Method for efficiently recycling aluminum electrolysis waste by using ion recombination technology

Abstract

The invention belongs to the technical field of aluminum electrolysis waste recovery treatment, and particularly relates to a method for efficiently recovering aluminum electrolysis waste through an ion recombination technology. The method comprises the following steps: crushing the aluminum electrolysis waste, mixing with the aluminum-containing waste and sulfuric acid, roasting and modifying; mixing and stirring the modified waste and water, and filtering; carrying out impurity removal and concentration on the filtrate, and adding carbonate or phosphate to initiate a lithium precipitation reaction; mixing the filter residue and the filtrate precipitate with an alkaline solution, carrying out an alkaline leaching reaction to prepare a sodium metaaluminate mixed solution, and washing the filter residue with water to obtain a sodium fluoride solution; introducing carbon dioxide into the mixed solution or adjusting the pH value to 10-12 to obtain an aluminum hydroxide precipitate and a sodium carbonate solution; the sodium fluoride solution reacts with ammonia water to prepare an ammonium fluoride solution and sodium hydroxide, ammonium fluoride is used for preparing high-purity aluminum fluoride, and the sodium hydroxide solution is recycled. According to the method, valuable elements such as aluminum, lithium and fluorine in the aluminum electrolysis waste can be efficiently recycled, cyclic utilization of resources is promoted, and environmental pollution is effectively reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of recycling and processing of aluminum electrolysis waste, and specifically relates to a method for efficiently recycling aluminum electrolysis waste by utilizing ion recombination technology. Background Art

[0002] Aluminum, as one of the most widely used metals in the world, plays an extremely important role in many fields such as construction, automobile manufacturing, aerospace, packaging and power transmission. Its excellent physical and chemical properties such as light weight, high strength and corrosion resistance are the main reasons for its wide application. With the continuous deepening of the application of aluminum materials in these fields, the market demand for aluminum has also shown a continuous growth trend. However, in the production process of aluminum, a large amount of electrolytic waste is inevitably generated. If these wastes are not properly handled and recycled, it will not only cause a waste of precious aluminum resources, but also may cause serious pollution to the environment.

[0003] In the field of traditional aluminum electrolytic waste treatment, physical and chemical treatment methods are mainly relied on. However, these traditional methods often have some common problems, such as relatively low aluminum recovery rate, high energy consumption in the treatment process, and possible environmental pollution problems in the treatment process. Summary of the invention

[0004] The purpose of the present invention is to provide a method for efficiently recovering aluminum electrolytic waste using ion recombination technology, aiming to solve the problems existing in the prior art. The present invention uses a specific ion recombination agent to effectively separate aluminum ions from other metal ions in the waste, and achieves efficient recovery of aluminum through a specific process flow, and effectively reduces energy consumption during the treatment process, while significantly reducing pollution to the environment.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions: A method for efficiently recovering aluminum electrolysis waste using ion recombination technology comprises the following steps: Step 1: crushing the aluminum electrolytic waste to be treated, fully mixing it with aluminum-containing waste and sulfuric acid, and then roasting and modifying it to obtain modified electrolytic waste; Step 2: crush the modified electrolytic waste material, mix with water, stir and react, and filter to obtain filter residue A and filtrate A; the filtrate A is filtered and concentrated after impurity removal, and a soluble carbonate or phosphate is added to carry out lithium precipitation reaction; Step 3: The filter residue A and the impurity-removing precipitate of the filtrate A obtained in step 2 are mixed with an alkaline solution to carry out an alkaline leaching reaction to obtain a mixed solution of sodium aluminate, sodium hydroxide and sodium fluoride; and the filter residue A is washed with water for multiple times to obtain a sodium fluoride solution; Step 4: introducing carbon dioxide into the mixed solution obtained in step 3 or using an acid solution to adjust the pH of the solution to 10-12 to obtain aluminum hydroxide precipitate and sodium carbonate / sodium salt solution; the sodium carbonate / sodium salt solution is returned to the system for recycling; Step 5: The sodium fluoride solution obtained in step 3 is reacted with ammonia water / ammonium salt solution using an ion recombination device to obtain an ammonium fluoride solution and a sodium hydroxide solution or a sodium salt; the ammonium fluoride solution is reacted with the aluminum hydroxide / aluminum salt prepared in step 3 to prepare high-purity aluminum fluoride, and the sodium hydroxide solution or the sodium salt is reused.

[0006] Preferably, the aluminum electrolysis waste includes one or more of aluminum electrolysis carbon slag, covering material, overhaul slag and aluminum electrolyte.

[0007] 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 products, waste slag in aluminum processing, etc.; in step 1, the mass ratio of electrolytic waste: aluminum-containing waste: sulfuric acid is 1:0.2-0.5:0.3-1.

