Method for synergistically extracting key metal from waste lithium battery mixed waste
The waste lithium batteries are alloyed through mechanical force chemistry, combined with high-temperature thermodynamic reaction and ammonia reduction, and the selective extraction of lithium, nickel and cobalt is achieved, solving the problems of high-temperature metallurgy high energy consumption and large carbon footprint, and realizing metal recovery with low energy consumption and low carbon emissions.
Patent Information
- Application Number
- CN202310996977.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-08-09
- Publication Date
- 2025-02-25
AI Technical Summary
When the existing high-temperature metallurgy method extracts key metals from waste lithium batteries, it leads to a large amount of energy consumption and a high-density carbon footprint, making it difficult to achieve low carbon emissions and low energy consumption recycling.
Mechanical force chemistry method is used to alloy the mixed positive electrode material of waste lithium batteries, and the pyrolysis temperature is reduced through a planetary ball mill and high-temperature thermodynamic reaction, combined with ammonia reduction and extraction agent extraction, selective extraction of lithium, nickel and cobalt is achieved.
It significantly reduces the thermal reduction temperature and energy consumption, reduces carbon emissions, and realizes efficient recycling of key metals in waste lithium batteries, with good economic and environmental benefits.
Smart Images
Figure CN119506576A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a method for collaboratively extracting key metals from mixed battery waste, belonging to the technical field of industrial solid waste and electronic waste treatment and resource utilization. Background Art
[0002] Lithium-ion batteries are widely used in many areas of human life due to their excellent electrochemical cycle performance, high energy density, portability and low carbon emission density. As the global community begins to enter the era of electrification and decarbonization, the production and shipment of lithium-ion batteries that can be loaded in electric vehicles continue to rise. According to reliable estimates, their consumption will reach US$221 billion by 2045. After 6 to 8 years of recycling, lithium-ion batteries will eventually be scrapped, even after multiple recycling. It is estimated that the number of scrapped batteries will reach about 1 billion tons by 2030. Waste lithium batteries contain many valuable key metals and components, such as 5 to 20% cobalt, 5 to 10% nickel, 5 to 7% lithium and 15% organic electrolyte (lithium hexafluorophosphate). Due to the severe shortage of key metals such as lithium, nickel, and cobalt, as well as the environmental pollution problems that may be caused by heavy metals and electrolytes, the recycling of waste lithium batteries is imminent.
[0003] Currently, there are many technologies for recycling key metals in waste lithium batteries. The ultimate goal of these technologies is to close the metal circulation path and realize the closed flow of non-ferrous minerals in the electric vehicle industry chain. For example, lithium can be extracted from waste lithium batteries and converted into upstream lithium carbonate products through a series of chemical processes such as solvent extraction, ion exchange and evaporation crystallization. Cobalt and nickel are among the most valuable non-ferrous metals in retired lithium batteries and can be recovered through a combination of physical and chemical methods through a well-designed pathway. Regenerated cobalt and nickel can be used to manufacture new batteries or other products. In known industrial production and scientific research, pyrometallurgical and hydrometallurgical routes are regarded as the main technical approaches to achieve the separation and green circulation of important metals in waste lithium batteries.
[0004] However, despite the current many ways to dispose and regenerate waste lithium batteries, these studies still have certain limitations, that is, they are usually only effective recycling routes designed for a single battery type. At present, there are relatively few recycling routes for multi-source scrapped lithium batteries. The current technical gap poses a severe technical challenge to the selective extraction of key metals from multi-source waste materials. Due to the current chaos in the lithium battery recycling market, it is extremely difficult to collect, manage and recycle a single battery type or batteries of the same brand. In addition, in the current recycling pathways, high-temperature metallurgy, as a general method and strategy, usually uses a carbon source as a reducing agent to thermally reduce the high-valent cobalt and manganese in the nickel-cobalt-manganese phase at temperatures as high as 700-800 degrees, which will lead to a large amount of energy consumption and a high-density carbon footprint. Therefore, it is urgent to design a low-carbon and low-energy route that can selectively extract key metals lithium, nickel and cobalt from multi-source waste lithium battery waste. Summary of the invention
[0005] The purpose of the present invention is to solve the technical problem that high-temperature metallurgy uses a carbon source as a reducing agent, which leads to a large amount of energy consumption and a high-density carbon footprint at high temperature, and to provide a method for synergistically extracting key metals from mixed waste of used lithium batteries.
