Method for efficiently recovering lithium and aluminum metal components in aluminum electrolysis waste

Abstract

The invention relates to the field of aluminum electrolysis waste resource recovery, in particular to a method for efficiently recovering lithium and aluminum metal components in aluminum electrolysis waste. The method comprises the following steps: crushing waste, mixing with aluminum-containing waste and sulfuric acid, roasting, crushing and modifying the roasted waste, adding water, stirring, and filtering to obtain lithium-containing filtrate; after the filtrate is subjected to an impurity removal step, the lithium salt reacts with water-soluble carbonate or phosphate to generate a lithium finished product and mother liquor, and the mother liquor can be recycled; the filter residue and the silicon-containing substance are roasted to generate aluminum-containing oxide and silicon tetrafluoride gas, the aluminum oxide can be recycled, the treated gas can be converted into ammonium fluoride and silicon dioxide, the silicon dioxide can be further recycled, and the ammonium fluoride is used for preparing high-purity aluminum fluoride. According to the method, efficient recovery of metal components such as lithium and aluminum is achieved, and the utilization rate and economic benefits of resources are remarkably improved.

Description

Technical Field

[0001] The present invention relates to the field of aluminum electrolysis waste resource recovery, and in particular to a method for efficiently recovering lithium and aluminum metal components in aluminum electrolysis waste. Background Art

[0002] Aluminum is one of the most widely used metals in the world. During its production process, aluminum electrolysis technology converts aluminum oxide into aluminum metal. However, during the aluminum electrolysis process, a large amount of waste is generated, including aluminum electrolysis carbon slag, covering materials, overhaul slag, aluminum electrolyte, electrolytic cell lining materials, waste anode carbon blocks, waste cathode carbon blocks, etc. These wastes are rich in valuable metal components such as lithium and aluminum. If they are not effectively recovered, it will not only lead to waste of resources, but also cause serious pollution to the environment. Therefore, it is particularly important to develop a method that can efficiently recover valuable components in aluminum electrolysis waste.

[0003] In the prior art, the recycling methods of aluminum electrolysis waste are mainly divided into two categories: physical recycling and chemical recycling. The physical recycling method mainly separates aluminum metal from carbon materials through physical means such as crushing and screening, but this method cannot effectively separate aluminum from other metal elements, and the separation efficiency is low and the recovery rate is not high. The chemical recycling method separates aluminum from other elements through chemical reactions, such as leaching with acid or alkaline solutions, but this method has problems such as high consumption of chemical reagents, serious environmental pollution, and high cost.

[0004] At present, the recycling methods of aluminum electrolysis waste mainly include physical method, chemical method and electrochemical method. The physical method mainly separates aluminum and carbon by means of crushing, screening, magnetic separation and other means, but the recovery rate of this method is low and it is impossible to effectively separate impurities in aluminum and carbon. The chemical method usually uses strong acid or strong alkali for leaching. Although it can improve the recovery rate of aluminum, it seriously corrodes the equipment, and the waste liquid generated during the treatment process needs to be further treated, which increases the treatment cost and environmental risks. The electrochemical method requires specific electrolysis equipment and conditions, and the operation is complicated and the cost is high.

[0005] The limitations of existing technologies are mainly reflected in the following aspects: 1. Low recycling efficiency: Existing technology cannot effectively separate aluminum from other metal elements, resulting in a low recycling rate.

[0006] 2. Serious environmental pollution: The chemical reagents used in the chemical recovery method cause secondary pollution to the environment.

[0007] 3. High cost: Whether it is physical recycling or chemical recycling, the operation is complicated and the energy consumption is high, resulting in high recycling costs.