[0008] Preferably, in step 1, the mass ratio of electrolytic waste: aluminum-containing waste: sulfuric acid is 1:0.2-0.4:0.4-0.6.

[0009] Preferably, the soluble carbonate 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. Preferably, the alkaline solution is a sodium hydroxide solution, the mass ratio of leaching residue A to sodium hydroxide is 1:0.5-1; the solid-liquid ratio is 1:3-20; and the number of water washings is 3-8 times.

[0010] Preferably, the alkaline solution is a sodium hydroxide solution, the mass ratio of leaching residue A to sodium hydroxide is 1:0.6-0.9; the solid-liquid ratio is 1:5-10; and the number of water washings is 4-6 times.

[0011] Preferably, the ion recombination device comprises a plurality of FCDI modules and a plurality of liquid storage tanks, the FCDI modules comprise a first FCDI module, a second FCDI module, a third FCDI module and a fourth FCDI module, the liquid storage tanks comprise a first liquid storage tank, a second liquid storage tank, a third liquid storage tank, a fourth liquid storage tank, a fifth liquid storage tank and a sixth liquid storage tank, the first FCDI module is provided with a first cation exchange membrane and a first anion exchange membrane, the first cation exchange membrane and the first anion exchange membrane divide the interior of the first FCDI module into a first anode chamber, a first separation chamber and a first cathode chamber, the second FCDI module is provided with a second cation exchange membrane and a second anion exchange membrane, the second cation exchange membrane and the second anion exchange membrane divide the interior of the second FCDI module into a second anode chamber, a first separation chamber and a first cathode chamber, The third FCDI module is provided with a third cation exchange membrane and a third anion exchange membrane, and the third cation exchange membrane and the third anion exchange membrane divide the interior of the third FCDI module into a third anode chamber, a third synthesis chamber and a third cathode chamber. The fourth FCDI module is provided with a fourth cation exchange membrane and a fourth anion exchange membrane, and the fourth cation exchange membrane and the fourth anion exchange membrane divide the interior of the fourth FCDI module into a fourth anode chamber, a fourth synthesis chamber and a fourth cathode chamber; the first liquid storage tank, the first anode chamber, the first cathode chamber, the third anode chamber and the fourth cathode chamber form a first circulation system via a pipeline, and the second liquid storage tank, the second anode chamber, the second cathode chamber, the fourth anode chamber and the third cathode chamber form a second circulation system via a pipeline.

[0012] Preferably, the first liquid storage tank and the second liquid storage tank respectively store activated carbon solutions, and the mass fraction of the solid phase carbon content of the activated carbon solutions ranges from 5% to 60%.

[0013] Preferably, the third liquid storage tank stores the sodium fluoride solution prepared in step 3, the mass concentration of the sodium fluoride solution is 10 g / L saturated concentration, the fourth liquid storage tank stores ammonia water / ammonium salt solution, the mass concentration of the ammonia water / ammonium salt solution is 10 g / L saturated concentration, and the ammonium salt solution is specifically one or more of ammonium carbonate, ammonium bicarbonate, ammonium sulfate, ammonium chloride, etc.; the fifth liquid storage tank and the sixth liquid storage tank are used to store the sodium salt solution and ammonium fluoride solution after ion reorganization, respectively.

[0014] Preferably, in step 5, the sodium fluoride solution obtained in step 3 is reacted with ammonia water / ammonium salt solution using an ion recombination device, comprising the following steps: S51: a sodium fluoride solution and an ammonium salt solution with a mass concentration of 10 g / L are circulated in the first separation chamber and the second separation chamber respectively; an activated carbon slurry with a mass fraction range of 10%-60% is filled in the first liquid storage device and the second liquid storage device respectively; S52: Start the device to start the first circulation system circulation. When the activated carbon slurry passes through the first anode chamber and the first cathode chamber, under the action of the electric field, the anions and cations in the soluble carbonate solution in the first separation chamber are adsorbed by the carbon slurry through the anion and cation membrane. When the carbon slurry rich in anions and cations passes through the third anode chamber and the fourth cathode chamber, under the action of the opposite electric field, the anions and cations in the carbon slurry are desorbed into the third synthesis chamber and the fourth synthesis chamber through the anion and cation membrane. The third synthesis chamber receives cations, and the fourth synthesis chamber receives anions. The reaction temperature range of this process is controlled to be 10-50°C, the circulation flow rate range in the first circulation system is 5-60mL / min, and the power supply applied voltage range is 0.2-8V; S53: After the first circulation system is completed, the second circulation system is entered. When the activated carbon slurry passes through the second anode chamber and the second cathode chamber, under the action of the electric field, the anions and cations in the lithium salt solution in the second separation chamber are adsorbed by the carbon slurry through the anion and cation membrane. When the carbon slurry rich in anions and cations passes through the fourth anode chamber and the third cathode chamber, under the action of the opposite electric field, the anions and cations in the carbon slurry are desorbed into the fourth synthesis chamber and the third synthesis chamber through the anion and cation membrane. The fourth synthesis chamber receives cations, and the third synthesis chamber receives anions. The reaction temperature range of this process is controlled to be 10-50°C, the circulation flow rate range in the second circulation system is 5-60ml / min, and the power supply voltage range is 0.2-8V; S54: After the second circulation system is completed, anions and cations combine in the third synthesis chamber to form a sodium salt solution, and anions and cations combine in the fourth synthesis chamber to form an ammonium fluoride solution.