[0006] A method for synergistically extracting key metals from mixed waste of used lithium batteries is as follows: 1. Discharge the waste lithium batteries in a centralized manner, and then use crushing-sorting equipment to mix, crush, sort and classify the components in the waste lithium battery packs for recycling. The screened aluminum foil, copper foil and plastic or steel shell are used as secondary products. The mixed positive electrode material particle powder obtained by sorting is passed through a sieve to obtain a mixed positive electrode material powder of waste lithium batteries; 2. The waste lithium battery mixed positive electrode material powder obtained in step 1 is reacted in a zirconia ball mill of a planetary ball mill at a rotation speed of 600-1000 rpm for 6-24 h, the mixed positive electrode material powder is taken out and pressed into a large-scale tablet press at a pressure of 10-30 MPa, and the pressed tablet is placed in a high-temperature tubular furnace at 600-1100 degrees for high-temperature thermodynamic reaction for 2-4 h; 3. After the positive electrode material treated in step 2 is cooled to room temperature, deionized water is used to rinse and soak the pyrolysis sample, filtered, and the filtrate is evaporated to obtain a lithium carbonate product. The solid filter residue is then reduced with an ammonia method and stirred for leaching for 2 to 4 hours, and then filtered. The manganese and iron phosphate in the filter residue are sent to the landfill as worthless waste residue. The filtrate is extracted and backwashed with an extractant to separate nickel and cobalt, thereby completing the synergistic extraction of key metals from the mixed waste of waste lithium batteries.
[0007] The waste lithium battery described in step 1 is a combination of one or more of a lithium iron phosphate battery and a lithium cobalt oxide battery, a lithium manganese oxide battery and a nickel-cobalt-manganese ternary material power battery, and the molar ratio of high-valent metals (cobalt, nickel) in the lithium cobalt oxide battery and / or the nickel-cobalt-manganese ternary material power battery to low-valent metal iron in the lithium iron phosphate is 1:1~2:1.
[0008] The aperture of the sieve in step 1 is 160-400 mesh.
[0009] The ammonia reduction leaching solution in step 3 is ammonia water and one or a combination of several of ammonium sulfate, ammonium carbonate, ammonium bicarbonate, ammonium sulfite, ammonium persulfate and ammonium thiosulfate.
[0010] The extractant in step 3 is one or a combination of Cyanex 272, Cyanex 302, D2EHPA, APT6500, P204, P507, LIX84, P507 and 8-hydroxyquinoline.
[0011] Step 2: The mixed positive electrode material of waste lithium batteries contains nickel, cobalt and manganese, and the reaction temperature is 600~650 degrees; the mixed positive electrode material of waste lithium batteries contains lithium iron phosphate, and the reaction temperature is 850~950 degrees; the mixed positive electrode material of old lithium batteries contains lithium cobalt oxide, and the reaction temperature is 1000~1100 degrees.
[0012] The method of the present invention for synergistically extracting key metals from mixed waste materials of waste lithium batteries is widely applicable to different types of positive electrode materials of waste lithium batteries. For positive electrode material powders (which must include lithium iron phosphate materials) of different sources, different compositions and different metal contents, the method or technical route for synergistically extracting key metals from mixed waste materials of waste lithium batteries can be adopted to achieve the purpose of recovering key metals such as lithium, nickel and cobalt.
[0013] Waste lithium batteries mainly contain different types of positive electrode materials such as lithium cobalt oxide, lithium manganese oxide and ternary nickel cobalt manganese oxide. Among these materials, the valence of cobalt and manganese is usually high, that is, +3 or +4. Therefore, when recycling waste lithium batteries, a reducing agent must be added to promote the conversion of high-valent cobalt and manganese compounds into low-valent states. Graphite materials are often used as reducing agents in pyrometallurgy, but different types of positive electrode materials lead to significant differences in the reduction temperature of crystalline compounds. Normally, the thermodynamic reduction temperature of lithium cobalt oxide compounds is about 1100 degrees, while the reduction temperature of ternary nickel cobalt manganese oxide is about 700 degrees. Due to such a high thermodynamic reduction temperature, the energy consumption in the actual production process is high, which in turn leads to problems such as increased carbon emissions and rising production costs.
