 Explanation

[0128] Using a flash furnace 1, red mud is processed into iron products, cement or concrete raw materials, and other building materials, including the following steps:

[0129] The red mud composition includes: TFe: 35%, Al2O3: 16.51%, SiO2: 12%, TiO2: 6%, Na2O: 6.5%, and a particle size of 200 mesh.

[0130] The wet red mud and solvent bin 31 of the red mud pretreatment system 3 feeds red mud and lime in a quantitative manner to the red mud drying device (rotary kiln) 32 for drying until the moisture content is less than 5%. Then, it is transported to the dry red mud bin 34 via the red mud transport device 33, and then conveyed to the outlet pipe of the auxiliary furnace 102 via the dry red mud injection device 35. The red mud, along with the exhaust gas discharged from the auxiliary furnace 102, enters the temperature-controlled cyclone dust collector 6 and the temperature-controlled ceramic filter tube dust collector 9 in sequence to purify the exhaust gas. The separated dust enters the hot red mud bin 7. After adding lime to the red mud, its CaO / (SiO2+TiO2) ratio is 1.05~1.2. The hot red mud is sent to the material distribution device 14 above the main furnace through the hot red mud injection device 8 under the bin.

[0131] Hydrogen production device 12 produces hydrogen, which can be produced by electrolysis of water or by natural gas. The produced hydrogen is fed into heat exchange tube 110 of auxiliary furnace 102. After being heated, the hydrogen is sent from the top of main furnace 101 into flash furnace 1.

[0132] The coal powder preparation device 12 prepares coal powder into 200 μm particles; the oxygen supply device 11 supplies oxygen, and the coal powder and oxygen are injected from the top of the main furnace 101. The coal powder and oxygen are burned in the main furnace to provide heat for smelting.

[0133] Red mud, lime, pulverized coal, and oxygen are fed into a flash furnace 1 for smelting. The flash furnace 1 includes a main furnace 101, which is mainly used for ironmaking, an auxiliary furnace 102, which is mainly used for sodium recovery, and a molten pool 103 with a connecting flue at the top. The bottoms of the main furnace 101 and the auxiliary furnace 102 are connected by a connecting flue.

[0134] The reducing gas enters from the top of the main furnace 101 and flows downwards in a gaseous state. It then passes through the connecting flue above the molten pool 103 and enters the bottom of the auxiliary furnace 102. After that, it moves upwards and exits from the top of the auxiliary furnace 102, entering the gas-solid separation device for gas-solid separation. The auxiliary furnace 102 is equipped with heat exchange tubes 110 to reduce the tail gas temperature and preheat the reducing gas. The bottom of the auxiliary furnace 102 is equipped with a liquid collection tank 120 to collect and clean the sodium oxide deposits adhering to the heat exchange tubes 110.

[0135] Within the main furnace 101, the reduction reaction of iron oxides occurs and they melt. The gas-liquid mixture is accelerated through the throat 109 at the bottom of the main furnace 101, causing gas-liquid separation. The molten slag and iron enter the lower molten pool 103, first passing through the upper carbon layer, further reducing the unreduced iron oxides and increasing the iron yield. The slag and iron separate, with the molten iron settling to the bottom of the molten pool 103, and the slag layer above the iron layer. In the molten pool, the calcium oxide in the slag calcifies the silicon, aluminum, and titanium components in the slag, transforming them into calcium silicate, calcium aluminate, sodium aluminate, perovskite, and sodium oxide. The sodium oxide enters the tail gas in a gaseous state. The tail gas enters the auxiliary furnace 102 and passes through the heat exchange tubes 110, where it is cooled to approximately 900°C. The gaseous sodium oxide cools and adheres to the heat exchange tubes 110, and when a certain amount adheres, it is converted into a cleaning state.

[0136] Two auxiliary furnaces 102 are provided, namely auxiliary furnace I 1021 and auxiliary furnace II 1022. The two auxiliary furnaces work alternately. By switching the operation of the auxiliary furnaces through the valves, one auxiliary furnace is used to reduce the temperature of the exhaust gas, while the other auxiliary furnace is used to clean the sodium oxide adhering to the heat exchange tubes 110. The cleaned sodium oxide reacts with water to produce sodium hydroxide. The sodium hydroxide solution falls into the collection tank 120 at the bottom of the auxiliary furnace. A drain pump 121 is installed at the bottom of the collection tank 120. Part of the liquid discharged by the drain pump 121 enters the spray device 108 located at the top of the auxiliary furnace, and the other part is sent to the alumina plant 10 for recycling. During operation, water is replenished to the collection tank 120 at regular intervals.

