An aluminum dross treatment system

Abstract

The application discloses an aluminum ash residue treatment system, which comprises an aluminum ash residue pretreatment unit and a resource recovery unit. The aluminum ash residue pretreatment unit comprises an aluminum ash residue bin, a crusher, a ball mill, a first screening mechanism and a molten aluminum furnace which are sequentially and serially arranged. The resource recovery unit comprises an aluminum ash bin, a residue-aluminum catalytic separation mechanism, a second screening mechanism, a reaction mechanism, a flocculation and sedimentation mechanism and a filtering and drying mechanism which are sequentially and serially arranged. The application combines the dry pretreatment unit with the wet resource recovery unit, improves the recovery effect and efficiency of aluminum resources in the aluminum ash residue, greatly reduces or even avoids the discharge of secondary pollutants, and realizes efficient and green recovery of the aluminum ash residue. The application has the advantages of good quality and high strength of the recovered product, high economic benefits, simple system structure, easy operation, environmental friendliness, low operation cost and the like.

Description

Technical Field

[0001] This invention relates to equipment for treating aluminum ash slag, specifically to an aluminum ash slag treatment system, belonging to the field of aluminum ash slag resource utilization technology. Background Technology

[0002] my country's aluminum smelting and processing industry is massive, with primary aluminum production reaching 35 million tons, processed aluminum products reaching 41 million tons, and recycled aluminum production reaching 6 million tons in 2019. The aluminum industry is a typical high-energy-consuming and high-polluting industry, generating a large amount of solid waste, especially hazardous waste, during production and processing, which hinders the green development of the aluminum industry. Aluminum ash slag is a solid waste generated during primary aluminum smelting, aluminum alloy processing, and aluminum recycling. Aluminum ash slag contains a high amount of aluminum, alumina, and chloride salts, as well as small amounts of fluorides, silicon, and other heavy metals. Furthermore, due to differences in the origin of the ore, the composition of aluminum ash slag obtained using the same smelting process varies considerably. In addition, during the high-temperature smelting process, liquid aluminum reacts with nitrogen in the air to form aluminum nitride. Fine aluminum nitride is black. After cooling, the aluminum nitride (AlN) in the aluminum ash easily reacts with water in the air to produce ammonia. Therefore, the aluminum ash slag has a foul odor, is black powdery, and contains a lot of large aluminum flakes (granules) and salts. It may contain trace amounts of Al4C3 and Al2S3.

[0003] The fluorides, heavy metals, and other toxic substances contained in aluminum ash slag also pose significant environmental hazards. Improper disposal can lead to soil, groundwater, and air pollution. Fluoride pollution can affect plant photosynthesis and respiration, and damage human bones, teeth, and the central nervous system.

[0004] Currently, most aluminum ash slag treatment involves building stockpiles, which not only wastes land resources but also causes environmental pollution. Therefore, it is necessary to develop more efficient aluminum ash slag treatment technologies. Summary of the Invention

[0005] To address the problems of serious land resource waste and environmental pollution caused by unsatisfactory removal of fluorides and heavy metals in existing aluminum ash slag treatment technologies, this invention provides an aluminum ash slag treatment system. This system, by combining a dry pretreatment unit with a wet resource recovery unit, greatly improves the recovery effect and efficiency of aluminum resources in aluminum ash slag, while also significantly reducing or even avoiding the discharge of secondary pollutants. The system has a simple structure, is easy to operate, has high aluminum ash slag resource treatment efficiency, and produces high-quality products with excellent recovery rates.

[0006] To achieve the above-mentioned technical objectives, the technical solution adopted by the present invention is as follows:

[0007] An aluminum ash slag treatment system includes an aluminum ash slag pretreatment unit and a resource recovery unit. The aluminum ash slag pretreatment unit includes an aluminum ash slag silo, a crusher, a ball mill, a first screening mechanism, and an aluminum melting furnace, arranged in series. The resource recovery unit includes an aluminum ash silo, a slag-aluminum catalytic separation mechanism, a second screening mechanism, a reaction mechanism, a flocculation and sedimentation mechanism, and a filtration and drying mechanism, arranged in series. The oversize discharge port of the first screening mechanism is connected to the inlet of the aluminum melting furnace via a first conveying mechanism, and the undersize discharge port of the first screening mechanism is connected to the inlet of the aluminum ash silo via a second conveying mechanism. The oversize discharge port of the second screening mechanism is connected to the inlet of the aluminum melting furnace via a third conveying mechanism, and the undersize discharge port of the second screening mechanism is connected to the inlet of the reaction mechanism via a fourth conveying mechanism.

[0008] Preferably, the first screening mechanism includes a vibrating screen and a drum screen connected in series. The oversize discharge port of the vibrating screen is connected to the inlet of the aluminum melting furnace via a first conveying mechanism, and the undersize discharge port of the vibrating screen is connected to the inlet of the drum screen via a fifth conveying mechanism. The oversize discharge port of the drum screen is connected to the inlet of the aluminum melting furnace via a sixth conveying mechanism, and the undersize discharge port of the drum screen is connected to the inlet of the aluminum ash silo via a second conveying mechanism.

[0009] Preferably, the screen aperture of the vibrating screen is 5-10 mm. The screen aperture of the drum screen is 1-3 mm.

[0010] Preferably, the aluminum ash slag pretreatment unit further includes a dry belt dust collector and an aluminum melting dust removal device. The air inlet of the dry belt dust collector is independently connected via multiple suction pipes and multiple suction hoods to the feed and / or discharge ends of the aluminum ash slag silo, the crusher, the ball mill, the vibrating screen, the drum screen, and the aluminum ash silo. The air inlet of the aluminum melting dust removal device is connected to the exhaust port of the aluminum melting furnace via suction pipes and suction hoods. The exhaust ports of both the dry belt dust collector and the aluminum melting dust removal device are connected to the chimney via exhaust pipes.

[0011] Preferably, both the aluminum ash slag silo and the aluminum ash silo's discharge port are equipped with vibration anti-clogging devices. A vibrating feeder is also installed between the aluminum ash slag silo's discharge port and the crusher's inlet. A quantitative feeder is also installed between the aluminum ash silo's discharge port and the slag-aluminum catalytic separation mechanism's inlet.

[0012] Preferably, the system also includes an ingot casting device. The inlet of the ingot casting device is connected to the molten aluminum outlet of the aluminum melting furnace via an aluminum molten material conveying mechanism. A palletizing robot is also installed at the discharge end of the ingot casting device.

[0013] Preferably, the slag-aluminum catalytic separation mechanism includes a separator and a catalyst stirring tank. The outlet of the catalyst stirring tank is connected to the inlet of the separator via a catalyst feeding pipe and a catalyst feeding pump. The inlet of the separator is also connected to the outlet of the aluminum ash silo via a seventh conveying mechanism. The outlet of the separator is connected to the inlet of the second screening mechanism via an eighth conveying mechanism. Preferably, a screw feeder is also provided between the separator and the seventh conveying mechanism.

[0014] Preferably, the slag-aluminum catalytic separation mechanism includes multiple catalyst stirring tanks, each of which is connected to the inlet of the separator via an independent catalyst feeding pipe and catalyst feeding pump.

[0015] Preferably, the second screening mechanism is a high-frequency vibrating screen. The screen aperture of the second screening mechanism is 1.5-5mm.

[0016] Preferably, a high-frequency screen feeding device is also provided between the second screening mechanism and the eighth conveying mechanism. The discharge port of the high-frequency screen feeding device is connected to the inlet of the second screening mechanism through a high-frequency screen feeding pipe and a high-frequency screen feeding pump.

[0017] Preferably, the reaction mechanism includes an enhanced reaction stirring tank, an oxidation stirring tank, and a carbon dioxide regulating tank arranged in series. An ozone adding device is provided on the oxidation stirring tank. A carbon dioxide adding device is provided on the carbon dioxide regulating tank. Preferably, the reaction mechanism includes multiple enhanced reaction stirring tanks, which are connected in series.

[0018] Preferably, the enhanced reaction stirring tank is also provided with a circulating feed port and a circulating discharge port. The circulating discharge port of the enhanced reaction stirring tank is connected to the circulating discharge port of the enhanced reaction stirring tank through an enhanced reaction circulating pump mechanism.

[0019] Preferably, the oxidation mixing tank is also provided with a circulating feed port and a circulating discharge port, and the circulating discharge port of the oxidation mixing tank is connected to the circulating discharge port of the oxidation mixing tank through an oxidation mixing circulating pump mechanism.