[0014] The use of mechanochemical methods to alloy the mixed positive electrode materials of waste lithium batteries can effectively reduce their pyrolysis temperature. The cooling principle is to achieve electronic complex transition and valence normalization between low-valence iron and high-valence cobalt / manganese elements through solid-phase reaction. At the same time, in the mixed positive electrode materials of waste lithium batteries, mechanical force is converted into internal energy and released during the thermodynamic reduction process, thereby significantly reducing the pyrolysis temperature. This process can effectively reduce reaction energy consumption and greenhouse gas emissions, bringing good economic and environmental benefits to actual production.
[0015] The present invention designs a method for synergistically extracting key metals from mixed waste materials of used lithium batteries. Through mechanochemical action, the reduced and oxidized metals in the multi-source mixed waste can undergo solid-phase reaction, resulting in the selective and preferential release of part of the lithium in the mixed waste. Subsequently, the lithium carbonate product is extracted by high-temperature thermodynamic reduction combined with water washing and evaporation technology. The secondary residue can be selectively extracted and effectively separated from nickel and cobalt by ammonia reduction leaching combined with solvent extraction. This method has good selectivity and can selectively extract key metals such as lithium, nickel and cobalt from multi-source waste lithium batteries in steps, which can significantly reduce the energy consumption of high-temperature thermodynamic reactions in the pyrometallurgical process and has good economic and environmental benefits. On the other hand, this method can reduce carbon emissions in the recycling process of used lithium batteries, which is beneficial to metal recovery and efficiency.
[0016] The method of the present invention extracts key metals lithium, nickel, cobalt and manganese from waste lithium batteries by means of coordinated processing. The designed route can reduce the reaction energy consumption of high-temperature thermodynamics and significantly reduce carbon emissions. The ammonia reduction leaching route adopted has excellent selectivity for the extraction of key metals lithium, nickel and cobalt, and the extraction process is short, which can realize the selective extraction of key metals in mixed waste materials of waste lithium batteries, and has significant economic and environmental benefits.
[0017] Compared with the prior art, the method of the present invention has strong compatibility with the sources of mixed waste from used lithium batteries, a short reaction process, and low reagent costs. It can significantly reduce the thermal reduction temperature of mixed waste from used lithium batteries, reduce the high-temperature energy consumption of the pyrolysis reaction, and has good economic and environmental benefits. On the other hand, the method can reduce carbon emissions during the recycling process of used lithium batteries, which is beneficial for metal recovery and efficiency. Under optimal conditions, the recovery efficiency of lithium, nickel, and cobalt using the method of the present invention for synergistic extraction of key metals from mixed waste from used lithium batteries can reach 92.5wt.%, 96.7wt.%, and 95.9wt.% or more. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 It is a flow chart of the method for synergistically extracting key metals from mixed waste materials of used lithium batteries according to the present invention; Figure 2This is the infrared spectrum comparison chart of the original mixed sample of waste lithium iron phosphate and ternary nickel-cobalt-manganese positive electrode material in Experiment 1 and the sample after high-temperature heat treatment (650 degrees). DETAILED DESCRIPTION
[0019] The technical solution of the present invention is not limited to the specific implementation modes listed below, but also includes any combination of the specific implementation modes.