[0137] The working procedure of the auxiliary furnace:

[0138] When auxiliary furnace I 1021 is used to reduce the tail gas temperature and auxiliary furnace II 1022 is used to clean heat exchange tube 110:

[0139] Open circulating air valve I (112), water supply valve II (115), circulating air valve III (116), and exhaust gas valve I (118).

[0140] Close the circulating gas valve II113, water supply valve I114, 117, circulating gas valve IV, and exhaust gas valve II119;

[0141] When auxiliary furnace I 1022 is used to reduce the tail gas temperature and auxiliary furnace II 1021 is used to clean heat exchange tube 110:

[0142] Close the recirculating air valve I 112, water supply valve II 115, 116, recirculating air valve III, and exhaust gas valve I.

[0143] Open the closed-loop gas valve II113, water supply valve I114, 117, closed-loop gas valve IV, and exhaust gas valve II119.

[0144] The exhaust gas discharged from the auxiliary furnace 102 enters the temperature-regulating cyclone dust collector 6 and the temperature-regulating ceramic filter tube dust collector 9 in sequence to purify the exhaust gas. The separated dust enters the hot red mud bin 7, and then is sent to the material distribution device 14 through the hot red mud injection system 8. The hot red mud is evenly distributed to the main furnace 101 through the material distribution device 14 and falls with the reducing gas. The purified exhaust gas is cooled by the waste heat boiler 13 and then enters the CO2 removal device 5 to remove CO2 from the exhaust gas. The CO2-removed exhaust gas is recycled as reducing gas. After being pressurized, it is passed into the heat exchange tube 110 of the auxiliary furnace for heating, and then injected from the top of the main furnace 101.

[0145] A supplementary heating device 106 is installed in the middle and lower part of the main furnace 101 to inject oxygen for combustion and supplementary heating, so that the temperature of slag and iron entering the molten pool 103 is 1450℃~1600℃.

[0146] Pulverized coal is injected into the lower part of auxiliary furnace 102. The carbon in the pulverized coal reacts with the CO2 in the furnace gas to produce CO, which is used for furnace gas upgrading and tail gas temperature reduction; or water vapor is injected at the same time to produce hydrogen through water-gas reaction.

[0147] The multi-point feeding device 14 at the top of the main furnace 101 feeds in red mud and mixes in 3% to 15% coke particles with a diameter of 10mm. This coke particles form a coke layer on top of the slag layer in the molten pool 103, which supplements the final reduction of iron.

[0148] The molten iron is fed into the molten iron treatment system and cast into block iron products by a casting machine.

[0149] The slag discharged from the flash furnace 1 enters the slag treatment system 2. The slag is quenched into granules by the slag air-cooling device 21 and then sent to the electromagnetic temperature-controlled rotary kiln 22 for deep heat treatment. The electromagnetic temperature-controlled rotary kiln 22 is divided into a front cooling section, a nucleation and holding section, a heating section, a crystallization and holding section, and a rear cooling section along the material conveying direction. Except for the front and rear cooling sections, the nucleation and holding sections, heating sections, and crystallization and holding sections are all equipped with electromagnetic induction heating coils according to temperature requirements. A suitable deep heat treatment curve is selected according to the composition of the slag. Generally, the slag quenched into solid particles is slowly cooled from 1000-1220℃ to 770℃-840℃ in the rotary kiln, held for 1-3 hours to complete crystal nucleation, then rapidly heated to 950℃-1050℃, held for 2-4 hours to complete grain growth, and then slowly cooled to 600-500℃ to improve the performance of the microcrystalline aggregate 23.