[0015] Preferably, the molar ratio of the reaction between the ammonium fluoride solution prepared by the ion recombination device and the aluminum salt is 3:0.8-1.1.

[0016] Preferably, the molar ratio of the ammonium fluoride solution prepared by the ion recombination device to the aluminum salt is 3:0.9-1.

[0017] The method of the present invention for efficiently recovering aluminum electrolysis waste by using ion recombination technology effectively solves the problems of low recovery efficiency, serious environmental pollution and incomplete treatment in the prior art, and has the following advantages: By utilizing ion recombination technology, effective separation of aluminum or lithium from other metals is achieved, thereby improving the recovery rate of aluminum or lithium.

[0018] By precisely controlling the electrolysis conditions, ion recombination technology can produce high-purity aluminum fluoride or lithium carbonate, reducing the use of chemical reagents and lowering environmental pollution.

[0019] This technology generates less waste during the recycling process and has the advantages of easy operation, low energy consumption, and environmental friendliness. It has good economic and environmental benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of the structure of an ion recombination device according to an embodiment of the present invention.

[0021] Figure numerals: 1-first FCDI module; 2-second FCDI module; 3-third FCDI module; 4-fourth FCDI module; 11-first cation exchange membrane; 12-first anion exchange membrane; 21-second cation exchange membrane; 22-second anion exchange membrane; 31-third cation exchange membrane; 32-third anion exchange membrane; 41-fourth cation exchange membrane; 42-fourth anion exchange membrane; 5-first liquid storage tank; 6-second liquid storage tank; 7-third liquid storage tank; 8-fourth liquid storage tank; 9-fifth liquid storage tank; 10-sixth liquid storage tank.

[0022] The present invention is described in detail below with reference to the accompanying drawings and specific implementation methods. 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 recovering aluminum electrolysis waste using ion recombination technology comprises the following steps: Step 1: crushing the aluminum electrolytic waste to be treated, fully mixing it with aluminum-containing waste and sulfuric acid, and then roasting and modifying it to obtain modified electrolytic waste; Step 2: crush the modified electrolytic waste material, mix with water, stir and react, and filter to obtain filter residue A and filtrate A; the filtrate A is filtered and concentrated after impurity removal, and a soluble carbonate or phosphate is added to carry out lithium precipitation reaction; Step 3: The filter residue A and the impurity-removing precipitate of the filtrate A obtained in step 2 are mixed with an alkaline solution to carry out an alkaline leaching reaction to obtain a mixed solution of sodium aluminate, sodium hydroxide and sodium fluoride; and the filter residue A is washed with water for multiple times to obtain a sodium fluoride solution; Step 4: introducing carbon dioxide into the mixed solution obtained in step 3 or using an acid solution to adjust the pH of the solution to 10-12 to obtain aluminum hydroxide precipitate and sodium carbonate / sodium salt solution; the sodium carbonate / sodium salt solution is returned to the system for recycling; Step 5: The sodium fluoride solution obtained in step 3 is reacted with ammonia water / ammonium salt solution using an ion recombination device to obtain an ammonium fluoride solution and a sodium hydroxide solution or a sodium salt; the ammonium fluoride solution is reacted with the aluminum hydroxide / aluminum salt prepared in step 3 to prepare high-purity aluminum fluoride, and the sodium hydroxide solution or the sodium salt is reused.

[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 aluminum-containing waste is 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.; in step 1, the mass ratio of electrolytic waste: aluminum-containing waste: sulfuric acid is 1:0.2-0.5:0.3-1.

[0027] Preferably, in step 1, the mass ratio of electrolytic waste: aluminum-containing waste: sulfuric acid is 1:0.2-0.4:0.4-0.6.

[0028] Preferably, the soluble carbonate 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. Preferably, the alkaline solution is a sodium hydroxide solution, the mass ratio of leaching residue A to sodium hydroxide is 1:0.5-1; the solid-liquid ratio is 1:3-20; and the number of water washings is 3-8 times.