[0020] Specific implementation method 1: In this implementation method, a method for synergistically extracting key metals from mixed waste materials of waste lithium batteries is as follows: 1. Discharge the waste lithium batteries in a centralized manner, and then use crushing-sorting equipment to mix, crush, sort and classify the components in the waste lithium battery packs for recycling. The screened aluminum foil, copper foil and plastic or steel shell are used as secondary products. The mixed positive electrode material particle powder obtained by sorting is passed through a sieve to obtain a mixed positive electrode material powder of waste lithium batteries; 2. The waste lithium battery mixed positive electrode material powder obtained in step 1 is reacted in a zirconia ball mill of a planetary ball mill at a rotation speed of 600-1000 rpm for 6-24 h, the mixed positive electrode material powder is taken out and pressed into a large-scale tablet press at a pressure of 10-30 MPa, and the pressed tablet is placed in a high-temperature tubular furnace at 600-1100 degrees for high-temperature thermodynamic reaction for 2-4 h; 3. After the positive electrode material treated in step 2 is cooled to room temperature, deionized water is used to rinse and soak the pyrolysis sample, filtered, and the filtrate is evaporated to obtain a lithium carbonate product. The solid filter residue is then reduced with an ammonia method and stirred for leaching for 2 to 4 hours, and then filtered. The manganese and iron phosphate in the filter residue are sent to the landfill as worthless waste residue. The filtrate is extracted and backwashed with an extractant to separate nickel and cobalt, thereby completing the synergistic extraction of key metals from the mixed waste of waste lithium batteries.
[0021] Specific implementation method 2: This implementation method is different from specific implementation method 1 in that the waste lithium battery in step 1 is a combination of one or more of a lithium iron phosphate battery and a lithium cobalt oxide battery, a lithium manganese oxide battery, and a nickel-cobalt-manganese ternary material power battery, and the molar ratio of high-valent metals (cobalt, nickel) in the lithium cobalt oxide battery and / or the nickel-cobalt-manganese ternary material power battery to low-valent metal iron in the lithium iron phosphate is 1:1 to 2:1. The rest is the same as specific implementation method 1.
[0022] Specific implementation method 3: This implementation method is different from specific implementation method 1 or 2 in that the aperture of the sieve in step 1 is 160-400 meshes. The rest is the same as specific implementation method 1 or 2.
[0023] Specific embodiment 4: This embodiment is different from specific embodiments 1 to 3 in that the ammonia reduction leaching solution in step 3 is ammonia water and one or a combination of ammonium sulfate, ammonium carbonate, ammonium bicarbonate, ammonium sulfite, ammonium persulfate and ammonium thiosulfate. The rest is the same as specific embodiments 1 to 3.
[0024] Specific embodiment 5: This embodiment is different from specific embodiments 1 to 4 in that the extractant in step 3 is one or a combination of Cyanex 272, Cyanex 302, D2EHPA, APT6500, P204, P507, LIX84, P507 and 8-hydroxyquinoline. The rest is the same as specific embodiments 1 to 4.
[0025] Specific embodiment 6: This embodiment is different from specific embodiments 1 to 5 in that in step 2, the mixed positive electrode material of waste lithium batteries contains nickel, cobalt and manganese, and the reaction temperature is 600-650 degrees; the mixed positive electrode material of waste lithium batteries contains lithium iron phosphate, and the reaction temperature is 850-950 degrees; the mixed positive electrode material of old lithium batteries contains lithium cobalt oxide, and the reaction temperature is 1000-1100 degrees. The rest is the same as specific embodiments 1 to 5.
[0026] The following experiments are only listed as examples of embodiments of the present invention and do not constitute any limitation to the present invention. It can be understood by those skilled in the art that modifications within the scope of the essence and concept of the present invention fall within the scope of protection of the present invention. Unless otherwise specified, the reagents and instruments used in the following experiments are commercially available products.
[0027] The following experiments were used to verify the effect of the present invention: Experiment 1: A method for synergistically extracting key metals from mixed waste of used lithium batteries is as follows: 1. Discharge the waste lithium batteries in a self-made series lighting device to avoid possible explosion or spontaneous combustion of the batteries during the disassembly process. Then, crushing-sorting equipment is used to mix, crush, sort and classify the components in the waste lithium battery packs for recycling. The aluminum foil, copper foil and plastic or steel shell obtained by screening are used as secondary products. The mixed positive electrode material particle powder obtained by sorting is passed through a sieve with an aperture of 200 mesh to obtain the waste lithium battery mixed positive electrode material powder; 2. The waste lithium battery mixed positive electrode material powder obtained in step 1 was reacted in a zirconia ball mill of a planetary ball mill at a speed of 600 rpm for 12 h, the mixed positive electrode material powder was taken out and pressed into a large tablet press at a pressure of 15 MPa, and the pressed tablet was placed in a high-temperature tubular furnace at 700 degrees for a high-temperature thermodynamic reaction for 2 h; 3. After the positive electrode material treated in step 2 is cooled to room temperature, it is rinsed with deionized water, soaked in pyrolysis samples, filtered, and the filtrate is evaporated to obtain lithium carbonate products. Then, the solid filter residue is reduced by ammonia and stirred for leaching for 2 hours to dissolve the residual cobalt, nickel and manganese oxides, wherein nickel and cobalt enter the leaching solution, while iron and manganese enter the residue phase, and then filtered. Manganese and iron phosphate in the filter residue are treated as worthless waste residues in the landfill. The filtrate is extracted and backwashed with an extractant to separate nickel and cobalt, thus completing the synergistic extraction of key metals from the mixed waste of waste lithium batteries. Finally, the gains of lithium, nickel and cobalt were 92.1wt.%, 93.1wt.% and 94.3wt.%, respectively.