[0150] Equipment system for the full resource utilization of red mud:

[0151] In the red mud pretreatment system 3, wet red mud and solvent silo 31 are quantitatively supplied with red mud and lime in proportion. The red mud and lime are fed together into the drying rotary kiln 33 for drying. The dried red mud and lime are transported to the dry red mud silo 35 by the red mud transport device 34. The dry red mud blowing device 36 under the dry red mud silo 35 sends the red mud and lime to the flue gas pipe at the outlet of the auxiliary furnace 102. The red mud passes through the temperature-regulating cyclone dust collector 6 and the temperature-regulating ceramic filter tube dust collector 9 in sequence with the flue gas. The collected hot red mud enters the hot red mud silo 7, and then is sent to the material distribution device 14 above the main furnace 101 by the hot red mud blowing device 8 under the hot red mud silo 7. The red mud and lime are evenly distributed to the main furnace 101 by the material distribution device 14.

[0152] The hydrogen production device 14 is connected to the inlet pipe of the heat exchange tube 110 of the auxiliary furnace 102, and the hydrogen is injected from the top of the main furnace 101 after being heated.

[0153] Oxygen supply device 11 and pulverized coal supply device 12 are connected to the main furnace 101. Oxygen and pulverized coal are burned in the main furnace 101 to generate CO2, H2O, etc., which provide heat for the smelting reaction. During the process of the reducing gas and red mud falling evenly and slowly in the main furnace, the iron oxides in the red mud are reduced and melted. A supplementary heating device 106 is set at the bottom of the main furnace 101 to inject oxygen or oxygen and pulverized coal into the main furnace. The heat generated by its combustion is used to supplement the heat for the smelting reaction. A throat 109 is set below the supplementary heating device 106. When the gas and liquid pass through the throat 109, they are accelerated, which improves the gas-liquid separation efficiency. The liquid enters the molten pool 103, and the gas (tail gas) enters the auxiliary furnace 102. A coal gas reforming device 107 is set at the bottom of the auxiliary furnace 102 to inject pulverized coal or water vapor into the auxiliary furnace. The high temperature of the tail gas causes the C in the pulverized coal to react with the water vapor and CO2 in the tail gas to generate CO and H2.

[0154] Two auxiliary furnaces 102 are provided and used alternately. One is used for cooling the exhaust gas, and the other is used for cleaning the sodium oxide adhering to the heat exchange tubes. The auxiliary furnace is equipped with an upper spray device 108, and heat exchange tubes 110 are installed below the spray device 108. A liquid collection tank 120 is installed at the bottom of the auxiliary furnace 102.

[0155] The working procedure of the auxiliary furnace:

[0156] When auxiliary furnace I 1021 is used to reduce the tail gas temperature and auxiliary furnace II 1022 is used to clean heat exchange tube 110:

[0157] Open circulating air valve I (112), water supply valve II (115), circulating air valve III (116), and exhaust gas valve I (118).

[0158] Close the circulating gas valve II113, water supply valve I114, 117, circulating gas valve IV, and exhaust gas valve II119;

[0159] The exhaust gas discharged from the top of auxiliary furnace I 1021 sequentially enters the cyclone dust collector 6 and the temperature-regulating ceramic filter tube dust collector 9 for purification. The purified exhaust gas enters the waste heat boiler 13 for cooling, and then enters the CO2 removal device 5 to remove CO2 from the exhaust gas. The CO2-removed exhaust gas (as reducing gas) is recycled and enters the heat exchange tube 110 of the auxiliary furnace for heating. After heating, it is injected into the flash smelting furnace 1 from the top of the main furnace 101. The dust collected by the cyclone dust collector 6 and the temperature-regulating ceramic filter tube dust collector 9 is sent to the hot red mud bin 7.

[0160] When the auxiliary furnace 1022 starts the spray device 108, the sodium oxide hanging on the heat exchange tube 110 is washed by water. The sodium oxide turns into sodium hydroxide, dissolves in the water, and falls into the collection tank 120 at the bottom of the auxiliary furnace 102. A drain pump 121 is installed at the bottom of the collection tank 120. Part of the sodium hydroxide solution discharged by the drain pump 121 enters the spray device 108, and the other part is sent to the alumina plant 10 for recycling. Water is added to the collection tank 120 at regular intervals to maintain a stable liquid level in the collection tank 120.

