Method for efficiently recycling aluminum electrolysis waste

Abstract

The invention belongs to the technical field of aluminum electrolysis industrial waste treatment, and particularly relates to a method for efficiently recycling aluminum electrolysis waste. The method comprises the following steps: mixing crushed aluminum electrolysis waste with a silicon-containing substance and sulfuric acid, and then roasting and modifying; mixing and stirring the modified waste with water, and filtering to separate filter residues and filtrate; removing impurities from the filtrate to obtain purified filtrate and filter residues; reacting the purified filtrate with water-soluble carbonate or phosphate to prepare lithium carbonate or lithium phosphate; 2, the mixed gas generated in the first step is subjected to ammoniation treatment, an ammonium fluoride solution and silicon dioxide are prepared, silicon dioxide can be recycled, and the ammonium fluoride solution is used for preparing high-purity aluminum fluoride. The invention provides an efficient and environment-friendly aluminum electrolysis waste recycling method, lithium resources in the waste can be effectively recycled, fluorine in the waste can be converted into high-purity aluminum fluoride, cyclic utilization of the resources is achieved, the resource utilization rate is increased, and environmental pollution is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of aluminum electrolysis industrial waste treatment, and specifically relates to a method for efficiently recovering aluminum electrolysis waste. Background Art

[0002] Aluminum, as the third most abundant element on earth, has a wide range of applications. It is not only widely used as a structural material in the construction industry, but also widely used in the transportation field to manufacture vehicles such as automobiles and airplanes due to its lightweight characteristics. In addition, in the packaging industry, aluminum cans, foils and other products can also be seen everywhere. The production of aluminum mainly depends on the electrolysis of alumina from bauxite, but this process produces a large amount of waste, including residues from aluminum electrolytic cells, waste anode carbon blocks, etc. If these wastes are not properly handled, they will cause serious pollution to the environment. Therefore, the development of a method for efficiently recycling aluminum electrolytic waste is of great significance to economic and environmental protection.

[0003] Traditional aluminum electrolysis waste recycling technologies mainly include pyrometallurgy, hydrometallurgy and electrochemical recycling. Pyrometallurgy extracts valuable metals from waste through high-temperature smelting, but this method has high energy consumption, serious pollution, and may pose a threat to the health of operators. Hydrometallurgy uses acid and alkali solutions to dissolve valuable metals in waste, but a large amount of wastewater and waste residue will be generated during the treatment process, which pollutes the environment and requires additional steps to treat these wastewater and waste residue. Although electrochemical recovery has a high recovery efficiency, it has large equipment investment, high operating costs, and special requirements for the operating environment.

[0004] In recent years, significant research progress has been made in the field of aluminum electrolysis waste recycling. For example, biotechnology is used to treat aluminum electrolysis waste, and the valuable metals in the waste are converted into recyclable forms through the action of microorganisms. This method is relatively environmentally friendly, but its recycling efficiency and processing speed still need to be further improved. In addition, some researchers have tried to separate the valuable metals from non-metals in the waste and recycle them separately. This method is feasible in theory, but in actual operation it faces problems such as high technical difficulty and high cost.

[0005] Despite this, the current aluminum electrolytic waste recycling technology still has limitations: (1) Low recycling efficiency: The existing technology cannot achieve efficient separation of aluminum and carbon, resulting in a low recovery rate of aluminum metal, which not only affects the full utilization of resources, but also increases the processing cost. (2) Serious environmental pollution: The waste liquid and waste gas generated during the chemical and electrochemical treatment processes cause secondary pollution to the environment, which not only violates the principle of sustainable development, but also brings potential environmental risks to enterprises. (3) High cost: The physical and chemical methods have high processing costs, and the strong acids and alkalis used in the chemical method are expensive, which increases the economic burden of enterprises. (4) High equipment requirements: The electrochemical method requires specific electrolytic equipment, with high investment costs and high maintenance costs, which makes it difficult for many small and medium-sized enterprises to afford. Therefore, it is of great practical significance to study an efficient, environmentally friendly and economical aluminum electrolytic waste recycling method. Summary of the invention

[0006] The purpose of the present invention is to provide a method for efficiently recycling aluminum electrolytic waste to solve the problems of difficulty in separating aluminum and carbon, low recovery efficiency, serious environmental pollution, high cost and incomplete treatment in the prior art. The method not only improves the recovery rate of aluminum metal through innovative process flow and the use of environmentally friendly materials, but also significantly reduces pollution to the environment and reduces overall treatment costs, thereby having good economic and environmental benefits.