[0028] The waste lithium battery in step 1 is a combination of a lithium iron phosphate battery and a nickel-cobalt-manganese ternary material power battery. The molar ratio of high-valent metal cobalt and nickel in the nickel-cobalt-manganese ternary material power battery to low-valent metal iron in the lithium iron phosphate is 1.2:1.
[0029] The ammonia reduction leaching solution in step 3 is a combination of aqueous ammonia and ammonium sulfite in any ratio.
[0030] The extractant in step 3 is APT6500.
[0031] Figure 1 This is a flow chart of the recovery of key metals such as lithium, nickel and cobalt from the mixed materials of waste lithium batteries in Experiment 1 through crushing and sorting, mechanochemical reaction, high-temperature thermodynamic reduction and ammonia reduction leaching.
[0032] Figure 2 The results show that FeO6 and PO4 as well as PO4 can be observed in the original mixed samples of waste lithium iron phosphate and ternary nickel-cobalt-manganese positive electrode materials. 3- After high-temperature heat treatment, these characteristic bands disappeared, confirming the release of lithium in the lithium iron phosphate sample.
[0033] Experiment 2: A method for synergistically extracting key metals from mixed waste of used lithium batteries is as follows: 1. Discharge the waste lithium batteries in a self-made series lighting device to avoid possible explosion or spontaneous combustion of the batteries during the disassembly process. Then, crushing-sorting equipment is used to mix, crush, sort and classify the components in the waste lithium battery packs for recycling. The aluminum foil, copper foil and plastic or steel shell obtained by screening are used as secondary products. The mixed positive electrode material particle powder obtained by sorting is passed through a sieve with an aperture of 200 mesh to obtain the waste lithium battery mixed positive electrode material powder; 2. The waste lithium battery mixed positive electrode material powder obtained in step 1 was reacted in a zirconia ball mill of a planetary ball mill at a speed of 800 rpm for 6 h, the mixed positive electrode material powder was taken out and tableted in a large tablet press at a pressure of 10 MPa, and the tablets were placed in a high-temperature tubular furnace at 800 degrees for high-temperature thermodynamic reaction for 2 h; 3. After the positive electrode material treated in step 2 is cooled to room temperature, it is rinsed with deionized water, soaked in pyrolysis samples, filtered, and the filtrate is evaporated to obtain lithium carbonate products. Then, the solid filter residue is reduced by ammonia method and stirred for leaching for 3 hours to achieve the dissolution of residual cobalt, nickel and manganese oxides, wherein nickel and cobalt enter the leaching solution, while iron and manganese enter the residue phase, and then filtered. Manganese and iron phosphate in the filter residue are treated as worthless waste residues in the landfill. The filtrate is extracted and backwashed with an extractant to separate nickel and cobalt, thus completing the synergistic extraction of key metals from the mixed waste of waste lithium batteries. Finally, the gains of lithium, nickel and cobalt were 93.2wt.%, 91.7wt.% and 92.7wt.%, respectively.
[0034] The waste lithium battery described in step 1 is a combination of a lithium iron phosphate battery and a nickel-cobalt-manganese ternary material power battery. The molar ratio of high-valent metal cobalt and nickel in the nickel-cobalt-manganese ternary material power battery to low-valent metal iron in the lithium iron phosphate is 1.2: 1. The ammonia reduction leaching solution described in step 3 is a combination of ammonia water and ammonium sulfite in any ratio.
