A method for extracting metals from spent lithium-ion battery cathode materials

Abstract

The application discloses a method for extracting metal from waste lithium ion battery positive electrode material. It relates to the technical field of battery recycling. The method comprises the following five steps: (1) obtaining waste lithium ion battery positive electrode material; (2) mixing the waste lithium ion battery positive electrode material obtained in step (1) with an additive to obtain a mixture; (3) roasting the mixture obtained in step (2) to obtain a roasting product; (4) leaching the roasting product obtained in step (3) with deionized water; (5) after the process of step (4) is completed, filtering is performed to obtain a filtrate and a residue; wherein the filtrate is pyrolyzed, and the pyrolysis liquid is subjected to solid-liquid separation to obtain a lithium carbonate product; wherein the residue is leached with a mixed solution of sulfuric acid and oxalic acid, and the leaching liquid is purified and extracted to prepare nickel, cobalt and manganese products. The method has the advantages of easy operation, low roasting process temperature, low recovery cost and no secondary pollutants generated in the recovery process.

Description

Technical Field

[0001] This invention relates to the field of waste lithium-ion battery recycling technology, specifically a method for extracting metals from the cathode material of waste lithium-ion batteries. Background Technology

[0002] The growth in the production and sales of new energy vehicles has driven a significant year-on-year increase in lithium-ion battery production. Generally, the lifespan of lithium-ion batteries for new energy passenger vehicles is 5-6 years, while in the 3C (computer, communication, and consumer electronics) sector, they may only last 2-3 years before needing to be scrapped. Waste lithium-ion batteries contain a large amount of valuable metals, with lithium, cobalt, and nickel being the most valuable. Therefore, the resource-based recycling and utilization of waste lithium-ion batteries is of great significance for promoting the sustainable development of related industries.

[0003] Publicly reported methods for recycling waste lithium-ion batteries include: Zhou Mingxian et al. reported in *Chemical Industry and Engineering Progress*, Vol. 43, No. 4, 2024, 2174-2182, that lithium extraction from waste lithium-ion batteries is preferentially achieved through carbothermal reduction. Under optimal treatment conditions, the lithium leaching rate can reach 96.31%, while the leaching rates of cobalt, nickel, and manganese are all less than 0.1%. Patent [CN202410842782.7] reports a method for recycling waste lithium-ion batteries through sulfidation roasting. Lithium carbonate is produced through mixing and grinding + sulfidation roasting + leaching solid-liquid separation + precipitation reaction. After separating lithium and cobalt in the cathode material, a high-performance cathode material is resynthesized. Peng Teng et al. reported in *Hydrometallurgy*, Vol. 40, No. 3, 2021, 196-201, that cobalt is recovered from waste mobile phone lithium-ion batteries using a citric acid leaching-electrodeposition process. Patent [CN202410467943.9] reports a method for selectively recovering valuable metals from waste lithium-ion batteries. This method utilizes small-molecule organic acids generated by the oxidation of a selective extractant in a hydrothermal environment to achieve selective extraction of lithium, nickel, cobalt, and manganese. Patent [CN202410186705.0] reports a method for recovering lithium carbonate from waste lithium-ion batteries. The waste lithium-ion batteries are pretreated to obtain electrode powder, which is then mixed with a reduced biomass carbon quantum dot solution for granulation. A staged high-temperature thermal reduction process is used to reduce the metal ions in the cathode material to a low-valence, easily soluble state. Lithium carbonate is further recovered through processes such as acid leaching, alkali removal, and sodium carbonate precipitation. Patent [CN202310640477.5] discloses a method for recovering metals from waste lithium-ion battery cathode materials. The method involves high-temperature pretreatment of waste lithium-ion battery cathode sheets, mixing waste lithium-ion battery cathode powder with a leaching agent, and simultaneously applying ultraviolet irradiation. After filtration and washing, a metal leachate is obtained. Patent [CN201811066427.6] discloses a method for treating ternary lithium nickel cobalt manganese oxide waste. The ternary waste is dissolved with alkali, reduced, and dissolved in hot water to obtain lithium hydroxide, achieving separation between lithium and nickel, cobalt, and manganese. Patent [CN202310370070.5] reports a method for selective lithium extraction and clean utilization of all components from waste lithium-ion battery black powder. This method involves uniformly mixing waste lithium-ion battery black powder with sulfides and then calcining at high temperature. The calcined product is then leached with water and separated into solid and liquid components to obtain a lithium-containing leachate and filter residue. The lithium-containing leachate is then precipitated to obtain lithium carbonate.