[0020] Preferably, the carbon dioxide regulating tank is also provided with a circulating feed inlet and a circulating discharge outlet. The circulating discharge outlet of the carbon dioxide regulating tank is connected to the circulating discharge outlet of the carbon dioxide regulating tank through a carbon dioxide regulating circulating pump mechanism.

[0021] Preferably, the flocculation and settling mechanism includes a settling tank and a flocculant mixing tank. The inlet of the settling tank is connected to the inlet of the carbon dioxide regulating tank via a ninth conveying mechanism. The outlet of the settling tank is connected to the inlet of the filtration and drying mechanism via a tenth conveying mechanism. The outlet of the flocculant mixing tank is connected to the inlet of the settling tank via a flocculant feeding pipe and a flocculant feeding pump. Preferably, a settling feeding pump is also provided on the ninth conveying mechanism.

[0022] Preferably, the flocculation and settling mechanism includes multiple flocculant mixing tanks, each of which is connected to the inlet of the settling tank via an independent flocculant feeding pipe and a flocculant feeding pump.

[0023] Preferably, the system also includes an inert gas protection unit, which comprises an air compressor, an air storage tank, and an inert gas preparation device connected in series. The exhaust port of the inert gas preparation device is independently connected to the air inlet of the separator, the air inlet of the second screening mechanism, the air inlet of the high-frequency screen feeding device, the air inlet of the enhanced reaction stirring tank, the air inlet of the oxidation stirring tank, the air inlet of the carbon dioxide regulating tank, and the air inlet of the settling tank via gas transmission pipelines.

[0024] Preferably, the system also includes an ammonia recovery unit, the inlet of which is independently connected to the exhaust port of the separator, the exhaust port of the second screening mechanism, the exhaust port of the high-frequency screen feeding device, the exhaust port of the enhanced reaction stirring tank, the exhaust port of the oxidation stirring tank, the exhaust port of the carbon dioxide regulating tank, and the exhaust port of the settling tank through a gas delivery pipe cover.

[0025] Preferably, the filtration and drying mechanism includes a belt filter, a dryer, a bucket elevator, and a storage silo connected in series. The inlet of the belt filter is connected to a clean water pump via an inlet pipe, and the outlet of the belt filter is connected to a concentrated brine tank via a drain pipe. Preferably, a circulating water tank is also provided on one side of the concentrated brine tank, and the concentrated brine tank and the circulating water tank are connected by a filter membrane. The circulating water tank is independently connected to the inlet of the belt filter, the inlet of the flocculant mixing tank, the inlet of the second screening mechanism, and the inlet of the catalyst mixing tank via a circulating water pump and multiple circulating water pipes.

[0026] Preferably, the system also includes a wet belt dust collector. The air inlet of the wet belt dust collector is connected to the discharge end of the dryer and the discharge end of the storage silo through multiple suction pipes and multiple suction hoods, respectively. The exhaust port of the wet belt dust collector is connected to the chimney through an exhaust pipe.

[0027] In this invention, the method for treating aluminum ash slag using an aluminum ash slag treatment system is specifically as follows:

[0028] 1) In the resource recycling unit, aluminum ash slag is crushed and ground sequentially by a crusher and a ball mill, and then screened by a first screening mechanism to obtain coarse aluminum ash slag and fine aluminum ash slag.

[0029] 2) The coarse aluminum ash slag is transported to an aluminum melting furnace for heating and melting into a molten liquid. After removing the slag, the molten liquid is sent to an ingot casting device for cooling and ingot casting to obtain aluminum ingots. At the same time, the collected slag can be returned to the aluminum ash slag from step 1).

[0030] 3) Under an inert atmosphere, the fine aluminum ash is conveyed to the slag-aluminum catalytic separation unit, where a fluorine-fixing agent and a catalyst are added and mixed to obtain a mixture. This mixture is then conveyed to a second screening unit for screening to obtain a coarse mixture and a fine mixture. The coarse mixture is also sent to an aluminum melting furnace for melting; the fine mixture undergoes further processing.

[0031] 4) Under the protection of an inert atmosphere, the fine mixture is transported to the reaction unit for enhanced mixing, oxidation and sulfur fixation reaction. After the reaction is completed, sulfur-fixed material is obtained.

[0032] 5) Under inert atmosphere protection, the sulfur-fixing material is transported to the flocculation and sedimentation unit, where flocculant and water are added and mixed for sedimentation treatment to obtain sediment residue and sedimentation liquid. The sediment residue is transported to the filtration and drying unit for filtration and drying treatment and then used as concrete raw material, while the sedimentation liquid undergoes further treatment.

[0033] 6) The settled liquid is transported to a concentrated brine tank for concentration and / or membrane filtration. Membrane filtration produces concentrated brine and purified water. The pH of the concentrated liquid and / or concentrated brine is adjusted to induce aluminum precipitation. After precipitation, the solution is filtered, and the filter residue is dried to obtain aluminum hydroxide powder. The filtrate is further concentrated to obtain a refining agent raw material. The obtained purified water (including condensate from both concentration stages) is pumped to each water-using unit for internal processing.

[0034] 7) Collect the waste gas (containing ammonia) generated in steps 3), 4), and 5) to the ammonia recovery unit for recycling (e.g., by rinsing to obtain ammonia water; the deammoniation waste gas is mainly protective gas that can be recycled).

[0035] In this invention, steps 3), 4), and 5) are all performed under an atmosphere protected by an inert gas. The denitrification gas is one of nitrogen, helium, neon, and argon, preferably nitrogen.

[0036] In this invention, the aluminum slag is one or more of aluminum slag I, aluminum slag II, and aluminum slag III. Preferably, it is a mixed aluminum slag obtained by mixing aluminum slag I, aluminum slag II, and aluminum slag III in a mass ratio of 1-3:1-2:1.5-3, more preferably a mixed aluminum slag obtained by mixing in a ratio of 1.6-2:1.1-1.5:2-2.5. Wherein, aluminum slag I comprises: Al content 39%-42%, Ca content 2%-3.5%, Mg content 0%-1.2%, F content 1%-3%, Cl content 10%-12%, S content 0.5%-0.8%, and N content 1%-5%.

[0037] Aluminum ash slag II comprises: Al content 20%–32%, Ca content 2.5%–4.5%, Mg content 2.2%–4%, F content 1.5%–2%, Cl content 6%–9%, ​​S content 0.2%–0.5%, and N content 2%–4%.

[0038] Aluminum ash slag III comprises: Al content 40%–48%, Ca content 0%–1%, Mg content 1.8%–3.8%, F content 2%–3%, Cl content 1%–5%, S content 0.4%–0.5%, and N content 3%–4%.

[0039] In this invention, the coarse aluminum ash slag in step 1) has a particle size of 1.8-5 mm, preferably 2-4 mm, and more preferably 2.5-3.5 mm. The fine aluminum ash slag has a particle size of 0.5-1.9 mm, preferably 1-1.7 mm, and more preferably 1.2-1.5 mm.

[0040] In this invention, the particle size of the coarse mixture in step 3) is 1.5-5 mm, preferably 2-4.5 mm, and more preferably 2.5-4 mm. The particle size of the fine mixture is 0.5-2 mm, preferably 0.8-1.8 mm, and more preferably 1-1.5 mm.

[0041] In this invention, the fluoride-fixing agent in step 3) is calcium acetate and / or calcium magnesium acetate. Preferably, it is a mixture of calcium acetate and calcium magnesium acetate, with a mixing mass ratio of 1:1.5-5, more preferably 1:2-3.

[0042] In this invention, the catalyst in step 3) is a mixture of polymethyl acrylate and calcium oxide. Preferably, the mass ratio of polymethyl acrylate to calcium oxide is 1:3.5-8, more preferably 1:4-5.5.

[0043] In this invention, the amount of fluorine-fixing agent added is 2-8% of the mass of fine alumina ash, preferably 3-5%, for example, one of 3%, 3.2%, 3.4%, 3.6%, 3.8%, 4%, 4.5%, and 5%. The amount of catalyst added is 3-10% of the mass of fine alumina ash, preferably 4-8%, for example, one of 3%, 3.5%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, and 8%.

[0044] In this invention, the oxidation treatment in step 4) involves introducing an oxidizing gas into the fine mixture to carry out an oxidation reaction. The oxidizing gas is oxygen or ozone.

[0045] In this invention, the sulfur fixation reaction in step 4) specifically involves introducing carbon dioxide into the oxidized fine mixture. The amount of carbon dioxide introduced is 10-30 mg / L. 3 / h, preferably 15-25m 3 / h. The reaction time is 30-120 min, preferably 40-100 min.