[0035] The extractant in step 3 is P507.
[0036] Experiment 3: A method for synergistically extracting key metals from mixed waste of used lithium batteries is as follows: 1. Discharge the waste lithium batteries in a centralized manner to avoid possible explosion or spontaneous combustion during the disassembly process. Then, crushing-sorting equipment is used to mix, crush, sort and classify the components in the waste lithium battery packs for recycling. The screened aluminum foil, copper foil and plastic or steel shell are used as secondary products. The mixed positive electrode material particle powder obtained by sorting is passed through a 200-mesh sieve to obtain the waste lithium battery mixed positive electrode material powder; 2. The waste lithium battery mixed positive electrode material powder obtained in step 1 was reacted in a zirconia ball mill of a planetary ball mill at a speed of 700 rpm for 6 h, the mixed positive electrode material powder was taken out and tableted in a large tablet press at a pressure of 10 MPa, and the tablets were placed in a high-temperature tubular furnace at 750 degrees for high-temperature thermodynamic reaction for 2 h; 3. After the positive electrode material treated in step 2 is cooled to room temperature, it is rinsed with deionized water, soaked in pyrolysis samples, filtered, and the filtrate is evaporated to obtain lithium carbonate products. Then, the solid filter residue is immersed in ammonia reduction leaching solution and stirred for 4 hours to dissolve the residual cobalt, nickel and manganese oxides, wherein nickel and cobalt enter the leaching solution, while iron and manganese enter the residue phase, and then filtered. Manganese and iron phosphate in the filter residue are treated as worthless waste residues in the landfill. The filtrate is extracted and backwashed with an extractant to separate nickel and cobalt, thus completing the synergistic extraction of key metals from the mixed waste of waste lithium batteries. Finally, the gains of lithium, nickel and cobalt were 92.8wt.%, 91.6wt.% and 95.2wt.%, respectively.
[0037] The waste lithium battery in step 1 is a combination of a lithium iron phosphate battery and a nickel-cobalt-manganese ternary material power battery. The molar ratio of high-valent metal cobalt and nickel in the nickel-cobalt-manganese ternary material power battery to low-valent metal iron in the lithium iron phosphate is 1.2:1.
[0038] The ammonia reduction leaching solution in step 3 is a combination of aqueous ammonia and ammonium sulfite in any ratio.
[0039] The extractant in step 3 is P507.
[0040] Experiment 4: A method for synergistically extracting key metals from mixed waste of used lithium batteries is as follows: 1. Discharge the waste lithium batteries in a centralized manner to avoid possible explosion or spontaneous combustion during the disassembly process. Then, crushing-sorting equipment is used to mix, crush, sort and classify the components in the waste lithium battery packs for recycling. The screened aluminum foil, copper foil and plastic or steel shell are used as secondary products. The mixed positive electrode material particle powder obtained by sorting is passed through a 200-mesh sieve to obtain the waste lithium battery mixed positive electrode material powder; 2. The waste lithium battery mixed positive electrode material powder obtained in step 1 was reacted in a zirconia ball mill of a planetary ball mill at a speed of 700 rpm for 12 h, the mixed positive electrode material powder was taken out and tableted in a large tablet press at a pressure of 10 MPa, and the tablets were placed in a high-temperature tubular furnace at 750 degrees for high-temperature thermodynamic reaction for 2 h; 3. After the positive electrode material treated in step 2 is cooled to room temperature, it is rinsed with deionized water, soaked in pyrolysis samples, filtered, and the filtrate is evaporated to obtain lithium carbonate products. Then, the solid filter residue is reduced by ammonia and stirred for leaching for 4 hours to dissolve the residual cobalt, nickel and manganese oxides, wherein nickel and cobalt enter the leaching solution, while iron and manganese enter the residue phase, and then filtered. Manganese and iron phosphate in the filter residue are treated as worthless waste residues in the landfill. The filtrate is extracted and backwashed with an extractant to separate nickel and cobalt, thus completing the synergistic extraction of key metals from the mixed waste of waste lithium batteries. Finally, the gains of lithium, nickel and cobalt were 91.8wt.%, 91.9wt.% and 92.9wt.%, respectively.