[0161] When auxiliary furnace I 1022 is used to reduce the tail gas temperature and auxiliary furnace II 1021 is used to clean heat exchange tube 110:

[0162] Close the recirculating air valve I 112, water supply valve II 115, 116, recirculating air valve III, and exhaust gas valve I.

[0163] Open the closed-loop gas valve II113, water supply valve I114, 117, closed-loop gas valve IV, and exhaust gas valve II119.

[0164] The flash furnace 1 includes a main furnace 101 for ironmaking, an auxiliary furnace 102 for pre-reduction, and a molten pool 103 with a connecting flue at the top. The bottoms of the main furnace 101 and the auxiliary furnace 102 are connected by the connecting flue. The molten pool 103 consists of a lower layer of molten iron and an upper layer of molten slag. The lower layer of the molten pool 103 is provided with an iron tap 104, which is connected to the molten iron treatment system. The upper layer of the molten pool 103 is provided with a slag tap 105, which is connected to the slag treatment system 2. The upper part of the main furnace 101 is provided with an oxygen and pulverized coal injection port (spray gun), which is connected to an oxygen supply device 11 and a pulverized coal supply device 12. The top of the main furnace 101 is provided with a feed inlet, which is connected to a material distribution device 14. The lower part of the auxiliary furnace 102 is provided with a raw material inlet, which is connected to a red mud pretreatment system 3. The top of the auxiliary furnace 102 is provided with a gas-solid two-phase outlet, which is connected to the inlet of a gas-solid separation system (including a temperature-controlled cyclone dust collector 6 and a temperature-controlled ceramic filter tube dust collector 9).

[0165] The auxiliary furnace 102 is equipped with a gas reforming device 107 at the bottom, which injects pulverized coal into the auxiliary furnace 102 for gas reforming and temperature regulation, and reduces the CO2 content in the gas.

[0166] The gas-solid separation device consists of a temperature-controlled cyclone dust collector 6 and a temperature-controlled ceramic filter tube dust collector 9. The temperature-controlled cyclone dust collector 6 has a low-temperature gas-solid two-phase inlet tangentially arranged in the upper part of its ash hopper 98, which is consistent with the rotation direction of the gas-solid two-phase mixture that has entered. The inlet can also be cut downwards at a certain angle. The solid phase outlet of the temperature-controlled cyclone dust collector 6 is connected to the red mud covering device 14. The inlet of the temperature-controlled ceramic filter tube dust collector 9 is connected to the gas outlet of the temperature-controlled cyclone dust collector 6 and the waste heat boiler 13. The solid phase outlet is sequentially connected to the hot red mud bin 6, the hot red mud blowing device 7, and the covering device 14.

[0167] The middle and lower parts of the main furnace 101 and the upper part of the throat 109 are equipped with a heat replenishment device 106; the softening section of the main furnace 101 is equipped with a sudden diameter expansion structure.

[0168] The molten iron discharged from the flash furnace 1 is sent to the steel plant as raw material for steelmaking, or sent to the iron casting machine to be cast into commercial iron blocks.

[0169] After the molten slag is quenched by the molten slag water quenching device 24, the quenched slag 25 is used as a building material raw material.

[0170] Example 3

[0171] The difference from Example 1 is as follows:

[0172] There is one auxiliary furnace 102. The auxiliary furnace has an inverted U-shaped structure. The downward section of the U-shape is equipped with a spray device, heat exchange tubes, and a liquid collection tank.

[0173] Example 4

[0174] The difference from Example 1 is as follows:

[0175] The material distribution device 14 is a multi-point side-wind material distribution device; the hot red mud bin 6 is connected in sequence with the hot red mud injection device 7, the material distribution device 14, and the main furnace 101; the hot red mud injection device 7 is equipped with a weighing element and a pressure equalization supply and exhaust system; the injection tank of the hot red mud injection device 7 is equipped with a material level detector and a material carrier gas inlet; the upper valve and the lower valve are interlocked and alternately opened and closed according to the material level detector of the injection bin and the weighing signal of the weighing bin; the material distribution nozzle consists of a side blowing channel and a material discharge channel, and the outlet of the side blowing channel and the material discharge outlet are arranged close to each other at a certain angle; each side blowing channel is connected to the air supply system through a pipe, and the air supplied by the air supply system is preferably reducing gas; the material distribution nozzle is preferably made of industrial ceramic and is relatively evenly embedded in the furnace top of the main furnace 101; it is connected to the material distribution pipe in sections along the outside of each material distribution pipe or by a tracing air pipe.