[0046] In this invention, the flocculant in step 5) is nonionic polyacrylamide. The mixing mass ratio of the sulfur-fixing material, flocculant, and water is 50-58:5-9:40-50, preferably 52-56:6-8:42-48. The sedimentation time is 30-120 min, preferably 40-100 min.

[0047] In this invention, the concentration factor of the sediment in step 6) is 2-7 times, preferably 2.5-5 times. Adjusting the pH of the concentrate specifically involves adjusting the pH of the concentrate and / or concentrated brine to 7-8.5, preferably 7.5-8.2. The concentration factor of the filtrate is 2-6 times, preferably 3-5 times.

[0048] In this invention, most of the metallic aluminum in the aluminum ash slag is first recovered in the aluminum ash slag pretreatment unit by mechanical dry separation. The specific process is as follows: Aluminum ash slag is loaded into the aluminum ash slag silo and fed into a vibrating feeder through a chute under the silo's outlet. A vibration anti-blocking device at the silo's outlet prevents the ash slag from clogging the outlet. The vibrating feeder then feeds the ash slag through a chute into a crusher (e.g., a jaw crusher) for crushing to 5-10mm. The crushed ash slag is then transported by a belt conveyor to a ball mill (e.g., a double-chamber ball mill) for grinding to 1-3mm. The ground ash slag is then fed into a vibrating screen for screening. The material on the screen is transported by a belt conveyor to a manual trolley, which then transports it to the aluminum melting furnace. The material undersize from the vibrating screen is conveyed by a bucket elevator to a rotary screen for tumbling. The material on the rotary screen is then conveyed by a belt conveyor to a manual trolley, which then transports it to the aluminum melting furnace. The material undersize from the rotary screen enters a screw conveyor via a screen bucket and is then transported to the aluminum ash silo by a bucket elevator. The aluminum melting furnace melts large aluminum-containing materials into aluminum. The resulting molten aluminum is conveyed to the ingot casting unit to produce aluminum ingots. Finally, a stacking robot transports the aluminum ingots to a transfer area for later use. Simultaneously, collected dust is sent to a dry belt dust collector and an aluminum melting dust removal device via dust extraction pipes and various dust collection hoods for dust removal. The dust-free flue gas is then discharged through a chimney. In essence, through mechanical and physical processes such as crushing, ball milling, and screening, metallic aluminum is initially separated from impurities (equivalent to stripping and enriching metallic aluminum from the slag phase). Then, through smelting, impurities mixed in with the metallic aluminum are removed (the slag also contains aluminum, so it is mixed and recycled with other aluminum ash for the aforementioned treatment), ultimately yielding high-quality metallic aluminum ingots.

[0049] In this invention, the fine aluminum slag in the aluminum ash silo contains a significant amount of impurities and aluminum, with some aluminum existing in the form of stable compounds. The fine aluminum slag is then transported to a slag-aluminum catalytic separation unit where a specific fluorine-fixing agent and catalyst are added. This fixes the fluorine in the fine aluminum slag while simultaneously promoting the agglomeration of aluminum-containing powder. Specifically, under the combined action of the fluorine-fixing agent and catalyst, some of the aluminum-containing powder in the fine aluminum slag agglomerates into large particles (high aluminum content). These particles are then separated by a second screening mechanism (high-frequency vibrating screen), and the large particles are returned to the aluminum melting furnace for high-temperature smelting, further achieving the separation and recovery of metallic aluminum from impurities.

[0050] In this invention, the fluorine-fixing agent is calcium acetate and / or calcium magnesium acetate, preferably a mixture of calcium acetate and calcium magnesium acetate, with a mixing mass ratio of 1:1.5-5 (preferably 1:2-3). The catalyst is a mixture of polymethyl acrylate and calcium oxide, with a mixing mass ratio of 1:3.5-8 (preferably 1:4-5). During the reaction, the catalyst promotes the reaction and also promotes the solidification of aluminum-containing powder. Excessive or insufficient mixing ratio of polymethyl acrylate and calcium oxide will reduce the catalytic effect. The fluorine-fixing agent is added in the same way as the catalyst, i.e., two catalyst stirring tanks are provided in the slag-aluminum catalytic separation mechanism, one for adding the catalyst and the other for adding the fluorine-fixing agent.

[0051] In this invention, since aluminum ash slag also contains a certain amount of sulfur, the undersize material from the second screening mechanism is transported to the reaction mechanism and subjected to one or more enhanced reactions under the protection of inert gas. Then, an oxidizing gas (such as ozone) is introduced and stirred to oxidize the sulfur. Finally, carbon dioxide is introduced and stirring is continued to achieve sulfur fixation. That is, by introducing carbon dioxide into the material, an acidic environment is created, and under the high-intensity oxidation of ozone, the sulfides in the material form calcium sulfate stabilizers in the acidic environment to achieve sulfur fixation.

[0052] In this invention, the sulfur-fixing material after the sulfur-fixing reaction is transported to a flocculation and sedimentation mechanism, where a flocculant (e.g., nonionic polyacrylamide) and water are added in a certain proportion for mixing and sedimentation. This process coagulates the microparticles generated after the sulfur-fixing reaction, as well as those generated in the preceding steps, thereby promoting the settling of the coagulated material and the clarification of the liquid. After introducing carbon dioxide and adding water, an acidic environment is created, causing most of the aluminum-containing substances to dissolve. The aluminum-free materials form precipitates under the action of the flocculant, facilitating their removal. Finally, the sulfur-fixed sedimentation material is filtered, yielding filter residue (the filter residue has a complex composition, containing carbonates and a small amount of sulfates; fixed fluorine also enters the filter residue, which can be used as a concrete raw material to produce low-strength concrete, realizing the resource utilization of the filter residue) and filtrate. The filter residue is dried to obtain concrete raw material. The filtrate is concentrated or membrane filtered to obtain a concentrated salt solution and clear water (including evaporated condensate). The clear water can be recycled. While crystallizing the concentrated salt solution, pH adjustment further dissolves metallic impurities other than aluminum, precipitating aluminum hydroxide and increasing its purity. After crystallization and precipitation, a second filtration is performed to obtain wet aluminum hydroxide powder and a second filtrate. The wet aluminum hydroxide powder is then dried to obtain aluminum hydroxide powder. Simultaneously, the second filtrate is further evaporated and concentrated to obtain the refining agent raw material. The refining agent raw material is a powdered or granular flux composed of various inorganic salts (i.e., the filtrate is concentrated to obtain various inorganic salts). Its purpose is to remove hydrogen and floating oxide inclusions from the molten aluminum during aluminum refining.

[0053] In this invention, the processing of the resource recycling unit is as follows: fine aluminum ash slag in the aluminum ash silo falls into the quantitative feeder through a chute. The quantitative feeder sends a set amount of fine aluminum ash slag to the screw feeder, which then sends the fine aluminum ash slag to the slag-aluminum separator. A catalyst is added to the slag-aluminum separator, and separation is carried out under an inert gas atmosphere. After processing, the material enters the second screening mechanism after passing through a high-frequency screen feeding device. The high-frequency screen feeding device has a stirring function and stirs the material under an inert gas atmosphere. The second screening mechanism screens the material under an inert gas atmosphere. The material on the screen enters the manual trolley through a chute, and the manual trolley then transports the material to the aluminum melting furnace for aluminum smelting. The material undersized by the second screening mechanism is sequentially fed into multiple (e.g., two) enhanced reaction mixing tanks via chutes. Under an inert gas atmosphere, it undergoes a circulating stirring reaction. Then, it enters an oxidation mixing tank, where ozone is introduced under an inert gas atmosphere for a circulating oxidation reaction. Next, it enters a carbon dioxide regulating tank, where carbon dioxide is introduced under an inert gas atmosphere for a circulating sulfur fixation reaction. Finally, it is pumped into a settling tank via a feed pump. Flocculant is then added to the settling tank via a flocculant mixing tank and a screw pump (flocculator feed pump). Settling occurs in the settling tank under an inert gas atmosphere. The material after settling is then pumped into a belt filter for pressure filtration, yielding filtrate and filter residue. The filter residue is chuted into a dryer for drying. The dried residue is then transported by a bucket elevator to a storage silo. The residue in the storage silo is further processed by a dry powder packaging and transportation device to become concrete raw material. The discharge port of the storage silo is also equipped with a vibration anti-blocking device to prevent material from blocking the outlet. The dust collection hoods installed on the dryer and storage silo collect the dust-laden flue gas to the wet bag filter for dust removal before it is discharged from the chimney.