[0029] Preferably, the alkaline solution is a sodium hydroxide solution, the mass ratio of leaching residue A to sodium hydroxide is 1:0.6-0.9; the solid-liquid ratio is 1:5-10; and the number of water washings is 4-6 times.

[0030] Preferably, if Figure 1As shown, the ion recombination device includes a plurality of FCDI modules and a plurality of liquid storage tanks, wherein the FCDI modules include a first FCDI module 1, a second FCDI module 2, a third FCDI module 3 and a fourth FCDI module 4, wherein the liquid storage tanks include a first liquid storage tank 5, a second liquid storage tank 6, a third liquid storage tank 7, a fourth liquid storage tank 8, a fifth liquid storage tank 9 and a sixth liquid storage tank 10, wherein the first FCDI module 1 is provided with a first cation exchange membrane 11 and a first anion exchange membrane 12, wherein the first cation exchange membrane 11 and the first anion exchange membrane 12 divide the interior of the first FCDI module 1 into a first anode chamber, a first separation chamber and a first cathode chamber, wherein the second FCDI module 2 is provided with a second cation exchange membrane 21 and a second anion exchange membrane 22, wherein the second cation exchange membrane 21 and the second anion exchange membrane 22 divide the interior of the second FCDI module 2 into a second anode chamber, a second separation chamber and a second cathode chamber, wherein the third FCDI module 3 is provided with a third cation exchange membrane 31 and a third anion exchange membrane 32, wherein the third cation exchange membrane 32 and the third anion exchange membrane 31 are provided with a third anion exchange membrane 32, wherein the third cation exchange membrane 31 and the third anion exchange membrane 32 ... The membrane 31 and the third anion exchange membrane 32 divide the interior of the third FCDI module 3 into a third anode chamber, a third synthesis chamber and a third cathode chamber. The fourth FCDI module 4 is provided with a fourth cation exchange membrane 41 and a fourth anion exchange membrane 42. The fourth cation exchange membrane 41 and the fourth anion exchange membrane 42 divide the interior of the fourth FCDI module 4 into a fourth anode chamber, a fourth synthesis chamber and a fourth cathode chamber. The third liquid storage tank 7 is passed through a pipeline into the first separation chamber and then circulates into the third liquid storage tank 7; the fourth liquid storage tank 8 is passed through a pipeline into the second separation chamber and then circulates into the fourth liquid storage tank 8; the fifth liquid storage tank 9 is passed through a pipeline into the third synthesis chamber and then circulates into the fifth liquid storage tank 9; the sixth liquid storage tank 10 is passed through a pipeline into the fourth synthesis chamber and then circulates into the sixth liquid storage tank 10; the first liquid storage tank 5, the first anode chamber, the first cathode chamber, the third anode chamber and the fourth cathode chamber form a first circulation system via a pipeline, and the second liquid storage tank 6, the second anode chamber, the second cathode chamber, the fourth anode chamber and the third cathode chamber form a second circulation system via a pipeline.

[0031] Preferably, the first liquid storage tank and the second liquid storage tank respectively store activated carbon solutions, and the mass fraction of the solid phase carbon content of the activated carbon solutions ranges from 5% to 60%.

[0032] Preferably, the third liquid storage tank stores the sodium fluoride solution prepared in step 3, the mass concentration of the sodium fluoride solution is 10 g / L saturated concentration, the fourth liquid storage tank stores ammonia water / ammonium salt solution, the mass concentration of the ammonia water / ammonium salt solution is 10 g / L saturated concentration, and the ammonium salt solution is specifically one or more of ammonium carbonate, ammonium bicarbonate, ammonium sulfate, ammonium chloride, etc.; the fifth liquid storage tank and the sixth liquid storage tank are used to store the sodium salt solution and ammonium fluoride solution after ion reorganization, respectively.