[0176] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A method for the full resource utilization of red mud, characterized in that, Includes the following steps: S1 Raw material preparation and reducing agent preparation; S2 The prepared raw materials and reducing agent are fed into the flash furnace for smelting; the flash furnace includes a main furnace with a reaction zone mainly for ironmaking, an auxiliary furnace mainly for sodium removal, and a molten pool with a connecting flue at the top; the bottoms of the main furnace and the auxiliary furnace are connected by a connecting flue. The reducing agent, red mud, and solvent enter from the top of the main furnace and move downwards in a gaseous state. They then enter the bottom of the auxiliary furnace through the connecting flue above the molten pool, and move upwards to be discharged from the top of the auxiliary furnace. In the main furnace, the red mud is reduced and melted. The silicon, aluminum, and titanium components in the red mud are calcified and transformed into calcium silicate, calcium aluminate, perovskite, and sodium compounds. The sodium compounds decompose into sodium oxide, which enters the tail gas. The auxiliary furnace is equipped with heat exchange tubes and a water spray device. The exhaust gas is cooled as it passes through the heat exchange tubes, and the sodium in the exhaust gas is attached to the heat exchange tubes. There are two auxiliary furnaces, which are used alternately. One furnace is used to cool the exhaust gas and attach sodium oxides, while the other furnace is used to clean the sodium oxides attached to the heat exchange tubes with spray water. The sodium oxides react with water to generate sodium hydroxide, which enters the spray water and then falls into the collection tank at the bottom of the auxiliary furnace. The sodium hydroxide solution is recycled for spraying, and a portion of it is sent to the alumina plant. S3 molten iron is discharged from the taphole, and slag is discharged from the slag outlet; The molten iron from S4 enters the molten iron treatment system to produce industrial intermediate products such as block iron or molten iron for steelmaking. The slag from S5 enters the slag treatment system to produce cement raw material water slag, slag powder or concrete raw material microcrystalline aggregate and other building materials. The exhaust gas discharged from the auxiliary furnace by S6 is separated by a gas-solid separation device and enters the exhaust gas treatment system. The collected solid material enters the hot red mud chamber and is then sent to the main furnace through a hot red mud injection device.

2. The method for the full resource utilization of red mud as described in claim 1, characterized in that, In step S1, the raw material preparation is red mud, which is dried in solvent until the water content is <5%; the solvent includes one or more of calcium-containing alkaline materials, dolomite, and silica; the ratio of CaO / (SiO2+TiO2) in the raw material is 1.05~1.2; the dried raw material is sent to the hot red mud bin or the flue gas duct at the outlet of the auxiliary furnace.

3. The method for the full resource utilization of red mud as described in claim 1, characterized in that, The gas-solid separation device includes a cyclone dust collector and a ceramic filter tube dust collector. After the gas-solid separation, the exhaust gas is recycled after waste heat recovery and enters the CO2 removal device to remove CO2 from the exhaust gas. The gas with CO2 removed is recycled as reducing gas and is distributed into the main furnace from the top of the main furnace through the material distribution device. The material is evenly carried downward with the high-temperature reducing gas.

4. The method for the full resource utilization of red mud as described in claim 1, characterized in that, The red mud includes bauxite leaching red mud; its composition includes: TFe: 10%–40%, Al2O3: 10%–25%, SiO2: 5%–15%, TiO2: 3%–10%, Na2O: 2%–10%, and a particle size of 100 to 300 mesh; it also includes tailings from the recovery of aluminum and sodium from red mud, i.e., secondary red mud; or the above-mentioned red mud beneficiation to select iron ore with a grade of 40%–65% for use in a flash furnace.

5. A method for the full resource utilization of red mud as described in claim 3, characterized in that, The particle size is 200 mesh.