[0054] Furthermore, the filtrate produced by the belt filter reaches the concentrated brine pool. Part of the filtrate passes through the filter membrane and enters the circulating water pool. Then, it is pumped through various water pipes to devices such as the flocculant mixing tank, belt filter, catalyst mixing tank, and high-frequency screen. The remaining filtrate in the concentrated brine pool is pumped to the external brine treatment system (i.e., for concentration and aluminum precipitation treatment to recover aluminum hydroxide powder and refining agent raw materials).

[0055] In this invention, the air compressor in the inert gas protection unit processes the air and then it enters the gas storage tank. Inert gas is then produced by the inert gas preparation device and sent to the slag-aluminum separator, the high-frequency screen feeding device, the enhanced reaction stirring tank, the oxidation stirring tank, the carbon dioxide regulating tank, the settling tank, and other devices through several gas pipes.

[0056] In this invention, ammonia gas is generated in devices such as the separator, high-frequency screen feeding device, enhanced reaction stirring tank, oxidation stirring tank, carbon dioxide regulating tank, and settling tank. Therefore, the ammonia gas is collected through several ammonia gas hoods and pipes and then sent to an ammonia recovery system for ammonia recovery. Specifically, a protective gas (such as nitrogen) is introduced during these processes to create a protective atmosphere, while the generated ammonia gas is carried out and sent to a specialized scrubbing device for scrubbing, absorption, and separation to obtain ammonia water, thereby achieving the resource recovery of harmful waste gas. Furthermore, the protective gas after ammonia removal can be recycled.

[0057] In this invention, the aluminum ash slag is a mixed aluminum ash slag composed of various aluminum ash slags with significantly different components. In existing primary aluminum production processes, due to different ore sources, the final aluminum ash slag has significantly different component contents. Some aluminum ash slags have high chlorine content (e.g., ore from coastal factories or mining areas), while others have high calcium or magnesium content. Due to the fluctuations in the content of recoverable elements in the aluminum ash slag, targeted considerations are necessary for their full resource recovery. Therefore, it is impossible to use the same processing technology to suit multiple aluminum ash slags with different component contents. Establishing a separate resource recovery production line for each type of aluminum ash slag would involve excessive investment costs and difficulties in full resource recovery, lacking economic efficiency and failing to meet the needs of economically minded enterprises. This invention utilizes a mixture of three special components of aluminum ash slag and has developed a comprehensive resource recovery process for this mixed aluminum ash slag. On one hand, it achieves the goal of recycling multiple types of aluminum ash slag using the same resource recovery process; on the other hand, the different components of the aluminum ash slag complement each other, promoting and improving the quality of resource-recovered products at each stage, thus achieving truly efficient comprehensive resource recovery of aluminum ash slag. All aluminum ash slag is resource-recovered: aluminum flakes are recycled; ammonia water is sold as a product; high-alumina materials are sold to alumina manufacturers, floor tile factories, or water purification agent factories; high-salt water is used as a raw material for refining agents, also for product sales; and concrete is used as a raw material in concrete preparation.

[0058] In this invention, each conveying mechanism (from the first to the tenth conveying mechanism) is independently one or more of the following: belt conveyor, chute, pipe chute, bucket elevator, transport vehicle, etc. A reasonable selection can be made according to actual working conditions, as long as the purpose of conveying the corresponding materials can be met.

[0059] In this invention, the height of the aluminum ash silo is 1-60m, preferably 2-40m, and more preferably 3-30m.

[0060] Compared with the prior art, the present invention has the following beneficial technical effects:

[0061] 1. The aluminum ash slag treatment system of the present invention combines a dry pretreatment unit with a wet resource recovery unit, which improves the recovery effect and efficiency of aluminum resources in aluminum ash slag while greatly reducing or even avoiding the discharge of secondary pollutants, thus realizing the efficient and green recycling of aluminum ash slag.

[0062] 2: The aluminum ash slag treatment system of the present invention realizes the resource recovery of multiple elements in aluminum ash slag through the coordinated treatment of each unit, and the various products obtained are of good quality, high strength, and high economic benefits. It also has the advantages of simple structure, easy operation, environmental friendliness and low operating cost. Attached Figure Description

[0063] Figure 1 This is a simplified structural diagram of the system described in this invention.

[0064] Figure 2 This is a schematic diagram of the overall structure of the aluminum ash slag pretreatment unit of the present invention.

[0065] Figure 3 This is a simplified structural diagram of the resource recycling unit of the present invention.

[0066] Figure 4 This is a schematic diagram of the overall structure of the resource recycling unit of the present invention.

[0067] Figure reference numerals: 1: Aluminum ash silo; 2: Crusher; 3: Ball mill; 4: First screening mechanism; 401: Vibrating screen; 402: Rotary drum screen; 5: Aluminum melting furnace; 6: Aluminum ash silo; 7: Slag-aluminum catalytic separation mechanism; 701: Separator; 702: Catalyst stirring tank; 703: Catalyst feeding pipe; 704: Catalyst feeding pump; 705: Screw feeder; 8: Second screening mechanism; 801: High-frequency screen feeding device; 802: High-frequency screen feeding pipe; 8 03: High-frequency screen feeding pump; 9: Reaction mechanism; 901: Enhanced reaction stirring tank; 902: Oxidation stirring tank; 903: Carbon dioxide regulating tank; 904: Ozone addition device; 905: Carbon dioxide addition device; 906: Enhanced reaction circulation pump mechanism; 907: Oxidation stirring circulation pump mechanism; 908: Carbon dioxide regulating circulation pump mechanism; 10: Flocculation and sedimentation mechanism; 1001: Sedimentation tank; 1002: Flocculant stirring tank; 1003: Flocculation and sedimentation mechanism; 1004: Flocculant feed pipe; 1005: Settling feed pump; 11: Filtration and drying mechanism; 1101: Belt filter; 1102: Dryer; 1103: Bucket elevator; 1104: Storage silo; 1105: Clean water pump; 1106: Concentrated brine tank; 1107: Circulating water tank; 1108: Filter membrane; 1109: Circulating water pump; 12: Dry belt dust collector; 13: Aluminum melting dust removal device; 14: Ingot casting device; 15: Palletizing robot; 16: Air compressor; 17: Air storage tank; 18: Inert gas preparation device; 19: Ammonia recovery unit; 20: Wet belt dust collector; Y1: First conveying mechanism; Y2: Second conveying mechanism; Y3: Third conveying mechanism; Y4: Fourth conveying mechanism; Y5: Fifth conveying mechanism; Y6: Sixth conveying mechanism; Y7: Seventh conveying mechanism; Y8: Eighth conveying mechanism; Y9: Ninth conveying mechanism; Y10: Tenth conveying mechanism. Detailed Implementation

[0068] The technical solution of the present invention will be illustrated below with examples. The scope of protection sought by the present invention includes, but is not limited to, the following embodiments.

[0069] An aluminum ash slag treatment system includes an aluminum ash slag pretreatment unit and a resource recovery unit. The aluminum ash slag pretreatment unit includes an aluminum ash slag silo 1, a crusher 2, a ball mill 3, a first screening mechanism 4, and an aluminum melting furnace 5, arranged in series. The resource recovery unit includes an aluminum ash silo 6, a slag-aluminum catalytic separation mechanism 7, a second screening mechanism 8, a reaction mechanism 9, a flocculation and sedimentation mechanism 10, and a filtration and drying mechanism 11, arranged in series. The oversize outlet of the first screening mechanism 4 is connected to the inlet of the aluminum melting furnace 5 via a first conveying mechanism Y1, and the undersize outlet of the first screening mechanism 4 is connected to the inlet of the aluminum ash silo 6 via a second conveying mechanism Y2. The oversize outlet of the second screening mechanism 8 is connected to the inlet of the aluminum melting furnace 5 via a third conveying mechanism Y3, and the undersize outlet of the second screening mechanism 8 is connected to the inlet of the reaction mechanism 9 via a fourth conveying mechanism Y4.

[0070] Preferably, the first screening mechanism 4 includes a vibrating screen 401 and a drum screen 402 connected in series. The oversize discharge port of the vibrating screen 401 is connected to the inlet of the aluminum melting furnace 5 through a first conveying mechanism Y1, and the undersize discharge port of the vibrating screen 401 is connected to the inlet of the drum screen 402 through a fifth conveying mechanism Y5. The oversize discharge port of the drum screen 402 is connected to the inlet of the aluminum melting furnace 5 through a sixth conveying mechanism Y6, and the undersize discharge port of the drum screen 402 is connected to the inlet of the aluminum ash silo 6 through a second conveying mechanism Y2.