[0008] 4. High technical complexity: The existing technology requires complex equipment and process flow, which is not conducive to promotion and application. Summary of the invention

[0009] The present invention provides a method for efficiently recovering lithium and aluminum metal components in aluminum electrolysis waste. The method realizes efficient recovery and utilization of valuable components such as lithium and aluminum in the aluminum electrolysis waste by subjecting the aluminum electrolysis waste to the steps of crushing, roasting modification, water mixing and stirring reaction, filtering, impurity removal, lithium precipitation reaction, high-temperature roasting and ammoniation treatment. The method can effectively improve the recovery rate of aluminum, reduce environmental pollution, reduce recovery costs, and simplify the recovery process.

[0010] To achieve the above objectives, the present invention adopts the following technical solutions: A method for efficiently recovering lithium and aluminum metal components from aluminum electrolysis waste comprises the following steps: Step 1: crushing the aluminum electrolytic waste to be processed to obtain electrolytic waste particles; Step 2: the electrolytic waste particles in step 1 are fully mixed with aluminum-containing waste and sulfuric acid, and then roasted and modified to obtain modified electrolytic waste; Step 3: crushing the modified electrolytic waste in step 2, adding water, mixing and stirring, and filtering to obtain filter residue A and filtrate A; Step 4: The filtrate A in step 3 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 3 is repeated until the lithium ion concentration is ≥10 g / L to obtain a filtrate B and a filter residue B; Step 5: removing impurities from the filtrate B detected in step 4, removing the remaining hydrogen ions, fluoride ions, and aluminum ions in the solution, and separating and filtering to obtain filter residue C and filtrate C; Step 6: passing the filtrate C of step 5 into a water-soluble carbonate or phosphate, heating and stirring, and performing a lithium precipitation reaction; after separation and filtration, a lithium carbonate or lithium phosphate product and a lithium precipitation mother liquor are obtained; the lithium precipitation mother liquor is returned to step 5 for pH adjustment; Step 7: The filter residue obtained in step 3 and step 4 is fully mixed with the silicon-containing material and then calcined at high temperature to obtain a mixed gas containing aluminum oxide and silicon tetrafluoride; the aluminum oxide is returned to step 1 for reuse; Step 8: The mixed gas obtained in step 7 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 is used again in step 7; the ammonium fluoride solution reacts with aluminum salt to prepare high-purity aluminum fluoride.

[0011] Preferably, the aluminum electrolysis waste includes one or more of aluminum electrolysis carbon slag, covering material, overhaul slag and aluminum electrolyte.

[0012] Preferably, the aluminum-containing waste is one or more of aluminum ash, aluminum water, aluminum oxides in molten salt, limestone, coal ash, etc., aluminum scrap products, waste slag in aluminum processing, etc.

[0013] Preferably, the mass ratio of the electrolytic waste: the aluminum-containing waste: the sulfuric acid is 1:0.2-0.5:0.3-1.

[0014] More preferably, the mass ratio of the three is 1:0.2-0.4:0.4-0.6.

[0015] Preferably, the temperature range of the calcination reaction is 200-800° C., and the reaction time is 30-150 min.

[0016] More preferably, the reaction temperature range is 400-600° C., and the reaction time is 60-90 min.

[0017] Preferably, the temperature range of the mixing and stirring reaction with water is 0-80°C, and the reaction time is 30-120min.

[0018] More preferably, the reaction temperature range is 20-60° C., and the reaction time is 60-90 min.

[0019] Preferably, the impurity removal step is carried out in two stages: in the first stage, one or more of calcium oxide, calcium hydroxide and sodium carbonate are used to adjust the pH of the solution to 6-7 to remove excess aluminum ions and fluoride ions in the solution; in the second stage, one or more of calcium oxide, calcium hydroxide and sodium hydroxide are used to adjust the pH to 10 to remove calcium and magnesium, or magnesium and calcium are removed by using ion exchange resin; 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 time is 30-120 min.

[0020] Preferably, the silicon-containing substance is one or more of silicon dioxide, fly ash, bauxite, coal gangue, mullite, refractory bricks and thermal insulation bricks; the roasting temperature is 400-900°C; the mass ratio of the silicon addition to the filter residue is 1:0.3-0.8.