[0007] To achieve the above objectives, the present invention adopts the following technical solutions: A method for efficiently recycling aluminum electrolysis waste comprises the following steps: Step 1: crushing the aluminum electrolytic waste to be treated, fully mixing it with silicon-containing substances and sulfuric acid, and then roasting and modifying it to obtain modified electrolytic waste and mixed gas; Step 2: crushing the modified electrolytic waste in step 1, mixing with water, stirring and reacting, and filtering to obtain filter residue A and filtrate A; Step 3: The filtrate A in step 2 is a lithium-containing leaching solution. The lithium ion concentration in the filtrate A is detected by an instrument. If the lithium ion concentration in the filtrate A is ≤10 g / L, the filtrate is re-introduced into the reactor, and step 2 is repeated until the lithium ion concentration is ≥10 g / L to obtain a filtrate B and a filter residue B; Step 4: remove impurities from the filtrate B detected in step 3, remove the remaining fluorine, aluminum, calcium and magnesium ions in the solution, separate and filter to obtain filter residue C and filtrate C; the filter residue C is returned to step 1 for roasting; Step 5: passing the filtrate C of step 4 into a water-soluble carbonate or phosphate, heating and stirring, and performing a lithium precipitation reaction; after separation and filtration, a finished product of lithium carbonate or lithium phosphate is obtained; Step 6: The mixed gas obtained in step 1 is subjected to ammoniation treatment to obtain a mixture of ammonium fluoride solution and silicon dioxide; after solid-liquid separation and water washing, the silicon dioxide mixture is used again in step 1; the ammonium fluoride solution reacts with aluminum salt to prepare high-purity aluminum fluoride.

[0008] Preferably, the aluminum electrolysis waste includes one or more of aluminum electrolysis carbon slag, covering material, overhaul slag and aluminum electrolyte.

[0009] Preferably, the silicon-containing substance is one or more of silicon dioxide, fly ash, bauxite, coal gangue, mullite, refractory bricks and thermal insulation bricks.

[0010] Preferably, the mass ratio of the electrolytic waste, the silicon-containing substance and the sulfuric acid is 1:0.1-0.8:0.3-1.

[0011] Further preferably, the mass ratio of the three is 1:0.2-0.4:0.4-0.6.

[0012] Preferably, the calcination reaction temperature range is 200-800° C., and the reaction time is 30-150 minutes.

[0013] More preferably, the reaction temperature is in the range of 400-600° C., and the reaction time is in the range of 60-90 minutes.

[0014] Preferably, the temperature range of the mixing and stirring reaction with water is 0-80° C., and the reaction time is 30-120 minutes.

[0015] More preferably, the reaction temperature is in the range of 20-60° C., and the reaction time is in the range of 60-90 minutes.

[0016] Preferably, the impurity removal step is divided into two stages: in the first stage, one or more of calcium oxide, calcium hydroxide, and sodium carbonate are used to adjust the solution pH to 6-7 to remove excess aluminum ions and fluoride ions; in the second stage, one or more of ammonia water, potassium hydroxide, and sodium hydroxide are used to adjust the pH to 10 to remove calcium and magnesium, or magnesium and calcium are removed using ion exchange resins.

[0017] Preferably, the water-soluble carbonate is one or two of sodium carbonate, potassium carbonate and hydrates thereof, and the phosphate is one or two of potassium phosphate and sodium phosphate; the reaction temperature is 70-90° C., and the reaction time is 30-120 minutes.

[0018] Preferably, the ammonia water is 5%-10% dilute ammonia water or concentrated ammonia water; the aluminum salt is one or more of aluminum chloride, aluminum sulfate, aluminum hydroxide, sodium aluminate, etc.