6. The method for the full resource utilization of red mud as described in claim 1, characterized in that, The reducing agent preparation in S1 refers to the preparation of a reducing agent; the reducing agent is selected from pulverized coal, hydrogen, natural gas, or a combination thereof; when pulverized coal is used, an oxygen production system and a pulverized coal preparation system are set up, and oxygen and pulverized coal are injected into the main furnace for combustion and heating while producing a reducing gas containing carbon monoxide and hydrogen; when hydrogen is used, a hydrogen heating device and a hydrogen preparation system are set up, with plasma heating system being preferred for the hydrogen heating device, and the heated hydrogen is then sent to the main furnace; when natural gas is used, a natural gas reforming device needs to be set up.

7. A method for the full resource utilization of red mud as described in claim 1, characterized in that, When coal is used as a reducing agent in whole or in part, pulverized coal is injected into the lower part of the auxiliary furnace. The carbon in the pulverized coal reacts with the CO2 in the furnace gas to generate CO, which is used to improve the furnace gas and reduce the furnace gas temperature; or water vapor is injected at the same time to produce hydrogen through water-gas reaction.

8. A method for the full resource utilization of red mud as described in claim 1, characterized in that, Oxygen is injected into the middle and lower parts of the main furnace for combustion and supplemental heating, or reducing gas is externally heated and then injected for supplemental heating, so that the temperature of the slag and iron entering the molten pool is 1450℃~1600℃.

9. A method for the full resource utilization of red mud as described in claim 1, characterized in that, Solid phase adhesion to the wall is prevented by abruptly expanding the diameter at a position close to but not entering the softening zone within the main furnace.

10. A method for the full resource utilization of red mud as described in claim 1, characterized in that, At least one acceleration throat is installed in the lower part of the main furnace so that the molten iron and slag accelerated when passing through the throat are rushed into the molten pool under the action of inertia, reducing the amount that escapes with the furnace gas and improving the gas-liquid separation efficiency.

11. A method for the full resource utilization of red mud as described in claim 1, characterized in that, When coal is used as a reducing agent, the multi-point distributor on the top of the main furnace mixes in 3% to 15% coke particles at the same time as distributing red mud. The coke particles have a diameter of 5mm to 20mm and form a coke layer on top of the molten pool slag layer, which supplements the final reduction of iron.

12. A method for the full resource utilization of red mud as described in claim 11, characterized in that, The coke particles have a diameter of 10 mm.

13. The method for the full resource utilization of red mud as described in claim 1, characterized in that, The slag treatment system can be used to cool the slag discharged from the slag outlet by controlling the cooling temperature and particle size with air to obtain primary microcrystalline aggregate products; or it can be air-cooled to 1000-1220℃ and granulated before being fed into an electromagnetic temperature-controlled rotary kiln for deep processing. The electromagnetic temperature-controlled rotary kiln is divided into a front cooling section, a nucleation and heat preservation section, a heating section, a crystallization and heat preservation section, and a rear cooling section along the material conveying direction. Except for the front and rear cooling sections, the nucleation and heat preservation section, the heating section, and the crystallization and heat preservation section are all equipped with electromagnetic induction heating coils according to temperature requirements. A suitable deep processing curve is selected according to the composition of the slag. The slag, which has been quenched into solid particles by air, is slowly cooled from 1000℃~1220℃ to 770℃~840℃ in a rotary kiln and held for 1h~3h to complete the formation of crystal nuclei. Then, it is rapidly heated to 950℃~1050℃ and held for 2h~4h to complete the growth of grains. Finally, it is slowly cooled to 600℃~500℃ to improve the performance of microcrystalline aggregate.

14. A method for the full resource utilization of red mud as described in claim 1, characterized in that, The molten iron treatment system supplies the steelmaking process via tank trucks or supplies the iron casting machine system with block iron as an intermediate product.

15. A method for the full resource utilization of red mud as described in claim 6, characterized in that, The reducing gas consists of circulating gas heated by heat exchange tubes installed in the auxiliary furnace and then sent to the main furnace.

16. A method for the full resource utilization of red mud as described in any one of claims 2 to 15, characterized in that, Before the red mud enters the flash smelting furnace, scandium is extracted through leaching, extraction, and back-extraction, or further rare and high-priced metals such as gallium, vanadium, lithium, and cobalt are extracted.