[0021] Further preferably, the calcination temperature is 600-800° C., and the mass ratio of the silicon addition to the filter residue is 1:0.4-0.6.

[0022] Preferably, the ammonia solution required for the amination reaction is one or more of ammonia water, ammonium bicarbonate, and ammonium chloride solution; the aluminum salt is one or more of aluminum chloride, aluminum sulfate, aluminum hydroxide, sodium aluminate, etc., and the ammonia water is a 5%-29% solution; the ammonium salt solution is a 5g / L saturated solution, and the aluminum salt solution is a 5g / L saturated solution.

[0023] The method for efficiently recovering lithium and aluminum metal components from aluminum electrolysis waste of the present invention effectively solves the problems of low recovery efficiency, serious environmental pollution and incomplete treatment in the prior art, and has the following advantages: 1. Improve recovery efficiency: The method of the present invention can achieve efficient separation of lithium, aluminum and other metal elements, and significantly improve the recovery rate of aluminum and lithium.

[0024] 2. Reduce environmental pollution: The present invention adopts an environmentally friendly recycling method, which reduces the use of chemical reagents and reduces pollution to the environment.

[0025] 3. Reduce recycling costs: Simplify the recycling process, reduce energy consumption and equipment investment, and thus effectively reduce recycling costs.

[0026] 4. Easy to operate and promote: The method of the present invention is simple to operate, easy to realize industrial production, and is conducive to wide promotion and application.

[0027] In summary, the present invention provides a method for efficiently recovering lithium and aluminum metal components in aluminum electrolysis waste, which not only solves the problems existing in the prior art, but also has significant technical advantages and application prospects. DETAILED DESCRIPTION

[0028] 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

[0029] A method for efficiently recovering lithium and aluminum metal components from aluminum electrolysis waste comprises the following steps: Step 1: crushing the aluminum electrolytic waste to be processed to obtain electrolytic waste particles; Step 2: the electrolytic waste particles in step 1 are fully mixed with aluminum-containing waste and sulfuric acid, and then roasted and modified to obtain modified electrolytic waste; Step 3: crushing the modified electrolytic waste in step 2, adding water, mixing and stirring, and filtering to obtain filter residue A and filtrate A; Step 4: The filtrate A in step 3 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 3 is repeated until the lithium ion concentration is ≥10 g / L to obtain a filtrate B and a filter residue B; Step 5: removing impurities from the filtrate B detected in step 4, removing the remaining hydrogen ions, fluoride ions, and aluminum ions in the solution, and separating and filtering to obtain filter residue C and filtrate C; Step 6: passing the filtrate C of step 5 into a water-soluble carbonate or phosphate, heating and stirring, and performing a lithium precipitation reaction; after separation and filtration, a lithium carbonate or lithium phosphate product and a lithium precipitation mother liquor are obtained; the lithium precipitation mother liquor is returned to step 5 for pH adjustment; Step 7: The filter residue obtained in step 3 and step 4 is fully mixed with the silicon-containing material and then calcined at high temperature to obtain a mixed gas containing aluminum oxide and silicon tetrafluoride; the aluminum oxide is returned to step 1 for reuse; Step 8: The mixed gas obtained in step 7 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 is used again in step 7; the ammonium fluoride solution reacts with aluminum salt to prepare high-purity aluminum fluoride.

[0030] Preferably, the aluminum electrolysis waste includes one or more of aluminum electrolysis carbon slag, covering material, overhaul slag and aluminum electrolyte.

[0031] Preferably, the aluminum-containing waste is one or more of aluminum ash, aluminum water and aluminum oxides in molten salt, limestone, coal ash, etc., aluminum scrap, and waste slag in aluminum processing. The reaction equation is: 2Na3AlF6+Al2O3+3H2SO4=3Na2SO4+4AlF3+3H2O 2LiNa2AlF6+Al2O3+3H2SO4=2Na2SO4+Li2SO4+4AlF3+3H2O Preferably, the mass ratio of the electrolytic waste: the aluminum-containing waste: the sulfuric acid is 1:0.2-0.5:0.3-1.