[0071] Preferably, the screen aperture of the vibrating screen 401 is 5-10 mm. The screen aperture of the drum screen 402 is 1-3 mm.

[0072] Preferably, the aluminum ash slag pretreatment unit further includes a dry belt dust collector 12 and an aluminum melting dust removal device 13. The air inlet of the dry belt dust collector 12 is independently connected to the feed and / or discharge ends of the aluminum ash slag silo 1, the crusher 2, the ball mill 3, the vibrating screen 401, the drum screen 402, and the aluminum ash silo 6 via multiple suction pipes and multiple suction hoods. The air inlet of the aluminum melting dust removal device 13 is connected to the exhaust port of the aluminum melting furnace 5 via suction pipes and suction hoods. The exhaust ports of both the dry belt dust collector 12 and the aluminum melting dust removal device 13 are connected to a chimney via exhaust pipes.

[0073] Preferably, both the aluminum ash slag silo 1 and the aluminum ash silo 6 are equipped with vibration anti-clogging devices at their discharge ports. A vibrating feeder is also installed between the discharge port of the aluminum ash slag silo 1 and the feed port of the crusher 2. A quantitative feeder is also installed between the discharge port of the aluminum ash silo 6 and the feed port of the slag-aluminum catalytic separation mechanism 7.

[0074] Preferably, the system also includes an ingot casting device 14. The inlet of the ingot casting device 14 is connected to the molten aluminum outlet of the aluminum melting furnace 5 via an aluminum molten material conveying mechanism. A palletizing robot 15 is also provided at the discharge end of the ingot casting device 14.

[0075] Preferably, the slag-aluminum catalytic separation mechanism 7 includes a separator 701 and a catalyst stirring tank 702. The outlet of the catalyst stirring tank 702 is connected to the inlet of the separator 701 via a catalyst feeding pipe 703 and a catalyst feeding pump 704. The inlet of the separator 701 is also connected to the outlet of the aluminum ash silo 6 via a seventh conveying mechanism Y7. The outlet of the separator 701 is connected to the inlet of the second screening mechanism 8 via an eighth conveying mechanism Y8. Preferably, a screw feeder 705 is also provided between the separator 701 and the seventh conveying mechanism Y7.

[0076] Preferably, the slag-aluminum catalytic separation mechanism 7 includes multiple catalyst stirring tanks 702, each of which is connected to the feed inlet of the separator 701 via an independent catalyst feeding pipe 703 and a catalyst feeding pump 704.

[0077] Preferably, the second screening mechanism 8 is a high-frequency vibrating screen. The screen aperture of the second screening mechanism 8 is 1.5-5mm.

[0078] Preferably, a high-frequency screen feeding device 801 is also provided between the second screening mechanism 8 and the eighth conveying mechanism Y8. The discharge port of the high-frequency screen feeding device 801 is connected to the inlet of the second screening mechanism 8 through a high-frequency screen feeding pipe 802 and a high-frequency screen feeding pump 803.

[0079] Preferably, the reaction mechanism 9 includes a reinforced reaction stirring tank 901, an oxidation stirring tank 902, and a carbon dioxide regulating tank 903 arranged in series. An ozone adding device 904 is provided on the oxidation stirring tank 902. A carbon dioxide adding device 905 is provided on the carbon dioxide regulating tank 903. Preferably, the reaction mechanism 9 includes a plurality of reinforced reaction stirring tanks 901, which are connected in series.

[0080] Preferably, the enhanced reaction stirring tank 901 is also provided with a circulating feed port and a circulating discharge port. The circulating discharge port of the enhanced reaction stirring tank 901 is connected to the circulating discharge port of the enhanced reaction stirring tank 901 through the enhanced reaction circulating pump mechanism 906.

[0081] Preferably, the oxidation stirring tank 902 is also provided with a circulating feed port and a circulating discharge port. The circulating discharge port of the oxidation stirring tank 902 is connected to the circulating discharge port of the oxidation stirring tank 902 through the oxidation stirring circulating pump mechanism 907.

[0082] Preferably, the carbon dioxide regulating tank 903 is also provided with a circulating feed port and a circulating discharge port. The circulating discharge port of the carbon dioxide regulating tank 903 is connected to the circulating discharge port of the carbon dioxide regulating tank 903 through a carbon dioxide regulating circulating pump mechanism 908.

[0083] Preferably, the flocculation and sedimentation mechanism 10 includes a sedimentation tank 1001 and a flocculant mixing tank 1002. The inlet of the sedimentation tank 1001 is connected to the inlet of the carbon dioxide regulating tank 903 via a ninth conveying mechanism Y9. The outlet of the sedimentation tank 1001 is connected to the inlet of the filtration and drying mechanism 11 via a tenth conveying mechanism Y10. The outlet of the flocculant mixing tank 1002 is connected to the inlet of the sedimentation tank 1001 via a flocculant feeding pipe 1003 and a flocculant feeding pump 1004. Preferably, a sedimentation feeding pump 1005 is also provided on the ninth conveying mechanism Y9.

[0084] Preferably, the flocculation and sedimentation mechanism 10 includes a plurality of flocculant mixing tanks 1002, each of which is connected to the inlet of the sedimentation tank 1001 through an independent flocculant feeding pipe 1003 and a flocculant feeding pump 1004.

[0085] Preferably, the system also includes an inert gas protection unit, which comprises an air compressor 16, an air storage tank 17, and an inert gas preparation device 18 connected in series. The exhaust port of the inert gas preparation device 18 is independently connected to the air inlet of the separator 701, the air inlet of the second screening mechanism 8, the air inlet of the high-frequency screen feeding device 801, the air inlet of the enhanced reaction stirring tank 901, the air inlet of the oxidation stirring tank 902, the air inlet of the carbon dioxide regulating tank 903, and the air inlet of the settling tank 1001 via air supply pipes.

[0086] Preferably, the system also includes an ammonia recovery unit 19, the air inlet of which is independently connected to the exhaust port of the separator 701, the exhaust port of the second screening mechanism 8, the exhaust port of the high-frequency screen feeding device 801, the exhaust port of the enhanced reaction stirring tank 901, the exhaust port of the oxidation stirring tank 902, the exhaust port of the carbon dioxide regulating tank 903, and the exhaust port of the settling tank 1001 through an air supply pipe cover.

[0087] Preferably, the filtration and drying mechanism 11 includes a belt filter 1101, a dryer 1102, a bucket elevator 1103, and a storage silo 1104 connected in series. The inlet of the belt filter 1101 is connected to a clean water pump 1105 via an inlet pipe, and the outlet of the belt filter 1101 is connected to a concentrated brine tank 1106 via a drain pipe. Preferably, a circulating water tank 1107 is also provided on one side of the concentrated brine tank 1106, and the concentrated brine tank 1106 and the circulating water tank 1107 are connected by a filter membrane 1108. The circulating water tank 1107 is independently connected to the inlet of the belt filter 1101, the inlet of the flocculant mixing tank 1002, the inlet of the second screening mechanism 8, and the inlet of the catalyst mixing tank 702 via a circulating water pump 1109 and multiple circulating water pipes.

[0088] Preferably, the system also includes a wet belt dust collector 20. The air inlet of the wet belt dust collector 20 is connected to the discharge end of the dryer 1102 and the discharge end of the storage silo 1104 through multiple suction pipes and multiple suction hoods, respectively. The exhaust port of the wet belt dust collector 20 is connected to the chimney through an exhaust pipe.

[0089] Example 1

[0090] like Figure 1-4 As shown, an aluminum ash slag treatment system includes an aluminum ash slag pretreatment unit and a resource recovery unit. The aluminum ash slag pretreatment unit includes an aluminum ash slag silo 1, a crusher 2, a ball mill 3, a first screening mechanism 4, and an aluminum melting furnace 5, arranged in series. The resource recovery unit includes an aluminum ash silo 6, a slag-aluminum catalytic separation mechanism 7, a second screening mechanism 8, a reaction mechanism 9, a flocculation and sedimentation mechanism 10, and a filtration and drying mechanism 11, arranged in series. The oversize outlet of the first screening mechanism 4 is connected to the inlet of the aluminum melting furnace 5 via a first conveying mechanism Y1, and the undersize outlet of the first screening mechanism 4 is connected to the inlet of the aluminum ash silo 6 via a second conveying mechanism Y2. The oversize outlet of the second screening mechanism 8 is connected to the inlet of the aluminum melting furnace 5 via a third conveying mechanism Y3, and the undersize outlet of the second screening mechanism 8 is connected to the inlet of the reaction mechanism 9 via a fourth conveying mechanism Y4.