[0033] Preferably, in step 5, the sodium fluoride solution obtained in step 3 is reacted with ammonia water / ammonium salt solution using an ion recombination device, comprising the following steps: S51: a sodium fluoride solution and an ammonium salt solution with a mass concentration of 10 g / L are circulated in the first separation chamber and the second separation chamber respectively; an activated carbon slurry with a mass fraction range of 10%-60% is filled in the first liquid storage device and the second liquid storage device respectively; S52: Start the device to start the first circulation system circulation. When the activated carbon slurry passes through the first anode chamber and the first cathode chamber, under the action of the electric field, the anions and cations in the soluble carbonate solution in the first separation chamber are adsorbed by the carbon slurry through the anion and cation membrane. When the carbon slurry rich in anions and cations passes through the third anode chamber and the fourth cathode chamber, under the action of the opposite electric field, the anions and cations in the carbon slurry are desorbed into the third synthesis chamber and the fourth synthesis chamber through the anion and cation membrane. The third synthesis chamber receives cations, and the fourth synthesis chamber receives anions. The reaction temperature range of this process is controlled to be 10-50°C, the circulation flow rate range in the first circulation system is 5-60mL / min, and the power supply applied voltage range is 0.2-8V; S53: After the first circulation system is completed, the second circulation system is entered. When the activated carbon slurry passes through the second anode chamber and the second cathode chamber, under the action of the electric field, the anions and cations in the lithium salt solution in the second separation chamber are adsorbed by the carbon slurry through the anion and cation membrane. When the carbon slurry rich in anions and cations passes through the fourth anode chamber and the third cathode chamber, under the action of the opposite electric field, the anions and cations in the carbon slurry are desorbed into the fourth synthesis chamber and the third synthesis chamber through the anion and cation membrane. The fourth synthesis chamber receives cations, and the third synthesis chamber receives anions. The reaction temperature range of this process is controlled to be 10-50°C, the circulation flow rate range in the second circulation system is 5-60ml / min, and the power supply voltage range is 0.2-8V; S54: After the second circulation system is completed, anions and cations combine in the third synthesis chamber to form a sodium salt solution, and anions and cations combine in the fourth synthesis chamber to form an ammonium fluoride solution.

[0034] Preferably, the molar ratio of the reaction between the ammonium fluoride solution prepared by the ion recombination device and the aluminum salt is 3:0.8-1.1.

[0035] Preferably, the molar ratio of the ammonium fluoride solution prepared by the ion recombination device to the aluminum salt is 3:0.9-1. Example 2

[0036] The method for efficiently recovering aluminum electrolysis waste using ion recombination technology in Example 1 is used to recover aluminum electrolysis waste, and the steps are as follows: Step 1: Weigh 500g of aluminum electrolyte, crush it, fully mix the electrolyte, aluminum ash and sulfuric acid according to the mass ratio of electrolytic waste: aluminum ash: sulfuric acid of 1:0.4:0.6, roast it at 600℃ for 90min, cool it down and crush it to obtain modified electrolytic waste particles; Step 2: Weigh 500g of modified electrolytic waste and add water according to the solid-liquid ratio of 1:2, place it at 60℃ and stir for 60min, after solid-liquid separation, add sodium hydroxide and sodium carbonate to the filtrate to remove impurities, filter and separate, and concentrate the filtrate to obtain a high-concentration lithium salt solution. Add sodium carbonate according to the lithium: carbonate molar ratio of 2:1 and react at 90℃ for 60min to obtain a lithium carbonate product; After testing, the purity of lithium carbonate is 99.58%, which meets the national standard requirements for battery-grade lithium carbonate; Step 3: adding sodium hydroxide solution to the filter residue obtained in step 2 at a solid-liquid ratio of 1:3 and a filter residue: sodium hydroxide mass ratio of 1:0.7 to react by stirring to obtain a mixed solution of sodium hydroxide, sodium metaaluminate and sodium fluoride; after washing with water 5 times, collecting and obtaining a sodium fluoride solution; Step 4: Add carbon dioxide to the mixed solution in step 3, adjust the solution pH to 12, separate the solid and liquid to obtain aluminum hydroxide and sodium carbonate solution; after testing, the aluminum content in aluminum hydroxide is 33.81%. The concentration of sodium carbonate is 110g / L; the sodium carbonate solution is returned to step 2 to prepare lithium carbonate.

[0037] Step 5: preparing an ammonium fluoride solution by using an ion recombination device, wherein the activated carbon mass fraction in the activated carbon slurry is 10%; placing a saturated sodium fluoride solution and an ammonium bicarbonate solution in the first and second separation chambers; the flow rate of the first and second circulation systems is 20 ml / min; and the power supply voltage is 1.5 V; After testing, the fluoride ion concentration in the ammonium fluoride solution prepared by the ion recombination device was 16g / L; Step 6: According to the fluorine: aluminum molar ratio of 3:1, use ammonium fluoride solution to react with the aluminum hydroxide slurry prepared in step 4 to obtain ammonium fluoroaluminate precipitate, and then obtain aluminum fluoride product after roasting.