[0019] The method for efficiently recycling aluminum electrolytic waste of the present invention effectively solves the problems of low recycling efficiency, serious environmental pollution and incomplete treatment in the prior art, and has the following advantages: 1. High recovery rate: Through roasting treatment, the present invention can effectively dissolve lithium and aluminum metals in waste materials and collect useful fluoride ions, thereby achieving efficient separation and recovery of lithium, aluminum and fluorine to obtain high-purity aluminum fluoride and lithium carbonate or lithium phosphate products.

[0020] 2. Environmentally friendly: The roasting treatment method adopted by the present invention reduces the use of chemical reagents and reduces pollution to the environment.

[0021] 3. Low cost: The process of the present invention is simple and easy to operate. It does not require complicated equipment and operation. It reduces the recycling cost by improving the recycling efficiency and reducing the consumption of chemical reagents.

[0022] 4. Wide applicability: The present invention is applicable to various types of aluminum electrolysis waste, including aluminum electrolysis carbon slag, covering material, overhaul slag, aluminum electrolyte, etc. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Example 1

[0024] A method for efficiently recycling aluminum electrolysis waste comprises the following steps: Step 1: crushing the aluminum electrolytic waste to be treated, fully mixing it with silicon-containing substances and sulfuric acid, and then roasting and modifying it to obtain modified electrolytic waste and mixed gas; Step 2: crushing the modified electrolytic waste in step 1, mixing with water, stirring and reacting, and filtering to obtain filter residue A and filtrate A; Step 3: The filtrate A in step 2 is a lithium-containing leaching solution. The lithium ion concentration in the filtrate A is detected by an instrument. If the lithium ion concentration in the filtrate A is ≤10 g / L, the filtrate is re-introduced into the reactor, and step 2 is repeated until the lithium ion concentration is ≥10 g / L to obtain a filtrate B and a filter residue B; Step 4: remove impurities from the filtrate B detected in step 3, remove the remaining fluorine, aluminum, calcium and magnesium ions in the solution, separate and filter to obtain filter residue C and filtrate C; the filter residue C is returned to step 1 for roasting; Step 5: passing the filtrate C of step 4 into a water-soluble carbonate or phosphate, heating and stirring, and performing a lithium precipitation reaction; after separation and filtration, a finished product of lithium carbonate or lithium phosphate is obtained; Step 6: The mixed gas obtained in step 1 is subjected to ammoniation treatment to obtain a mixture of ammonium fluoride solution and silicon dioxide; after solid-liquid separation and water washing, the silicon dioxide mixture is used again in step 1; the ammonium fluoride solution reacts with aluminum salt to prepare high-purity aluminum fluoride.

[0025] Preferably, the aluminum electrolysis waste includes one or more of aluminum electrolysis carbon slag, covering material, overhaul slag and aluminum electrolyte.

[0026] Preferably, the silicon-containing substance is one or more of silicon dioxide, fly ash, bauxite, coal gangue, mullite, refractory bricks and thermal insulation bricks.

[0027] Preferably, the mass ratio of the electrolytic waste, the silicon-containing substance and the sulfuric acid is 1:0.1-0.8:0.3-1.

[0028] Further preferably, the mass ratio of the three is 1:0.2-0.4:0.4-0.6.

[0029] Preferably, the calcination reaction temperature range is 200-800° C., and the reaction time is 30-150 minutes.

[0030] More preferably, the reaction temperature is in the range of 400-600° C., and the reaction time is in the range of 60-90 minutes.

[0031] The reaction equation is: 2LiNa2AlF6+3SiO2+6H2SO4=2Na2SO4+Li2SO4+Al2(SO4)3+3SiF4+6H2O Al2(SO4)3=Al2O3+3SO3 3S+2Al2(SO4)3=2Al2O3+9SO2 Preferably, the temperature range of the mixing and stirring reaction with water is 0-80° C., and the reaction time is 30-120 minutes.

[0032] More preferably, the reaction temperature is in the range of 20-60° C., and the reaction time is in the range of 60-90 minutes.

[0033] Preferably, the impurity removal step is divided into two stages: in the first stage, one or more of calcium oxide, calcium hydroxide, and sodium carbonate are used to adjust the solution pH to 6-7 to remove excess aluminum ions and fluoride ions; in the second stage, one or more of ammonia water, potassium hydroxide, and sodium hydroxide are used to adjust the pH to 10 to remove calcium and magnesium, or magnesium and calcium are removed using ion exchange resins.