[0032] Preferably, the mass ratio of the electrolytic waste: the aluminum-containing waste: the sulfuric acid is 1:0.2-0.4:0.4-0.6.

[0033] Preferably, the temperature range of the calcination reaction is 200-800° C., and the reaction time is 30-150 min.

[0034] Preferably, the temperature range of the calcination reaction is 400-600° C., and the reaction time is 60-90 min.

[0035] Preferably, the temperature range of the mixing and stirring reaction with water is 0-80°C, and the reaction time is 30-120min.

[0036] Preferably, the temperature range of the mixing and stirring reaction with water is 20-60° C., and the reaction time is 60-90 min.

[0037] Preferably, the impurity removal step is carried out in two stages: in the first stage, one or more of calcium oxide, calcium hydroxide and sodium carbonate are used to adjust the pH of the solution to 6-7 to remove excess aluminum ions and fluoride ions in the solution; in the second stage, one or more of calcium oxide, calcium hydroxide and sodium hydroxide are used to adjust the pH to 10 to remove calcium and magnesium, or magnesium and calcium are removed by using ion exchange resin; 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 time is 30-120 min.

[0038] Preferably, the silicon-containing substance is one or more of silicon dioxide, fly ash, bauxite, coal gangue, mullite, refractory bricks and thermal insulation bricks; the roasting temperature is 400-900°C; the mass ratio of the silicon addition to the filter residue is 1:0.3-0.8.

[0039] Preferably, the calcination temperature is 600-800° C., and the mass ratio of the silicon addition to the filter residue is 1:0.4-0.6.

[0040] Preferably, the ammonia solution required for the amination reaction is one or more of ammonia water, ammonium bicarbonate, and ammonium chloride solution; the aluminum salt is one or more of aluminum chloride, aluminum sulfate, aluminum hydroxide, sodium aluminate, etc., and the ammonia water is a 5%-29% solution; the ammonium salt solution is a 5g / L saturated solution, and the aluminum salt solution is a 5g / L saturated solution. Example 2

[0041] The method for efficiently recovering lithium and aluminum metal components from aluminum electrolysis waste in Example 1 is used to recover aluminum electrolysis waste, and the steps are as follows: Step 1: Weigh 400 g of aluminum electrolyte waste and grind it into 80 mesh particles using a vibration mill; Step 2: mixing aluminum electrolytic waste: aluminum ash: sulfuric acid in a mass ratio of 1:0.2:0.5, and calcining at 550° C. for 90 min to obtain modified aluminum electrolytic waste; According to the test, the lithium content of aluminum electrolytic waste is 1.01%, the fluorine content is 33.02%, the aluminum oxide content in aluminum ash is 60%, and the lithium content of modified aluminum electrolytic waste after roasting is 0.68%, and the fluorine content is 22.5%; Step 3: crush the modified electrolytic waste and take 200 g, add water to leach it according to the solid-liquid ratio of 1:2, react at 60°C for 90 minutes, filter and wash with water to obtain a lithium-containing solution and water-leached residue; After testing, the lithium ion concentration in the solution was 2.9g / L, the lithium ion concentration in the water wash liquid was 0.2g / L, and the lithium ion leaching rate was 97.86%.

[0042] Step 4: re-introducing the leaching solution into the reactor and repeating step 3, after repeating for 3 times, obtaining repeated leaching solution and leaching residue; After testing, the lithium ion concentration in the solution was 10.28g / L; Step 5: Add sodium carbonate and sodium hydroxide to the leaching solution to remove impurities, and obtain a mixed solution containing only lithium and sodium ions. Then add a 150g / L sodium carbonate solution, react at 90°C for 90 minutes; filter, wash with water, and dry to obtain a lithium carbonate product.