17. A method for the full resource utilization of red mud as described in claims 2-15, characterized in that, A pre-alkali removal process is added beforehand; this process can be a normal pressure low-temperature calcification alkali removal process, a brine alkali removal process, or a combination of the two processes; pre-alkali removal or subsequent extraction of valuable metals such as titanium and scandium.

18. A method for the full resource utilization of red mud as described in claim 17, characterized in that, A pre-alkali removal process is added beforehand; this process can be a normal pressure low-temperature calcification alkali removal process, a brine alkali removal process, or a combination of the two processes.

19. A device system for the complete resource utilization of red mud, characterized in that, The reducing agent supply device is connected to the flash smelting furnace; the hot red mud injection device is connected to the charging device and the main furnace of the flash smelting furnace; the gas outlet of the auxiliary furnace is sequentially connected to the temperature-regulating cyclone dust collector, the temperature-regulating ceramic filter tube dust collector, the heat exchanger, and the CO2 removal device; the auxiliary furnace is equipped with heat exchange tubes for preheating the reducing gas, a water spray device is installed at the top of the auxiliary furnace, and a liquid storage tank is installed at the bottom of the auxiliary furnace for cleaning the sodium oxide hanging on the heat exchange tubes; the reducing agent supply device and the CO2 removal device are connected to the heat exchange tube inlet, and the heat exchange tube outlet is connected to the reducing agent inlet at the top of the main furnace; the temperature-regulating cyclone dust collector and the temperature-regulating ceramic filter tube dust collector are connected to the hot red mud bin, and the red mud pretreatment system is connected to the hot red mud bin, the hot red mud injection device, the charging device, and the main furnace; the flash smelting furnace is connected to the molten iron treatment system and the slag treatment system respectively.

20. The equipment system for the full resource utilization of red mud as described in claim 19, characterized in that, Two auxiliary furnaces are provided and used alternately. One is used to discharge exhaust gas during production, and the other is used to clean the sodium oxide hanging on the heat exchange tubes. The liquid storage tank at the bottom of the auxiliary furnace is connected to the drain pump and the alumina plant.

21. The equipment system for the full resource utilization of red mud as described in claim 19, characterized in that, The red mud pretreatment system includes, in sequence, a wet red mud and solvent bin, a red mud or solvent drying device (rotary kiln, steam pipe rotary dryer), a red mud or solvent screening and crushing device, a conveying device, a dry red mud bin, and a dry red mud injection device, wherein the dry red mud injection device is connected to the dry red mud bin or the flue gas duct at the outlet of the auxiliary furnace.

22. The equipment system for the full resource utilization of red mud as described in claim 19, characterized in that, The flash smelting furnace includes a main furnace with a reaction zone primarily for ironmaking, an auxiliary furnace primarily for sodium removal, and a molten pool with a connecting flue at the top; the bottoms of the main furnace and the auxiliary furnace are connected by the connecting flue; the molten pool consists of a lower layer of molten iron, an upper layer of molten slag, and a carbon layer on top of the slag layer; the lower layer of the molten pool has an iron tap connected to the molten iron treatment system; the upper layer of the molten pool has a slag tap connected to the molten slag treatment system; the upper part of the main furnace has oxygen and pulverized coal injection ports (spray guns) connected to the oxygen supply system and the pulverized coal supply system, or a hydrogen injection port connected to the hydrogen heating system; the top of the main furnace has a feed inlet connected to the charging system.

23. The equipment system for the full resource utilization of red mud as described in claim 19, characterized in that, The lower part of the auxiliary furnace is equipped with a pulverized coal injection gun to inject pulverized coal into the auxiliary furnace for gas quality improvement and temperature regulation, thereby reducing the CO2 content in the gas.

24. The equipment system for the full resource utilization of red mud as described in claim 19, characterized in that, At least one speed-up throat is provided in the lower part of the main furnace.

25. The equipment system for the full resource utilization of red mud as described in claim 19, characterized in that, The main furnace is equipped with a heating device in the middle and lower parts and above the throat; the main furnace has a sudden diameter expansion structure in the softening section.