[0091] Example 2

[0092] The embodiment 1 is repeated, except that the first screening mechanism 4 includes a vibrating screen 401 and a drum screen 402 connected in series. The oversize discharge port of the vibrating screen 401 is connected to the feed port of the aluminum melting furnace 5 through a first conveying mechanism Y1, and the undersize discharge port of the vibrating screen 401 is connected to the feed port of the drum screen 402 through a fifth conveying mechanism Y5. The oversize discharge port of the drum screen 402 is connected to the feed port of the aluminum melting furnace 5 through a sixth conveying mechanism Y6, and the undersize discharge port of the drum screen 402 is connected to the feed port of the aluminum ash silo 6 through a second conveying mechanism Y2.

[0093] Example 3

[0094] Example 2 is repeated, except that the screen aperture of the vibrating screen 401 is 8 mm, and the screen aperture of the drum screen 402 is 3 mm.

[0095] Example 4

[0096] Example 2 is repeated, except that the screen aperture of the vibrating screen 401 is 5 mm, and the screen aperture of the drum screen 402 is 2.5 mm.

[0097] Example 5

[0098] The embodiment 4 is repeated, except that the aluminum ash slag pretreatment unit further includes a dry belt dust collector 12 and an aluminum melting dust removal device 13. The air inlet of the dry belt dust collector 12 is independently connected to the feed and discharge ends of the aluminum ash slag silo 1, the crusher 2, the ball mill 3, the vibrating screen 401, the drum screen 402, and the aluminum ash silo 6 via multiple suction pipes and multiple suction hoods. The air inlet of the aluminum melting dust removal device 13 is connected to the exhaust port of the aluminum melting furnace 5 via suction pipes and suction hoods. The exhaust ports of both the dry belt dust collector 12 and the aluminum melting dust removal device 13 are connected to the chimney via exhaust pipes.

[0099] Example 6

[0100] Example 5 is repeated, except that vibration anti-clogging devices are installed at the discharge ports of both aluminum ash slag silo 1 and aluminum ash silo 6. A vibrating feeder is also installed between the discharge port of aluminum ash slag silo 1 and the feed port of crusher 2. A quantitative feeder is also installed between the discharge port of aluminum ash silo 6 and the feed port of slag-aluminum catalytic separation mechanism 7.

[0101] Example 7

[0102] The system repeats Example 6, except that it also includes an ingot casting device 14. The inlet of the ingot casting device 14 is connected to the molten aluminum outlet of the aluminum melting furnace 5 via an aluminum molten material conveying mechanism. A palletizing robot 15 is also provided at the discharge end of the ingot casting device 14.

[0103] Example 8

[0104] The embodiment 7 is repeated, except that the slag-aluminum catalytic separation mechanism 7 includes a separator 701 and a catalyst stirring tank 702. The outlet of the catalyst stirring tank 702 is connected to the inlet of the separator 701 via a catalyst feeding pipe 703 and a catalyst feeding pump 704. The inlet of the separator 701 is also connected to the outlet of the aluminum ash silo 6 via a seventh conveying mechanism Y7. The outlet of the separator 701 is connected to the inlet of the second screening mechanism 8 via an eighth conveying mechanism Y8. A screw feeder 705 is also provided between the separator 701 and the seventh conveying mechanism Y7.

[0105] Example 9

[0106] Repeat Example 8, except that the slag-aluminum catalytic separation mechanism 7 includes multiple catalyst stirring tanks 702, each of which is connected to the feed inlet of the separator 701 through an independent catalyst feeding pipe 703 and catalyst feeding pump 704.

[0107] Example 10

[0108] Example 9 is repeated, except that the second screening mechanism 8 is a high-frequency vibrating screen. The screen aperture of the second screening mechanism 8 is 4.5 mm.

[0109] Example 11

[0110] Example 9 is repeated, except that the second screening mechanism 8 is a high-frequency vibrating screen. The screen aperture of the second screening mechanism 8 is 4 mm.

[0111] Example 12

[0112] Example 11 is repeated, except that a high-frequency screen feeding device 801 is also provided between the second screening mechanism 8 and the eighth conveying mechanism Y8. The discharge port of the high-frequency screen feeding device 801 is connected to the inlet of the second screening mechanism 8 through the high-frequency screen feeding pipe 802 and the high-frequency screen feeding pump 803.

[0113] Example 13

[0114] The process is repeated in Example 12, except that the reaction mechanism 9 includes a strengthened reaction stirring tank 901, an oxidation stirring tank 902, and a carbon dioxide regulating tank 903 arranged in series. An ozone adding device 904 is provided on the oxidation stirring tank 902. A carbon dioxide adding device 905 is provided on the carbon dioxide regulating tank 903.

[0115] Example 14

[0116] Example 13 is repeated, except that the reaction mechanism 9 includes two enhanced reaction stirring tanks 901, which are connected in series.

[0117] Example 15

[0118] Example 14 is repeated, except that the enhanced reaction stirring tank 901 is also provided with a circulating feed port and a circulating discharge port. The circulating discharge port of the enhanced reaction stirring tank 901 is connected to the circulating discharge port of the enhanced reaction stirring tank 901 through the enhanced reaction circulating pump mechanism 906.

[0119] Example 16

[0120] Example 15 is repeated, except that the oxidation stirring tank 902 is also provided with a circulating feed port and a circulating discharge port. The circulating discharge port of the oxidation stirring tank 902 is connected to the circulating discharge port of the oxidation stirring tank 902 through the oxidation stirring circulating pump mechanism 907.

[0121] Example 17

[0122] The embodiment 16 is repeated, except that the carbon dioxide regulating tank 903 is also provided with a circulating feed port and a circulating discharge port. The circulating discharge port of the carbon dioxide regulating tank 903 is connected to the circulating discharge port of the carbon dioxide regulating tank 903 through the carbon dioxide regulating circulating pump mechanism 908.

[0123] Example 18

[0124] The embodiment 17 is repeated, except that the flocculation and settling mechanism 10 includes a settling tank 1001 and a flocculant mixing tank 1002. The inlet of the settling tank 1001 is connected to the inlet of the carbon dioxide regulating tank 903 via a ninth conveying mechanism Y9. The outlet of the settling tank 1001 is connected to the inlet of the filtration and drying mechanism 11 via a tenth conveying mechanism Y10. The outlet of the flocculant mixing tank 1002 is connected to the inlet of the settling tank 1001 via a flocculant feeding pipe 1003 and a flocculant feeding pump 1004. A settling feeding pump 1005 is also provided on the ninth conveying mechanism Y9.

[0125] Example 19

[0126] Repeat Example 18, except that the flocculation and sedimentation mechanism 10 includes multiple flocculant mixing tanks 1002, each of which is connected to the inlet of the sedimentation tank 1001 through an independent flocculant feeding pipe 1003 and a flocculant feeding pump 1004.

[0127] Example 20

[0128] The system repeats Example 19, except that it also includes an inert gas protection unit, which comprises an air compressor 16, an air storage tank 17, and an inert gas preparation device 18 connected in series. The exhaust port of the inert gas preparation device 18 is independently connected to the air inlet of the separator 701, the air inlet of the second screening mechanism 8, the air inlet of the high-frequency screen feeding device 801, the air inlet of the enhanced reaction stirring tank 901, the air inlet of the oxidation stirring tank 902, the air inlet of the carbon dioxide regulating tank 903, and the air inlet of the settling tank 1001 via gas transmission pipes.

[0129] Example 21

[0130] Repeat Example 20, except that the system also includes an ammonia recovery unit 19. The air inlet of the ammonia recovery unit 19 is independently connected to the exhaust port of the separator 701, the exhaust port of the second screening mechanism 8, the exhaust port of the high-frequency screen feeding device 801, the exhaust port of the enhanced reaction stirring tank 901, the exhaust port of the oxidation stirring tank 902, the exhaust port of the carbon dioxide regulating tank 903, and the exhaust port of the settling tank 1001 through an air supply pipe cover.

[0131] Example 22

[0132] The embodiment 21 is repeated, except that the filtration and drying mechanism 11 includes a belt filter 1101, a dryer 1102, a bucket elevator 1103, and a storage silo 1104 connected in series. The inlet of the belt filter 1101 is connected to a clean water pump 1105 through an inlet pipe, and the outlet of the belt filter 1101 is connected to a concentrated brine tank 1106 through a drain pipe.