[0043] After testing, the purity of lithium carbonate is 99.51%, meeting the national standard for battery-grade lithium carbonate.

[0044] Step 6: weigh and fully mix the filter residues from step 3 and step 4 at a filter residue: silicon dioxide mass ratio of 1:0.4, and calcine at 800°C for 90 minutes to obtain a calcined material; After testing, the fluoride ion content in the filter residue was 29.02%, and the fluoride ion content after roasting was 3.12%; the fluoride ion removal rate was 91.21%.

[0045] Step 7: The mixed flue gas obtained in step 6 is introduced into a 20% ammonia solution, and after reaction and solid-liquid separation and water washing, an ammonium fluoride solution and a silicon dioxide precipitate are obtained; the ammonium fluoride solution reacts with an aluminum chloride solution to prepare an aluminum fluoride product.

[0046] After testing, the fluoride ion concentration in the ammonium fluoride solution was 15g / L, and the purity reached 90% after silicon dioxide digestion; the fluoride ion content in aluminum fluoride was 59.26%, and the aluminum ion content was 30.43%, meeting the national standard requirements for aluminum fluoride. Example 3

[0047] The method for efficiently recovering lithium and aluminum metal components from aluminum electrolysis waste in Example 1 is used to recover aluminum electrolysis waste, and the steps are as follows: Step 1: Weigh 500 g of aluminum electrolyte waste and grind it into 80 mesh particles using a vibration mill; Step 2: mixing aluminum electrolytic waste: aluminum processing waste slag: sulfuric acid in a mass ratio of 1:0.3:0.4, and calcining at 550° C. for 90 min to obtain modified aluminum electrolytic waste; According to the test, the lithium content of aluminum electrolytic waste is 0.96%, the fluorine content is 32.58%, the aluminum processing waste slag has an alumina content of 64.2%, and the lithium content of the modified aluminum electrolytic waste after roasting is 0.62%, and the fluorine content is 23.21%; Step 3: crush the modified electrolytic waste and take 200 g, add water to leach it according to the solid-liquid ratio of 1:2, react at 60°C for 90 minutes, filter and wash with water to obtain a lithium-containing solution and water-leached residue; After testing, the lithium ion concentration in the solution was 3.1g / L, the lithium ion concentration in the water wash liquid was 0.3g / L, and the lithium ion leaching rate was 96.84%.

[0048] Step 4: re-introducing the leaching solution into the reactor and repeating step 3, after repeating 4 times, obtaining repeated leaching solution and leaching residue; After testing, the lithium ion concentration in the solution was 13.14g / L; Step 5: Add sodium carbonate and sodium hydroxide to the leachate to remove impurities and obtain a mixed solution containing only lithium and sodium ions. Add 150g / L sodium carbonate solution at a lithium:carbonate molar ratio of 2:1, react at 90°C for 90 minutes; filter, wash with water, and dry to obtain lithium carbonate product.

[0049] After testing, the purity of lithium carbonate is 99.54%, meeting the national standard for battery-grade lithium carbonate.

[0050] Step 6: weigh and fully mix the filter residues from step 3 and step 4 at a filter residue: silicon dioxide mass ratio of 1:0.5, and calcine at 800°C for 90 minutes to obtain a calcined material; After testing, the fluoride ion content in the filter residue was 28.64%, and the fluoride ion content after roasting was 2.68%; the fluoride ion removal rate was 95.49%.

[0051] Step 7: The mixed flue gas obtained in step 6 is introduced into a 25% ammonia solution, and after reaction and solid-liquid separation and water washing, an ammonium fluoride solution and a silicon dioxide precipitate are obtained; the ammonium fluoride solution reacts with the aluminum chloride solution to prepare an aluminum fluoride product.