[0034] Preferably, the water-soluble carbonate is one or two of sodium carbonate, potassium carbonate and hydrates thereof, and the phosphate is one or two of potassium phosphate and sodium phosphate; the reaction temperature is 70-90° C., and the reaction time is 30-120 minutes.

[0035] The reaction equation is: SiF4+4NH4OH=4NH4F+SiO2+2H2O 3NH4F+Al 3+ =3NH4 + +AlF3 Preferably, the ammonia water is 5%-10% dilute ammonia water or concentrated ammonia water; the aluminum salt is one or more of aluminum chloride, aluminum sulfate, aluminum hydroxide, sodium aluminate, etc.

[0036] The prepared high-purity aluminum fluoride is reused in the aluminum electrolysis process or used as a catalyst in the synthesis of organic compounds and organic fluorine compounds, and the obtained lithium carbonate or lithium phosphate products are used in the battery and semiconductor industries. Example 2

[0037] The method for efficiently recovering aluminum electrolysis waste in Example 1 is used to recover aluminum electrolysis waste, and the steps are as follows: Step 1: Weigh 500g of aluminum electrolyte and crush it into particles of about 100 mesh using a vibration mill; and fully mix the electrolyte, silicon dioxide and sulfuric acid according to the mass ratio of electrolytic waste: silicon-containing material: sulfuric acid of 1:0.4:0.6, place it at 600°C and roast it for 90 minutes to obtain a modified aluminum electrolyte and crush it; After testing, the lithium content of aluminum electrolyte was 1.01%, and the fluorine content was 32.68%; after roasting, the lithium content was 0.66%, and the fluorine content was 2.14%; the fluoride ion removal rate was 92.89%.

[0038] Step 2: Weigh 200g of modified electrolyte, add water according to the solid-liquid ratio of 1:2, stir and react at 60°C for 90min; separate the solid and liquid to obtain lithium-containing filtrate and filter residue; after testing, the lithium ion concentration in the filtrate is 3.1g / L; Step 3: The filtrate from step 2 is reintroduced into the reactor, and step 2 is repeated for 3 times to obtain a filtrate and filter residue with a higher lithium concentration; after testing, the lithium concentration after enrichment is 10.23 g / L; Step 4: Use sodium hydroxide and sodium carbonate to remove impurities from the filtrate to obtain a lithium and sodium mixed solution, which is precipitated into a mixture of aluminum hydroxide, aluminum fluoride, calcium hydroxide, etc., and returned to the first stage for roasting; Step 5: adding sodium carbonate according to the molar ratio of lithium to carbonate 2:1, reacting at 90°C for 60 minutes to obtain a lithium carbonate product; after testing, the purity of the lithium carbonate is 99.36%, which meets the national standard requirements for industrial-grade lithium carbonate; Step 6: The mixed flue gas obtained in step 1 is introduced into an ammonia solution with a concentration of 20%, and after an amination reaction, an ammonium fluoride solution and silicon dioxide are obtained after solid-liquid separation; the silicon dioxide is returned to step 1 for reuse; the ammonium fluoride solution reacts with the aluminum chloride solution, and the aluminum fluoride product is obtained after solid-liquid separation.

[0039] After testing, the fluoride ion concentration in the ammonium fluoride solution was 15g / L, and the purity reached 90% after silicon dioxide digestion; the fluorine content in the prepared aluminum fluoride was 59.46%, and the aluminum content was 30.21%, meeting the national standard requirements for aluminum fluoride. Example 3

[0040] The method for efficiently recovering aluminum electrolysis waste in Example 1 is used to recover aluminum electrolysis waste, and the steps are as follows: Step 1: Weigh 500g of aluminum electrolytic covering material, and crush it into particles of about 100 mesh using a vibration mill; and fully mix the electrolyte, silicon dioxide and sulfuric acid according to the mass ratio of electrolytic waste: silicon-containing material: sulfuric acid of 1:0.4:0.6, and place it at 600°C for 90 minutes to roast, obtain a modified aluminum covering material and crush it; After testing, the lithium content of the aluminum covering material was 0.85%, and the fluorine content was 36.27%; after roasting, the lithium content was 0.54%, and the fluorine content was 3.26%; the fluoride ion removal rate was 91.85%.