[0038] After testing, the fluorine content in the prepared aluminum fluoride was 58.49% and the aluminum content was 28.76%, which met the national standard requirements for aluminum fluoride. Example 3

[0039] A method for efficiently recovering aluminum electrolysis waste using ion recombination technology in Example 1 is used to recover aluminum electrolysis waste, and the steps are as follows: Step 1: Weigh 500g of overhaul slag, crush it, and fully mix the overhaul slag, aluminum scrap and sulfuric acid according to the mass ratio of electrolytic waste: aluminum scrap: sulfuric acid of 1:0.4:0.6, roast it at 600℃ for 90min, cool it down and crush it to obtain modified electrolytic waste particles; Step 2: Weigh 500g of modified electrolytic waste and add water according to the solid-liquid ratio of 1:2, place it at 60℃ and stir for 60min, after solid-liquid separation, add calcium oxide to the filtrate to remove impurities, filter and separate, and concentrate the filtrate to obtain a high-concentration lithium salt solution. Add sodium carbonate according to the lithium: carbonate molar ratio of 2:1.1 and react at 80℃ for 60min to obtain a lithium carbonate product; After testing, the purity of lithium carbonate is 99.51%, which meets the national standard requirements for battery-grade lithium carbonate; Step 3: adding sodium hydroxide solution to the filter residue obtained in step 2 at a solid-liquid ratio of 1: 5 and a filter residue: sodium hydroxide mass ratio of 1: 0.5 to carry out stirring reaction to obtain a mixed solution of sodium hydroxide, sodium metaaluminate and sodium fluoride; after washing with water 6 times, collecting and obtaining a sodium fluoride solution; Step 4: Add carbon dioxide to the mixed solution of step 3, adjust the solution pH to 12, separate the solid and liquid to obtain aluminum hydroxide and sodium carbonate solution; after testing, the aluminum content in aluminum hydroxide is 32.78%. The concentration of sodium carbonate is 106g / L; the sodium carbonate solution is returned to step 2 to prepare lithium carbonate.

[0040] Step 5: preparing an ammonium fluoride solution by using an ion recombination device, wherein the activated carbon mass fraction in the activated carbon slurry is 20%; placing a saturated sodium fluoride solution and an ammonium bicarbonate solution in the first and second separation chambers; the flow rate of the first and second circulation systems is 30 ml / min; and the power supply voltage is 1.2 V; After testing, the fluoride ion concentration in the ammonium fluoride solution prepared by the ion recombination device was 18g / L; Step 6: According to the fluorine:aluminum molar ratio of 3.05:1, use ammonium fluoride solution to react with the aluminum hydroxide slurry prepared in step 4 to obtain ammonium fluoroaluminate precipitate, and then obtain aluminum fluoride product after roasting.

[0041] After testing, the fluorine content in the prepared aluminum fluoride was 58.69% and the aluminum content was 29.42%, which met the national standard requirements for aluminum fluoride. Example 4

[0042] The method for efficiently recovering aluminum electrolysis waste using ion recombination technology in Example 1 is used to recover aluminum electrolysis waste, and the steps are as follows: Step 1: Weigh 500g of the covering material, crush it, and fully mix the covering material, aluminum processing waste and sulfuric acid according to the mass ratio of electrolytic waste: aluminum processing waste: sulfuric acid of 1:0.2:0.4, roast it at 550°C for 60min, cool it down and crush it to obtain modified electrolytic waste particles; Step 2: Weigh 500g of modified electrolytic waste and add water according to the solid-liquid ratio of 1:2, place it at 50℃ and stir for 90min, after solid-liquid separation, add calcium oxide to the filtrate to remove impurities, filter and separate, and concentrate the filtrate to obtain a high-concentration lithium salt solution. Add sodium phosphate according to the lithium: phosphate molar ratio of 3:1.05 and react at 80℃ for 60min to obtain a lithium phosphate product; After testing, the purity of lithium phosphate is 90.54%; Step 3: adding sodium hydroxide solution to the filter residue obtained in step 2 at a solid-liquid ratio of 1: 5 and a filter residue: sodium hydroxide mass ratio of 1: 0.7 to carry out stirring reaction to obtain a mixed solution of sodium hydroxide, sodium metaaluminate and sodium fluoride; after washing with water 6 times, collecting and obtaining a sodium fluoride solution; Step 4: Add carbon dioxide to the mixed solution of step 3, adjust the solution pH to 10, separate the solid and liquid to obtain aluminum hydroxide and sodium carbonate solution; after testing, the aluminum content in aluminum hydroxide is 31.65%. The concentration of sodium carbonate is 130 g / L; the sodium carbonate solution is returned to step 2 to prepare lithium carbonate.

[0043] Step 5: preparing an ammonium fluoride solution by using an ion recombination device, wherein the activated carbon mass fraction in the activated carbon slurry is 20%; placing a saturated sodium fluoride solution and an ammonium bicarbonate solution in the first and second separation chambers; the flow rate of the first and second circulation systems is 20 ml / min; and the power supply voltage is 1.0 V; After testing, the fluoride ion concentration in the ammonium fluoride solution prepared by the ion recombination device was 15g / L; Step 6: According to the fluorine:aluminum molar ratio of 3.05:1, use ammonium fluoride solution to react with the aluminum hydroxide slurry prepared in step 4 to obtain ammonium fluoroaluminate precipitate, and then obtain aluminum fluoride product after roasting.