[0052] After testing, the fluoride ion concentration in the ammonium fluoride solution was 18g / L, and the purity reached 92.4% after silica digestion; the fluoride ion content in aluminum fluoride was 60.52%, and the aluminum ion content was 30.14%, meeting the national standard requirements for aluminum fluoride. Example 4

[0053] The method for efficiently recovering lithium and aluminum metal components from aluminum electrolysis waste in Example 4 is basically the same as that in Example 2, except that: 1. The calcination temperature in step 2 was changed to 600°C and the calcination time was 60 min; According to the test, the lithium content of aluminum electrolytic waste is 0.96%, the fluorine content is 32.58%, the aluminum oxide content in aluminum ash is 60%, and the lithium content of modified aluminum electrolytic waste after roasting is 0.62%, and the fluorine content is 24.26%; 2. In step 3, the solid-liquid ratio is changed to 1:3, the reaction temperature is 60° C., the reaction time is 60 min, and the reaction is repeated 4 times to obtain a lithium solution and leached residue; After testing, the lithium ion concentration in the solution was 11.68g / L 3. Step 5: Add sodium carbonate solution according to the molar ratio of lithium to carbonate ion of 2:1.2, react at 80° C. for 90 min, filter, wash and dry to obtain the lithium carbonate product.

[0054] After testing, the purity of lithium carbonate is 99.50%, meeting the national standard for battery-grade lithium carbonate.

[0055] 4. The prepared aluminum fluoride has a fluoride ion content of 60.47% and an aluminum ion content of 29.84%, meeting the national standard requirements for aluminum fluoride. Example 5

[0056] The method for efficiently recovering lithium and aluminum metal components from aluminum electrolysis waste in Example 5 is basically the same as that in Example 3, except that: 1. In step 2, the aluminum processing waste slag is replaced with aluminum scrap; 2. In step 3, the reaction temperature was changed to 50°C and the reaction time was 90 min. The reaction was repeated 5 times. After testing, the lithium ion concentration in the solution was 12.97 g / L.

[0057] 3. Step 5: Add sodium carbonate solution according to the molar ratio of lithium to carbonate ion of 2:1.2, react at 80° C. for 90 min, filter, wash and dry to obtain the lithium carbonate product.

[0058] After testing, the purity of lithium carbonate is 99.50%, meeting the national standard for battery-grade lithium carbonate.

[0059] 4. The prepared aluminum fluoride has a fluoride ion content of 59.42% and an aluminum ion content of 29.58%, meeting the national standard requirements for aluminum fluoride. Example 6

[0060] The method for efficiently recovering lithium and aluminum metal components from aluminum electrolysis waste in Example 6 is basically the same as that in Example 2, except that: 1. Step 5: Add sodium phosphate solution at a lithium: phosphate molar ratio of 3:1.1, react at 80°C for 90 minutes, filter, wash and dry to obtain lithium phosphate product. After testing, the purity of lithium phosphate is 90.62%.

[0061] 2. The prepared aluminum fluoride has a fluoride ion content of 59.21% and an aluminum ion content of 28.87%, meeting the national standard requirements for aluminum fluoride.