[0041] Step 2: Weigh 200g of the modified covering material, add water according to the solid-liquid ratio of 1:2, stir and react at 60°C for 90min; separate the solid and liquid to obtain a lithium-containing filtrate and a filter residue; after testing, the lithium ion concentration in the filtrate is 2.8g / L; Step 3: The filtrate from step 2 is reintroduced into the reactor, and step 2 is repeated 4 times to obtain a filtrate and filter residue with a higher lithium concentration; after testing, the lithium concentration after enrichment is 11.56 g / L; Step 4: Use sodium hydroxide and sodium carbonate to remove impurities from the filtrate to obtain a lithium and sodium mixed solution, which is precipitated into a mixture of aluminum hydroxide, aluminum fluoride, calcium hydroxide, etc., and returned to the first stage for roasting; Step 5: adding sodium carbonate according to the molar ratio of lithium to carbonate 2:1, reacting at 90°C for 60 minutes to obtain a lithium carbonate product; after testing, the purity of the lithium carbonate is 99.26%, which meets the national standard requirements for industrial-grade lithium carbonate; Step 6: The mixed flue gas obtained in step 1 is introduced into an ammonia solution with a concentration of 25%, and after an amination reaction, an ammonium fluoride solution and silicon dioxide are obtained after solid-liquid separation; the silicon dioxide is returned to step 1 for reuse; the ammonium fluoride solution reacts with the aluminum chloride solution, and the aluminum fluoride product is obtained after solid-liquid separation.

[0042] After testing, the fluoride ion concentration in the ammonium fluoride solution was 18g / L, and the purity reached 88.49% after silica digestion testing; the fluorine content in the prepared aluminum fluoride was 60.14%, and the aluminum content was 29.48%, meeting the national standard requirements for aluminum fluoride. Example 4

[0043] The method for efficiently recovering aluminum electrolysis waste in Example 1 is used to recover aluminum electrolysis waste, and the steps are as follows: Step 1: Weigh 500g of aluminum electrolysis overhaul slag and crush it into particles of about 100 mesh using a vibration mill; and fully mix the electrolyte, silicon dioxide and sulfuric acid according to the mass ratio of electrolytic waste: silicon-containing material: sulfuric acid of 1:0.4:0.6, and place it at 800℃ for 90min to roast, obtain modified aluminum overhaul slag and crush it; According to the test, the lithium content of aluminum overhaul slag is 0.55%, and the fluorine content is 20.68%; after roasting, the lithium content is 0.32%, and the fluorine content is 0.46%; the fluoride ion removal rate is 95.69%.

[0044] Step 2: Weigh 200g of modified covering material, add water according to the solid-liquid ratio of 1:2, stir and react at 60°C for 90min; separate the solid and liquid to obtain lithium-containing filtrate and filter residue; after testing, the lithium ion concentration in the filtrate is 2.1g / L; Step 3: The filtrate from step 2 is reintroduced into the reactor, and step 2 is repeated for 6 times to obtain a filtrate and filter residue with a higher lithium concentration; after testing, the lithium concentration after enrichment is 13.48 g / L; Step 4: Use sodium hydroxide and sodium carbonate to remove impurities from the filtrate to obtain a lithium and sodium mixed solution, which is precipitated into a mixture of aluminum hydroxide, aluminum fluoride, calcium hydroxide, etc., and returned to the first stage for roasting; Step 5: adding sodium carbonate according to the molar ratio of lithium to carbonate 2:1, reacting at 90°C for 60 minutes to obtain a lithium carbonate product; after testing, the purity of the lithium carbonate is 99.21%, which meets the national standard requirements for industrial-grade lithium carbonate; Step 6: The mixed flue gas obtained in step 1 is introduced into an ammonia solution with a concentration of 15%, and after an amination reaction, an ammonium fluoride solution and silicon dioxide are obtained after solid-liquid separation; the silicon dioxide is returned to step 1 for reuse; the ammonium fluoride solution reacts with the aluminum chloride solution, and the aluminum fluoride product is obtained after solid-liquid separation.