[0133] Example 23

[0134] Example 22 is repeated, except that a circulating water tank 1107 is also provided on one side of the concentrated brine tank 1106, and the concentrated brine tank 1106 and the circulating water tank 1107 are connected by a filter membrane 1108. The circulating water tank 1107 is independently connected to the inlet of the belt filter 1101, the inlet of the flocculant mixing tank 1002, the inlet of the second screening mechanism 8, and the inlet of the catalyst mixing tank 702 through a circulating water pump 1109 and multiple circulating water pipes.

[0135] Example 24

[0136] Repeat embodiment 23, except that the system also includes a wet belt dust collector 20. The air inlet of the wet belt dust collector 20 is connected to the discharge end of the dryer 1102 and the discharge end of the storage silo 1104 through multiple suction pipes and multiple suction hoods, respectively. The exhaust port of the wet belt dust collector 20 is connected to the chimney through an exhaust pipe.

[0137] Application Example 1

[0138] The aluminum ash slag is treated using the system described in Example 24. The specific process is as follows:

[0139] The aluminum ash slag is a mixed aluminum ash slag composed of aluminum ash slag I, aluminum ash slag II, and aluminum ash slag III mixed in a mass ratio of 1.8:1.3:2.4. The chemical composition of aluminum ash slag I is as follows: Al content 39%–42%, Si content 2%–5%, Fe content 1%–2%, Ca content 2%–3.5%, Mg content 0%–1.2%, F content 1%–3%, Na content 2%–7%, Cl content 10%–12%, S content 0.5%–0.8%, K content 0.2%–0.4%, and N content 1%–5%.

[0140] The chemical composition of aluminum ash slag II is as follows: Al content 20%–32%, Si content 1%–4%, Fe content 1%–1.5%, Ca content 2.5%–4.5%, Mg content 2.2%–4%, F content 1.5%–2%, Na content 3%–5%, Cl content 6%–9%, ​​S content 0.2%–0.5%, K content 0.3%–0.45%, and N content 2%–4%.

[0141] The chemical composition of aluminum ash slag III is as follows: Al content 40%–48%, Si content 3%–4%, Fe content 0.5%–1.8%, Ca content 0%–1%, Mg content 1.8%–3.8%, F content 2%–3%, Na content 4%–6%, Cl content 1%–5%, S content 0.4%–0.5%, K content 0.1%–0.2%, and N content 3%–4%.

[0142] 1) In the resource recycling unit, aluminum ash slag is crushed and ground sequentially by crusher 2 and ball mill 3, and then screened by first screening mechanism 4 to obtain coarse aluminum ash slag and fine aluminum ash slag.

[0143] 2) The coarse aluminum ash slag is transported to the aluminum melting furnace 5 and heated to melt into a liquid. After removing the slag, the liquid is sent to the ingot casting device 14 for cooling and ingot casting to obtain aluminum ingots. At the same time, the collected slag can be returned to the aluminum ash slag from step 1).

[0144] 3) Under nitrogen atmosphere protection, fine aluminum ash is conveyed to the slag-aluminum catalytic separation unit 7, and a fluorine-fixing agent and catalyst are added to the fine aluminum ash for mixing to obtain a mixture. The mixture is then conveyed to the second screening unit 8 for screening to obtain a coarse mixture and a fine mixture. The coarse mixture is also sent to the aluminum melting furnace 5 for melting; the fine mixture undergoes further processing.

[0145] 4) Under nitrogen atmosphere protection, the fine mixture is transported to the reaction unit 9 for enhanced mixing, oxidation and sulfur fixation reaction. After the reaction is completed, sulfur-fixed material is obtained.

[0146] 5) Under nitrogen atmosphere protection, the sulfur-fixing material is transported to the flocculation and sedimentation unit 10, where flocculant and water are added and mixed for sedimentation treatment to obtain sediment residue and sedimentation liquid. The sediment residue is transported to the filtration and drying unit 11 for filtration and drying treatment and then used as concrete raw material, while the sedimentation liquid undergoes further treatment.

[0147] 6) The sediment is transported to the concentrated brine tank 1106 for membrane filtration. The solution passes through membrane 110 to produce concentrated brine and purified water. The pH of the concentrated brine is adjusted to induce aluminum precipitation. After precipitation, the solution is filtered, and the filter residue is dried to obtain aluminum hydroxide powder. The filtrate is further concentrated to obtain a refining agent raw material. The obtained purified water is pumped to each water-using unit via circulating water pump 1109 for internal digestion.

[0148] 7) Collect the ammonia-containing waste gas generated in steps 3), 4), and 5) to the ammonia recovery unit 19 for recycling (obtain ammonia water through rinsing; the ammonia-removed waste gas is mainly ammonia and can be recycled).

[0149] In step 1), the particle size of coarse aluminum ash is 2-5 mm; the particle size of fine aluminum ash is 1-1.6 mm.

[0150] In step 3), the coarse mixture has a particle size of 1.6-5 mm; the fine mixture has a particle size of 1-1.5 mm. The fluorine-fixing agent is calcium acetate; the catalyst is a mixture of polymethyl acrylate and calcium oxide, with a mass ratio of polymethyl acrylate to calcium oxide of 1:4.5; the amount of fluorine-fixing agent added is 4% of the mass of the fine alumina ash; the amount of catalyst added is 7.5% of the mass of the fine alumina ash.

[0151] In step 4), the oxidation treatment involves introducing ozone into the fine mixture to carry out an oxidation reaction; in step 4), the amount of carbon dioxide introduced is 20m³. 3 / h; reaction time is 80min.

[0152] In step 5), the flocculant is nonionic polyacrylamide; the mixing mass ratio of sulfur-fixing material, flocculant, and water is 52:7:45; and the sedimentation time is 70 min.

[0153] In step 6), the concentration factor of the concentrated brine is 5 times; the pH of the concentrate is adjusted to 7-8.5; and the concentration factor of the filtrate is 4 times.

[0154] Example 1 was applied multiple times, and various parameters were adjusted without changing the system structure and processing flow to further verify the feasibility of the system. The specific parameter comparison is shown in the table below:

[0155]

[0156]

[0157]

[0158] In the table above: I represents aluminum ash slag I, II represents aluminum ash slag II, and III represents aluminum ash slag III; the mixture in the solidifying agent composition indicates the mass ratio of calcium acetate to calcium magnesium acetate; the mixture in the catalyst indicates the mass ratio of polymethyl acrylate to calcium oxide. - indicates none.

Claims

1. An aluminum ash slag treatment system, characterized in that: The system includes an aluminum ash slag pretreatment unit and a resource recovery unit; the aluminum ash slag pretreatment unit includes an aluminum ash slag bin (1), a crusher (2), a ball mill (3), a first screening mechanism (4), and an aluminum melting furnace (5) arranged in series; the resource recovery unit includes an aluminum ash bin (6), a slag-aluminum catalytic separation mechanism (7), a second screening mechanism (8), a reaction mechanism (9), a flocculation and sedimentation mechanism (10), and a filtration and drying mechanism (11) arranged in series; wherein, the oversize outlet of the first screening mechanism (4) is connected to the inlet of the aluminum melting furnace (5) through a first conveying mechanism (Y1), and the undersize outlet of the first screening mechanism (4) is connected to the inlet of the aluminum ash bin (6) through a second conveying mechanism (Y2); the oversize outlet of the second screening mechanism (8) is connected to the inlet of the aluminum melting furnace (5) through a first conveying mechanism (Y1). The third conveying mechanism (Y3) is connected to the feed inlet of the aluminum melting furnace (5), and the under-screen discharge port of the second screening mechanism (8) is connected to the feed inlet of the reaction mechanism (9) through the fourth conveying mechanism (Y4). Under the protection of nitrogen atmosphere, the fine aluminum ash is conveyed to the slag-aluminum catalytic separation mechanism (7), and a fluorine-fixing agent and a catalyst are added to the fine aluminum ash for mixing to obtain a mixture. The mixture is then conveyed to the second screening mechanism (8) for screening to obtain a coarse mixture and a fine mixture. Under the protection of nitrogen atmosphere, the fine mixture is conveyed to the reaction mechanism (9) for enhanced mixing, oxidation, and sulfur fixation reaction. After the reaction is completed, sulfur-fixed material is obtained. The fluorine-fixing agent is calcium acetate and / or calcium magnesium acetate. The catalyst is a mixture of polymethyl acrylate and calcium oxide.