[0062] 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 lithium and aluminum metal components from aluminum electrolysis waste, characterized in that: The following steps are involved: Step 1: crushing the aluminum electrolytic waste to be processed to obtain electrolytic waste particles; Step 2: the electrolytic waste particles in step 1 are fully mixed with aluminum-containing waste and sulfuric acid, and then roasted and modified to obtain modified electrolytic waste; Step 3: crushing the modified electrolytic waste in step 2, adding water, mixing and stirring, and filtering to obtain filter residue A and filtrate A; Step 4: The filtrate A in step 3 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 3 is repeated until the lithium ion concentration is ≥10 g / L to obtain a filtrate B and a filter residue B; Step 5: removing impurities from the filtrate B detected in step 4, removing the remaining hydrogen ions, fluoride ions, and aluminum ions in the solution, and separating and filtering to obtain filter residue C and filtrate C; Step 6: passing the filtrate C of step 5 into a water-soluble carbonate or phosphate, heating and stirring, and performing a lithium precipitation reaction; after separation and filtration, a lithium carbonate or lithium phosphate product and a lithium precipitation mother liquor are obtained; the lithium precipitation mother liquor is returned to step 5 for pH adjustment; Step 7: The filter residue obtained in step 3 and step 4 is fully mixed with the silicon-containing material and then calcined at high temperature to obtain a mixed gas containing aluminum oxide and silicon tetrafluoride; the aluminum oxide is returned to step 1 for reuse; Step 8: The mixed gas obtained in step 7 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 is used again in step 7; the ammonium fluoride solution reacts with aluminum salt to prepare high-purity aluminum fluoride.

2. The method for efficiently recovering lithium and aluminum metal components from aluminum electrolysis waste according to claim 1, characterized in that: The aluminum electrolysis waste in step 1 includes one or more of aluminum electrolysis carbon slag, covering material, overhaul slag and aluminum electrolyte; the aluminum-containing waste in step 2 includes one or more of aluminum ash, aluminum water and aluminum oxides in molten salt, limestone, coal ash, etc., aluminum scrap products, waste slag in aluminum processing, etc.; the mass ratio of electrolytic waste: aluminum-containing waste: sulfuric acid in step 2 is 1:0.2-0.5:0.3-1.

3. The method for efficiently recovering lithium and aluminum metal components from aluminum electrolysis waste according to claim 1, characterized in that: In the step 2, the mass ratio of electrolytic waste: aluminum-containing waste: sulfuric acid is 1:0.2-0.4:0.4-0.6, the temperature range of the roasting reaction in the step 2 is 200-800°C, and the reaction time is 30-150min.

4. The method for efficiently recovering lithium and aluminum metal components from aluminum electrolysis waste according to claim 1, characterized in that: The temperature range of the calcination reaction in step 2 is 400-600° C., and the reaction time is 60-90 min.

5. The method for efficiently recovering lithium and aluminum metal components from aluminum electrolysis waste according to claim 1, characterized in that: The temperature range of the mixing and stirring reaction with water in step 3 is 0-80° C., and the reaction time is 30-120 min.

6. The method for efficiently recovering lithium and aluminum metal components from aluminum electrolysis waste according to claim 1, characterized in that: The temperature range of the mixing and stirring reaction with water in step 3 is 20-60° C., and the reaction time is 60-90 min.

7. The method for efficiently recovering lithium and aluminum metal components from aluminum electrolysis waste according to claim 1, characterized in that: In step 5, the impurity removal step is carried out in 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 calcium oxide, calcium 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.

8. The method for efficiently recovering lithium and aluminum metal components from aluminum electrolysis waste according to claim 1, characterized in that: The water-soluble carbonate in step 6 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 time is 30-120 min.

9. The method for efficiently recovering lithium and aluminum metal components from aluminum electrolysis waste according to claim 1, characterized in that: The silicon-containing substance in step 7 is one or more of silicon dioxide, fly ash, bauxite, coal gangue, mullite, refractory bricks and thermal insulation bricks; the roasting temperature is 400-900°C; the mass ratio of the silicon addition amount to the filter residue is 1:0.3-0.

8.

10. The method for efficiently recovering lithium and aluminum metal components from aluminum electrolysis waste according to claim 1, characterized in that: The ammonia solution required for the amination reaction in step 8 is one or more of ammonia water, ammonium bicarbonate, and ammonium chloride solution; the aluminum salt is one or more of aluminum chloride, aluminum sulfate, aluminum hydroxide, sodium aluminate, etc., and the ammonia water is a 5%-29% solution; the ammonium salt solution is a 5g / L saturated solution, and the aluminum salt solution is a 5g / L saturated solution.