[0045] After testing, the fluoride ion concentration in the ammonium fluoride solution was 12g / L, and the purity reached 86.94% after silica digestion testing; the fluorine content in the prepared aluminum fluoride was 58.49%, and the aluminum content was 28.94%, meeting the national standard requirements for aluminum fluoride. Example 5

[0046] The method for efficiently recovering aluminum electrolysis waste in Example 5 is basically the same as that in Example 2, except that: The calcination temperature was changed to 800°C and the calcination time was 60 min; After testing, the lithium content of aluminum electrolyte was 1.01%, and the fluorine content was 33.68%; after roasting, the lithium content was 0.68%, and the fluorine content was 1.36%; the fluoride ion removal rate was 95.69%.

[0047] Sodium carbonate was added according to the molar ratio of lithium: carbonate ion of 2:1.1, and the reaction was carried out at 90°C for 60 minutes. After solid-liquid separation and water washing, a lithium carbonate product was obtained. After testing, the purity of the lithium carbonate reached 99.26%, meeting the national standard requirements for industrial-grade lithium carbonate.

[0048] Step 1: The mixed flue gas is passed into concentrated ammonia water to obtain ammonium fluoride and silicon dioxide. After testing, the fluoride ion concentration in the ammonium fluoride solution is 20.4 g / L, and the purity of silicon dioxide reaches 86.4% after digestion testing. The prepared aluminum fluoride has a fluorine content of 61.5% and an aluminum content of 27.98%, which meets the national standard requirements for aluminum fluoride. Example 6

[0049] The method for efficiently recovering aluminum electrolysis waste in Example 6 is basically the same as that in Example 3, except that: 1. The roasting temperature was changed to 700℃ and the roasting time was 90min; After testing, the lithium content of aluminum electrolyte was 0.99% and the fluorine content was 35.31%; after roasting, the lithium content was 0.60% and the fluorine content was 3.12%; the fluoride ion removal rate was 94.28%.

[0050] 2. Sodium carbonate was added according to the molar ratio of lithium to carbonate of 2:1.1, and the reaction was carried out at 90°C for 60 minutes. After solid-liquid separation and water washing, a lithium carbonate product was obtained. After testing, the purity of the lithium carbonate reached 99.36%, which met the national standard requirements for industrial-grade lithium carbonate.

[0051] 3. In step 1, the mixed flue gas is passed into concentrated ammonia water to obtain ammonium fluoride and silicon dioxide. After testing, the fluoride ion concentration in the ammonium fluoride solution is 18.5 g / L, and the purity of silicon dioxide reaches 90% after digestion testing. The fluorine content of the prepared aluminum fluoride is 61.46%, and the aluminum content is 28.21%, which meets the national standard requirements for aluminum fluoride. Example 7

[0052] The method for efficiently recovering aluminum electrolysis waste in Example 7 is basically the same as that in Example 2, except that: 1. Sodium carbonate was added according to the molar ratio of lithium to phosphate of 3:1.1, and the reaction was carried out at 80°C for 60 minutes. After solid-liquid separation and water washing, lithium phosphate product was obtained; after testing, the purity of lithium phosphate reached 90.48%.

[0053] 2. In step 1, the mixed flue gas is passed into concentrated ammonia water to obtain ammonium fluoride and silicon dioxide. After testing, the fluoride ion concentration in the ammonium fluoride solution is 18.5 g / L, and the purity of silicon dioxide reaches 90% after digestion testing. The fluorine content of the prepared aluminum fluoride is 61.46%, and the aluminum content is 28.21%, which meets the national standard requirements for aluminum fluoride.

[0054] Although the content of the present invention has been described in detail through the above preferred embodiments, it should be appreciated that the above description should not be considered as a limitation of the present invention. After reading the above content, it will be apparent to those skilled in the art that various modifications and substitutions of the present invention will occur. Therefore, the protection scope of the present invention should be limited by the appended claims.