[0044] After testing, the fluorine content in the prepared aluminum fluoride was 59.43%, and the aluminum content was 29.57%, which met the national standard requirements for aluminum fluoride. Example 5

[0045] Example 5 A method for efficiently recovering aluminum electrolysis waste using ion recombination technology is basically the same as Example 2, except that: Replace aluminum ash with mullite, and the ratio of the three is changed to 1:0.3:0.6; The purity of the prepared lithium carbonate is 99.64, which meets the national standard requirements for battery-grade lithium carbonate; The activated carbon content was changed to 30%, the ammonium bicarbonate in the second separation chamber was changed to ammonium carbonate solution, and the applied voltage was changed to 2.0 V; After testing, the fluoride ion concentration in the prepared sodium fluoride solution was 20g / L, and the sodium carbonate solution concentration was 80g / L. The sodium carbonate was returned to the system for reuse; The prepared aluminum fluoride has a fluorine content of 60.21% and an aluminum content of 29.24%, which meets the national standard requirements for aluminum fluoride.

[0046] 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 using ion recombination technology, characterized in that: The following steps are involved: Step 1: crushing the aluminum electrolytic waste to be treated, fully mixing it with aluminum-containing waste and sulfuric acid, and then roasting and modifying it to obtain modified electrolytic waste; Step 2: crush the modified electrolytic waste material, mix with water, stir and react, and filter to obtain filter residue A and filtrate A; the filtrate A is filtered and concentrated after impurity removal, and a soluble carbonate or phosphate is added to carry out lithium precipitation reaction; Step 3: The filter residue A and the impurity-removing precipitate of the filtrate A obtained in step 2 are mixed with an alkaline solution to carry out an alkaline leaching reaction to obtain a mixed solution of sodium aluminate, sodium hydroxide and sodium fluoride; and the filter residue A is washed with water for multiple times to obtain a sodium fluoride solution; Step 4: introducing carbon dioxide into the mixed solution obtained in step 3 or using an acid solution to adjust the pH of the solution to 10-12 to obtain aluminum hydroxide precipitate and sodium carbonate / sodium salt solution; the sodium carbonate / sodium salt solution is returned to the system for recycling; Step 5: The sodium fluoride solution obtained in step 3 is reacted with ammonia water / ammonium salt solution using an ion recombination device to obtain an ammonium fluoride solution and a sodium hydroxide solution or a sodium salt; the ammonium fluoride solution is reacted with the aluminum hydroxide / aluminum salt prepared in step 3 to prepare high-purity aluminum fluoride, and the sodium hydroxide solution or the sodium salt is reused.

2. The method for efficiently recovering aluminum electrolysis waste using ion recombination technology 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 1 is one or more of aluminum ash, aluminum water and aluminum oxides in molten salt, limestone, coal ash, etc., aluminum scrap products, and waste slag in the aluminum processing process; the mass ratio of aluminum electrolysis waste: aluminum-containing waste: sulfuric acid in step 1 is 1:0.2-0.5:0.3-1.

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

6.

4. The method for efficiently recovering aluminum electrolysis waste using ion recombination technology according to claim 1, characterized in that: The soluble carbonate in step 2 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.

5. The method for efficiently recovering aluminum electrolysis waste using ion recombination technology according to claim 1, characterized in that: The alkaline solution used in step 3 is a sodium hydroxide solution, the mass ratio of leached residue A to sodium hydroxide is 1:0.5-1; the solid-liquid ratio is 1:3-20; and the number of water washings is 3-8 times.

6. The method for efficiently recovering aluminum electrolysis waste using ion recombination technology according to claim 1, characterized in that: The alkaline solution used in step 3 is a sodium hydroxide solution, the mass ratio of leached residue A to sodium hydroxide is 1:0.6-0.9; the solid-liquid ratio is 1:5-10; and the number of water washings is 4-6 times.