2. The system according to claim 1, characterized in that: The first screening mechanism (4) includes a vibrating screen (401) and a drum screen (402) connected in series. The discharge port of the vibrating screen (401) is connected to the feed port of the aluminum melting furnace (5) through the first conveying mechanism (Y1), and the discharge port of the under-screen of the vibrating screen (401) is connected to the feed port of the drum screen (402) through the fifth conveying mechanism (Y5). The discharge port of the drum screen (402) is connected to the feed port of the aluminum melting furnace (5) through the sixth conveying mechanism (Y6), and the discharge port of the under-screen of the drum screen (402) is connected to the feed port of the aluminum ash silo (6) through the second conveying mechanism (Y2).

3. The system according to claim 2, characterized in that: The screen aperture of the vibrating screen (401) is 5-10 mm; the screen aperture of the drum screen (402) is 1-3 mm.

4. The system according to claim 2, characterized in that: The aluminum ash slag pretreatment unit also includes a dry belt dust collector (12) and an aluminum melting dust removal device (13); the air inlet of the dry belt dust collector (12) is connected to the feed end and / or discharge end of the aluminum ash slag silo (1), the feed end and / or discharge end of the crusher (2), the feed end and / or discharge end of the ball mill (3), the feed end and / or discharge end of the vibrating screen (401), the feed end and / or discharge end of the drum screen (402), and the feed end and / or discharge end of the aluminum ash silo (6) through multiple suction pipes and multiple suction hoods respectively; the air inlet of the aluminum melting dust removal device (13) is connected to the exhaust port of the aluminum melting furnace (5) through suction pipes and suction hoods; the exhaust ports of the dry belt dust collector (12) and the aluminum melting dust removal device (13) are both connected to the chimney through exhaust pipes.

5. The system according to claim 1, characterized in that: Vibration anti-clogging devices are installed at the discharge ports of both the aluminum ash slag silo (1) and the aluminum ash silo (6); a vibrating feeder is also installed between the discharge port of the aluminum ash slag silo (1) and the feed port of the crusher (2); a quantitative feeder is also installed between the discharge port of the aluminum ash silo (6) and the feed port of the slag-aluminum catalytic separation mechanism (7); and / or The system also includes an ingot casting device (14); the inlet of the ingot casting device (14) is connected to the molten outlet of the aluminum melting furnace (5) through an aluminum molten conveying mechanism; and a palletizing robot (15) is also installed at the discharge end of the ingot casting device (14).

6. The system according to any one of claims 1-5, characterized in that: The slag-aluminum catalytic separation mechanism (7) includes a separator (701) and a catalyst stirring tank (702); the outlet of the catalyst stirring tank (702) is connected to the inlet of the separator (701) through a catalyst feeding pipe (703) and a catalyst feeding pump (704); the inlet of the separator (701) is also connected to the outlet of the aluminum ash silo (6) through a seventh conveying mechanism (Y7); the outlet of the separator (701) is connected to the inlet of the second screening mechanism (8) through an eighth conveying mechanism (Y8).

7. The system according to claim 6, characterized in that: A screw feeder (705) is also provided between the separator (701) and the seventh conveying mechanism (Y7).

8. The system according to claim 6, characterized in that: The slag-aluminum catalytic separation mechanism (7) includes multiple catalyst stirring tanks (702), each of which is connected to the feed inlet of the separator (701) through an independent catalyst feeding pipe (703) and catalyst feeding pump (704).

9. The system according to claim 6, characterized in that: The second screening mechanism (8) is a high-frequency vibrating screen; the screen aperture of the second screening mechanism (8) is 1.5-5mm.

10. The system according to claim 9, characterized in that: A high-frequency screen feeding device (801) is also provided between the second screening mechanism (8) and the eighth conveying mechanism (Y8); the outlet of the high-frequency screen feeding device (801) is connected to the inlet of the second screening mechanism (8) through the high-frequency screen feeding pipe (802) and the high-frequency screen feeding pump (803).

11. The system according to claim 6, characterized in that: The reaction mechanism (9) includes an enhanced reaction stirring tank (901), an oxidation stirring tank (902), and a carbon dioxide regulating tank (903) arranged in series; an ozone adding device (904) is provided on the oxidation stirring tank (902); and a carbon dioxide adding device (905) is provided on the carbon dioxide regulating tank (903).

12. The system according to claim 11, characterized in that: The reaction mechanism (9) includes multiple enhanced reaction stirring tanks (901), which are connected in series.

13. The system according to claim 11, characterized in that: The enhanced reaction stirring tank (901) is also provided with a circulating feed port and a circulating discharge port. The circulating discharge port of the enhanced reaction stirring tank (901) is connected to the circulating discharge port of the enhanced reaction stirring tank (901) through an enhanced reaction circulating pump mechanism (906); and / or The oxidation stirring tank (902) is also provided with a circulating feed inlet and a circulating discharge outlet. The circulating discharge outlet of the oxidation stirring tank (902) is connected to the circulating discharge outlet of the oxidation stirring tank (902) through an oxidation stirring circulating pump mechanism (907); and / or The carbon dioxide regulating tank (903) is also provided with a circulating feed port and a circulating discharge port. The circulating discharge port of the carbon dioxide regulating tank (903) is connected to the circulating discharge port of the carbon dioxide regulating tank (903) through the carbon dioxide regulating circulating pump mechanism (908).

14. The system according to claim 13, characterized in that: The flocculation and settling mechanism (10) includes a settling tank (1001) and a flocculant mixing tank (1002); the inlet of the settling tank (1001) is connected to the inlet of the carbon dioxide regulating tank (903) through the ninth conveying mechanism (Y9); the outlet of the settling tank (1001) is connected to the inlet of the filtration and drying mechanism (11) through the tenth conveying mechanism (Y10); the outlet of the flocculant mixing tank (1002) is connected to the inlet of the settling tank (1001) through the flocculant feeding pipe (1003) and the flocculant feeding pump (1004).

15. The system according to claim 14, characterized in that: A settling feed pump (1005) is also installed on the ninth material conveying mechanism (Y9).

16. The system according to claim 15, characterized in that: The flocculation and settling mechanism (10) includes multiple flocculant mixing tanks (1002), each of which is connected to the inlet of the settling tank (1001) through an independent flocculant feeding pipe (1003) and a flocculant feeding pump (1004).

17. The system according to claim 16, characterized in that: The system also includes an inert gas protection unit, which includes an air compressor (16), an air storage tank (17), and an inert gas preparation device (18) connected in series. The exhaust port of the inert gas preparation device (18) is independently connected to the air inlet of the separator (701), the air inlet of the second screening mechanism (8), the air inlet of the high frequency screen feeding device (801), the air inlet of the enhanced reaction stirring tank (901), the air inlet of the oxidation stirring tank (902), the air inlet of the carbon dioxide regulating tank (903), and the air inlet of the settling tank (1001) through the gas transmission pipeline.

18. The system according to claim 17, characterized in that: The system also includes an ammonia recovery unit (19), whose inlet is independently connected to the exhaust port of the separator (701), the exhaust port of the second screening mechanism (8), the exhaust port of the high frequency screen feeding device (801), the exhaust port of the enhanced reaction stirring tank (901), the exhaust port of the oxidation stirring tank (902), the exhaust port of the carbon dioxide regulating tank (903), and the exhaust port of the settling tank (1001) through a gas transmission pipe cover.

19. The system according to claim 18, characterized in that: The filtration and drying mechanism (11) includes a belt filter (1101), a dryer (1102), a bucket elevator (1103), and a storage silo (1104) connected in series. The inlet of the belt filter (1101) is connected to a clean water pump (1105) through an inlet pipe, and the outlet of the belt filter (1101) is connected to a concentrated brine tank (1106) through a drain pipe.

20. The system according to claim 19, characterized in that: A circulating water tank (1107) is also provided on one side of the concentrated brine tank (1106), and the concentrated brine tank (1106) and the circulating water tank (1107) are connected by a filter membrane (1108); the circulating water tank (1107) is independently connected to the inlet of the belt filter (1101), the inlet of the flocculant mixing tank (1002), the inlet of the second screening mechanism (8), and the inlet of the catalyst mixing tank (702) through a circulating water pump (1109) and multiple circulating water pipes.

21. The system according to claim 20, characterized in that: The system also includes a wet belt dust collector (20). The air inlet of the wet belt dust collector (20) is connected to the discharge end of the dryer (1102) and the discharge end of the storage silo (1104) through multiple suction pipes and multiple suction hoods. The exhaust port of the wet belt dust collector (20) is connected to the chimney through the exhaust pipe.

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