Claims

1. A method for efficiently recovering aluminum electrolysis waste, characterized in that: The following steps are involved: Step 1: crushing the aluminum electrolytic waste to be treated, fully mixing it with silicon-containing substances and sulfuric acid, and then roasting and modifying it to obtain modified electrolytic waste and mixed gas; Step 2: crushing the modified electrolytic waste in step 1, mixing with water, stirring and reacting, and filtering to obtain filter residue A and filtrate A; Step 3: The filtrate A in step 2 is a lithium-containing leaching solution. The lithium ion concentration in the filtrate A is detected by an instrument. If the lithium ion concentration in the filtrate A is ≤10 g / L, the filtrate is re-introduced into the reactor, and step 2 is repeated until the lithium ion concentration is ≥10 g / L to obtain a filtrate B and a filter residue B; Step 4: remove impurities from the filtrate B detected in step 3, remove the remaining fluorine, aluminum, calcium and magnesium ions in the solution, separate and filter to obtain filter residue C and filtrate C; the filter residue C is returned to step 1 for roasting; Step 5: passing the filtrate C of step 4 into a water-soluble carbonate or phosphate, heating and stirring, and performing a lithium precipitation reaction; after separation and filtration, a finished product of lithium carbonate or lithium phosphate is obtained; Step 6: The mixed gas obtained in step 1 is subjected to ammoniation treatment to obtain a mixture of ammonium fluoride solution and silicon dioxide; after solid-liquid separation and water washing, the silicon dioxide mixture is used again in step 1; the ammonium fluoride solution reacts with aluminum salt to prepare high-purity aluminum fluoride.

2. The method for efficiently recovering aluminum electrolytic waste according to claim 1, characterized in that: In step 1, the aluminum electrolysis waste includes one or more of aluminum electrolysis carbon slag, covering material, overhaul slag and aluminum electrolyte, and the silicon-containing substance is one or more of silicon dioxide, fly ash, bauxite, coal gangue, mullite, refractory bricks and thermal insulation bricks. In step 1, the mass ratio of electrolytic waste: silicon-containing substance: sulfuric acid is 1:0.1-0.8:0.3-1.

3. The method for efficiently recovering aluminum electrolytic waste according to claim 1, characterized in that: In the step 1, the mass ratio of electrolytic waste: silicon-containing material: sulfuric acid is 1:0.2-0.4:0.4-0.

6.

4. The method for efficiently recovering aluminum electrolytic waste according to claim 1, characterized in that: The temperature range of the calcination reaction in step 1 is 200-800° C., and the reaction time is 30-150 min.

5. The method for efficiently recovering aluminum electrolytic waste according to claim 1, characterized in that: The temperature range of the calcination reaction in step 1 is 400-600° C., and the reaction time is 60-90 min.

6. The method for efficiently recovering aluminum electrolytic waste according to claim 1, characterized in that: The temperature range of the mixing and stirring reaction with water in step 2 is 0-80° C., and the reaction time is 30-120 min.

7. The method for efficiently recovering aluminum electrolytic waste according to claim 1, characterized in that: The temperature range of the mixing and stirring reaction with water in step 2 is 20-60° C., and the reaction time is 60-90 min.

8. The method for efficiently recovering aluminum electrolytic waste according to claim 1, characterized in that: In step 4, the impurity removal step is divided into two stages: the first stage uses one or more of calcium oxide, calcium hydroxide, and sodium carbonate to adjust the solution pH to 6-7 to remove excess aluminum ions and fluoride ions in the solution; the second stage uses one or more of ammonia water, potassium hydroxide, and sodium hydroxide to adjust the pH to 10 to remove calcium and magnesium, or uses ion exchange resin to remove magnesium and calcium.

9. The method for efficiently recovering aluminum electrolytic waste according to claim 1, characterized in that: The water-soluble carbonate in step 5 is one or two of sodium carbonate, potassium carbonate and their hydrates, and the phosphate is one or two of potassium phosphate and sodium phosphate; the reaction temperature is 70-90° C.; and the reaction time is 30-120 min.

10. The method for efficiently recovering aluminum electrolytic waste according to claim 1, characterized in that: In step 6, the ammonia water is 5%-10% dilute ammonia water or concentrated ammonia water; the aluminum salt is one or more of aluminum chloride, aluminum sulfate, aluminum hydroxide, sodium aluminate, etc.