[0041] The waste lithium battery in step 1 is a combination of a lithium iron phosphate battery and a nickel-cobalt-manganese ternary material power battery. The molar ratio of high-valent metal cobalt and nickel in the nickel-cobalt-manganese ternary material power battery to low-valent metal iron in the lithium iron phosphate is 1.2:1.
[0042] The ammonia reduction leaching solution in step 3 is a combination of aqueous ammonia and ammonium sulfite in any ratio.
[0043] The extractant in step 3 is APT6500.
[0044] From the results of Experiments 1 to 4, it can be seen that the method according to the present invention can achieve the selective extraction and recovery of key metal lithium, nickel and cobalt in mixed waste of waste lithium batteries with low energy consumption, low carbon emissions and high efficiency, thereby increasing the benefits and efficiency of the recycling process of such batteries.
Claims
1. A method for synergistically extracting key metals from mixed waste of used lithium batteries, characterized in that The method for synergistically extracting key metals from mixed waste of used lithium batteries is as follows:
1. Discharge the waste lithium batteries in a centralized manner, and then use crushing-sorting equipment to mix, crush, sort and classify the components in the waste lithium battery packs for recycling. The screened aluminum foil, copper foil and plastic or steel shell are used as secondary products. The mixed positive electrode material particle powder obtained by sorting is passed through a sieve to obtain a mixed positive electrode material powder of waste lithium batteries; 2. The waste lithium battery mixed positive electrode material powder obtained in step 1 is reacted in a zirconia ball mill of a planetary ball mill at a rotation speed of 600-1000 rpm for 6-24 h, the mixed positive electrode material powder is taken out and pressed into a large-scale tablet press at a pressure of 10-30 MPa, and the pressed tablet is placed in a high-temperature tubular furnace at 600-1100 degrees for high-temperature thermodynamic reaction for 2-4 h; 3. After the positive electrode material treated in step 2 is cooled to room temperature, deionized water is used to rinse and soak the pyrolysis sample, filtered, and the filtrate is evaporated to obtain a lithium carbonate product. The solid filter residue is then reduced with an ammonia method and stirred for leaching for 2 to 4 hours, and then filtered. The manganese and iron phosphate in the filter residue are sent to the landfill as worthless waste residue. The filtrate is extracted and backwashed with an extractant to separate nickel and cobalt, thereby completing the synergistic extraction of key metals from the mixed waste of waste lithium batteries.
2. A method for synergistically extracting key metals from mixed waste of waste lithium batteries according to claim 1, characterized in that The waste lithium battery described in step 1 is a combination of one or more of a lithium iron phosphate battery and a lithium cobalt oxide battery, a lithium manganese oxide battery and a nickel-cobalt-manganese ternary material power battery, and the molar ratio of high-valent metals in the lithium cobalt oxide battery and / or the nickel-cobalt-manganese ternary material power battery to low-valent metallic iron in the lithium iron phosphate is 1:1~2:
1.
3. A method for synergistically extracting key metals from mixed waste of used lithium batteries according to claim 1, characterized in that The aperture of the sieve in step 1 is 160-400 mesh.
4. A method for synergistically extracting key metals from mixed waste of used lithium batteries according to claim 1, characterized in that The ammonia reduction leaching solution in step 3 is ammonia water and one or a combination of several of ammonium sulfate, ammonium carbonate, ammonium bicarbonate, ammonium sulfite, ammonium persulfate and ammonium thiosulfate.
5. A method for synergistically extracting key metals from mixed waste of used lithium batteries according to claim 1, characterized in that The extractant in step 3 is one or a combination of Cyanex 272, Cyanex 302, D2EHPA, APT6500, P204, P507, LIX84, P507 and 8-hydroxyquinoline.
6. A method for synergistically extracting key metals from mixed waste of used lithium batteries according to claim 1, characterized in that Step 2: The mixed positive electrode material of waste lithium batteries contains nickel, cobalt and manganese, and the reaction temperature is 600~650 degrees; the mixed positive electrode material of waste lithium batteries contains lithium iron phosphate, and the reaction temperature is 850~950 degrees; the mixed positive electrode material of old lithium batteries contains lithium cobalt oxide, and the reaction temperature is 1000~1100 degrees.