7. The method for efficiently recovering aluminum electrolysis waste using ion recombination technology according to claim 1, characterized in that: The ion recombination device in step 5 comprises a plurality of FCDI modules and a plurality of liquid storage tanks; the FCDI modules comprise a first FCDI module (1), a second FCDI module (2), a third FCDI module (3) and a fourth FCDI module (4); the liquid storage tanks comprise a first liquid storage tank (5), a second liquid storage tank (6), a third liquid storage tank (7), a fourth liquid storage tank (8), a fifth liquid storage tank (9) and a sixth liquid storage tank (10); the first FCDI module (1) is provided with a first cation exchange membrane (11) and a first anion exchange membrane (12); the first cation exchange membrane (11) and the first anion exchange membrane (12) divide the interior of the first FCDI module (1) into a first anode chamber, a first separation chamber and a first cathode chamber; the second FCDI module (2) is provided with a second cation exchange membrane (21) and a second anion exchange membrane (22); the second cation exchange membrane (21) and the second anion exchange membrane (22) divide the interior of the second FCDI module (1) into a first anode chamber, a first separation chamber and a first cathode chamber; The interior of the block (2) is divided into a second anode chamber, a second separation chamber and a second cathode chamber; the third FCDI module (3) is provided with a third cation exchange membrane (31) and a third anion exchange membrane (32); the third cation exchange membrane (31) and the third anion exchange membrane (32) divide the interior of the third FCDI module (3) into a third anode chamber, a third synthesis chamber and a third cathode chamber; the fourth FCDI module (4) is provided with a fourth cation exchange membrane (41) and a fourth anion exchange membrane (42); the fourth cation exchange membrane (41) and the fourth anion exchange membrane (42) divide the interior of the fourth FCDI module (4) into a fourth anode chamber, a fourth synthesis chamber and a fourth cathode chamber; the first liquid storage tank (5), the first anode chamber, the first cathode chamber, the third anode chamber and the fourth cathode chamber form a first circulation system via a pipeline; the second liquid storage tank (6), the second anode chamber, the second cathode chamber, the fourth anode chamber and the third cathode chamber form a second circulation system via a pipeline.

8. The method for efficiently recovering aluminum electrolysis waste using ion recombination technology according to claim 7, characterized in that: The first liquid storage tank (5) and the second liquid storage tank (6) respectively store activated carbon solutions, wherein the mass fraction of the solid phase carbon content of the activated carbon solutions is in the range of 5%-60%. The third liquid storage tank (7) stores the sodium fluoride solution prepared in step 3, wherein the mass concentration of the sodium fluoride solution is 10 g / L saturated concentration. The fourth liquid storage tank (8) stores ammonia water / ammonium salt solution, wherein the mass concentration of the ammonia water / ammonium salt solution is 10 g / L saturated concentration. The ammonium salt solution is specifically one or more of ammonium carbonate, ammonium bicarbonate, ammonium sulfate, ammonium chloride, etc. The fifth liquid storage tank (9) and the sixth liquid storage tank (10) are respectively used to store the sodium salt solution and the ammonium fluoride solution after ion reorganization.

9. The method for efficiently recovering aluminum electrolysis waste using ion recombination technology according to claim 7, characterized in that: In step 5, the sodium fluoride solution obtained in step 3 is reacted with ammonia water / ammonium salt solution using an ion recombination device, comprising the following steps: S51: a sodium fluoride solution and an ammonium salt solution with a mass concentration of 10 g / L are circulated in the first separation chamber and the second separation chamber respectively; an activated carbon slurry with a mass fraction range of 10%-60% is filled in the first liquid storage device and the second liquid storage device respectively; S52: Start the device to start the first circulation system circulation. When the activated carbon slurry passes through the first anode chamber and the first cathode chamber, under the action of the electric field, the anions and cations in the soluble carbonate solution in the first separation chamber are adsorbed by the carbon slurry through the anion and cation membrane. When the carbon slurry rich in anions and cations passes through the third anode chamber and the fourth cathode chamber, under the action of the opposite electric field, the anions and cations in the carbon slurry are desorbed into the third synthesis chamber and the fourth synthesis chamber through the anion and cation membrane. The third synthesis chamber receives cations, and the fourth synthesis chamber receives anions. The reaction temperature range of this process is controlled to be 10-50°C, the circulation flow rate range in the first circulation system is 5-60ml / min, and the power supply voltage range is 0.2-8V. S53: After the first circulation system is completed, the second circulation system is entered. When the activated carbon slurry passes through the second anode chamber and the second cathode chamber, under the action of the electric field, the anions and cations in the lithium salt solution in the second separation chamber are adsorbed by the carbon slurry through the anion and cation membrane. When the carbon slurry rich in anions and cations passes through the fourth anode chamber and the third cathode chamber, under the action of the opposite electric field, the anions and cations in the carbon slurry are desorbed into the fourth synthesis chamber and the third synthesis chamber through the anion and cation membrane. The fourth synthesis chamber receives cations, and the third synthesis chamber receives anions. The reaction temperature range of this process is controlled to be 10-50°C, the circulation flow rate range in the second circulation system is 5-60mL / min, and the power supply voltage range is 0.2-8V; S54: After the second circulation system is completed, anions and cations combine in the third synthesis chamber to form a sodium salt solution, and anions and cations combine in the fourth synthesis chamber to form an ammonium fluoride solution.

10. The method for efficiently recovering aluminum electrolysis waste using ion recombination technology according to claim 7, characterized in that: The molar ratio of the reaction between the ammonium fluoride solution prepared by the ion recombination device and the aluminum salt is 3:0.8-1.1.

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