26. The equipment system for the full resource utilization of red mud as described in claim 19, characterized in that, The slag treatment system can be a high-pressure air curtain granulation device; this device can be equipped with a rotating squirrel cage to enhance the crushing of slag, or it can simply be equipped with an array of multiple nozzles, or it can be a flat, continuous high-pressure air curtain nozzle; the slag treatment system can also be a high-pressure air curtain granulation device plus an electromagnetic temperature-regulating rotary kiln; the electromagnetic temperature-regulating rotary kiln is equipped with electromagnetic induction heating coils along the material conveying direction according to the temperature requirements of each section; the slag treatment system can also be a water quenching spray device; or it can be a combination of these.

27. The equipment system for the full resource utilization of red mud as described in claim 19, characterized in that, The material distribution device is a multi-point side-wind material distribution device; it includes a receiving bin, an upper valve, a weighing bin, a lower valve, a spraying bin, a material distribution pipe, and material distribution nozzles, which are connected sequentially from top to bottom; the weighing bin is supported on a weighing scale and is equipped with a pressure equalization supply and exhaust system; the spraying bin has a material level detector and a material carrier gas inlet; the upper valve and the lower valve are interlocked and alternately opened and closed according to the material level detector of the spraying bin and the weighing signal of the weighing bin; the material distribution nozzle consists of a side-blowing air channel and a material discharge channel, with the side-blowing air channel outlet and the material discharge outlet arranged close to each other at a certain angle; each side-blowing air channel is connected to the air supply system through a pipe, and the air supplied by the air supply system is preferably reducing gas; the material distribution nozzle is preferably made of industrial ceramic and is relatively evenly embedded in the top of the main furnace; it is connected to the material distribution pipe in sections along the outside of each material distribution pipe or by a follow-up air pipe.

28. The equipment system for the full resource utilization of red mud as described in claim 19, characterized in that, The fabric distribution device is a centralized nozzle fabric distributor with a central channel for carrying reducing gas. The outlet of the central channel is an annular flat opening, which allows the reducing gas used for fabric distribution to be sprayed radially or nearly horizontally to disperse the particulate material on the outer periphery. The channel for carrying particulate material is located in the outer ring, and the carrier gas is carbon dioxide or reducing gas.

29. The equipment system for the full resource utilization of red mud as described in claim 19, characterized in that, The feeding device is a centralized burner feeder. The innermost layer is the oxygen channel, and the outlet of the channel is an annular flat opening, which allows oxygen to be sprayed radially horizontally or nearly horizontally to disperse the particles on the outer periphery. The middle section is a ring-shaped channel for pulverized coal, with carbon dioxide or reducing gas as the carrier gas. The outermost layer is an annular channel for pre-reduced red mud and solvent or coke particles, with carbon dioxide or reducing gas as the carrier gas; the middle and outermost layers can also be combined.

30. The equipment system for the full resource utilization of red mud as described in claim 19, characterized in that, The material distribution device consists of multiple material spray guns that spray material evenly at different tangential angles from the upper side wall of the main furnace, either horizontally or nearly horizontally.

31. The equipment system for the full resource utilization of red mud as described in claim 19, characterized in that, The auxiliary furnace has an inverted U-shaped structure, and a spray device, heat exchange tube, and liquid collection tank are installed in the downward section of the inverted U-shape.

32. A device system for the full resource utilization of red mud as described in any one of claims 20-31, characterized in that, Before the red mud enters the flash smelting furnace, there are mature leaching, purification, extraction, back-extraction, and solid-liquid separation process equipment for extracting scandium or further extracting high-value resources such as gallium, titanium, vanadium, and lithium, or further extracting other rare earth elements. There are also mature process equipment for washing and drying the leaching residue formed.

33. The equipment system for the full resource utilization of red mud as described in claims 20-31, characterized in that, A pre-alkali removal process equipment system is added beforehand; this equipment system can be a conventional equipment system for atmospheric pressure low-temperature calcification alkali removal process, a conventional equipment system for brine alkali removal process, or a combination of the two equipment systems; the conventional equipment system for extracting valuable metals such as titanium and scandium is added after or following the pre-alkali removal equipment system.

34. The equipment system for the full resource utilization of red mud as described in claim 33, characterized in that, An additional pre-alkali removal process equipment system is added; this process equipment system can be a conventional equipment system for atmospheric pressure low temperature calcification alkali removal process, a conventional equipment system for brine alkali removal process, or a combination of the two equipment systems.

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