[0004] Currently reported methods for recycling waste lithium-ion batteries include acid leaching, which generates a large amount of waste liquid containing waste acid and organic waste, resulting in high costs for harmless treatment; and carbon reduction, which requires high calcination temperatures for the reduction reaction, leading to high energy consumption and high recycling costs. Summary of the Invention

[0005] The purpose of this invention is to provide a method for extracting metals from the cathode material of waste lithium-ion batteries, in order to solve the problems of high cost of harmless treatment caused by the generation of acidic and organic waste liquid and high energy consumption and high recycling cost of carbon reduction recovery in current waste lithium-ion battery recycling methods.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A method for extracting metals from waste lithium-ion battery cathode materials includes the following steps: (1) Obtain cathode materials from waste lithium-ion batteries; (2) The waste lithium-ion battery cathode material obtained in step (1) is thoroughly mixed with the additives at a mass ratio of 1:0.05-4.5 to obtain a mixture; (3) The mixture obtained in step (2) is calcined at 200-600℃ for 0.5-3.5h to obtain the calcined product; (4) The calcined product obtained in step (3) is leached with deionized water at a solid-liquid ratio of 1:10-25. During the leaching process, the mixture is stirred, the temperature is controlled, and a solution with a purity ≥99.9% is introduced into the water. The process lasts 1-3 hours. (5) After the process described in step (4) is completed, filtration is performed to obtain filtrate and filter residue; The filtrate is heated to 80-100℃ for pyrolysis for 1-3 hours. After pyrolysis, the pyrolysis solution is subjected to solid-liquid separation to obtain lithium carbonate product. The filter residue is leached with a mixed solution of sulfuric acid and oxalic acid for 0.5-3 hours. After leaching, a leachate containing nickel, cobalt and manganese ions is obtained. The leachate is then purified and extracted to produce nickel, cobalt and manganese products.

[0007] Furthermore, in step (1), the sources of the waste lithium-ion battery cathode material include: cathode waste obtained after dismantling, crushing, sorting, screening, and flotation separation of collected waste lithium-ion batteries; cathode waste obtained after crushing, sorting, screening, and flotation separation of cathode scraps generated during the lithium-ion battery production process; cathode waste generated during the research and production of lithium-ion battery cathode materials; or a mixture of the above three cathode wastes in any combination.

[0008] Further, in step (1), the waste lithium-ion battery cathode material includes a mixture of one or more substances selected from lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, nickel-cobalt binary, nickel-manganese binary, cobalt-manganese binary, nickel-cobalt-manganese ternary, nickel-cobalt-aluminum ternary materials, and lithium-rich manganese-based layered oxide cathode materials.

[0009] Further, in step (2), the additive is one or more of the following substances: manganese carbonate, cobalt carbonate, nickel carbonate, manganese oxalate, cobalt oxalate, nickel oxalate, oxalic acid, sodium oxalate, potassium oxalate, ammonium oxalate, basic manganese carbonate, basic cobalt carbonate, basic nickel carbonate, sodium bicarbonate, potassium bicarbonate, ammonium bicarbonate, and ammonium carbonate.

[0010] Further, in step (2), the additive is a mixture formed by fully mixing one or more of the following substances: manganese carbonate, cobalt carbonate, nickel carbonate, manganese oxalate, cobalt oxalate, nickel oxalate, oxalic acid, sodium oxalate, potassium oxalate, ammonium oxalate, basic manganese carbonate, basic cobalt carbonate, basic nickel carbonate, sodium bicarbonate, potassium bicarbonate, ammonium bicarbonate, and ammonium carbonate with one or more of the following substances: metallic manganese powder, metallic nickel powder, metallic cobalt powder, and metallic aluminum powder.

[0011] Furthermore, in step (4), the stirring rate is 300-500 r / min, the temperature is 10-30℃, and the liquid surface... Partial pressure 0.2-1.2 MPa ventilation rate .

[0012] Further, in step (5), the initial concentration of sulfuric acid in the leachate is 1.0-1.5 mol / L, the initial concentration of oxalic acid is 0.3-0.6 mol / L, the solid-liquid ratio is 1:6-10, the reaction temperature is 50-80℃, and the stirring rate is 300-600 r / min.

[0013] The beneficial effects of the present invention: Based on research findings, the present invention has developed a new recycling method by pyrolyzing the additive at low temperature to induce chemical transformation of waste lithium-ion battery cathode materials and by considering the chemical characteristics and reaction mechanism of lithium and transition metal elements existing in different forms. In step (2), both the waste lithium-ion battery cathode materials and the additive are solid powder materials and are not flammable, explosive, or have special odors. Mixing the two evenly and loading them into the container simplifies the operation. In step (3), the roasting temperature is in the range of 200-600℃, which is significantly lower than the reported temperature in the background art. This reduces the recycling temperature and simplifies the operation, effectively reducing energy consumption and operating costs during the recycling process. In steps (3), (4), and (5), which are important links in the patent technology of the present invention, no polluting gases, wastewater, or solid waste that must be discharged into the environment are generated. The recycling process does not generate secondary pollutants and does not increase environmental protection costs. Attached Figure Description

[0014] Figure 1 This is a process flow diagram of the present invention. Detailed Implementation

[0015] like Figure 1 As shown, a method for extracting metals from waste lithium-ion battery cathode materials includes the following five steps.

[0016] (1) Obtaining waste lithium-ion battery cathode materials; the sources of the waste lithium-ion battery cathode materials include: cathode waste obtained after dismantling, crushing, sorting, screening, and flotation separation of collected scrap lithium-ion batteries; cathode waste obtained after crushing, sorting, screening, and flotation separation of cathode scraps generated during the lithium-ion battery production process; cathode waste generated during the research and production of lithium-ion battery cathode materials; or a mixture of the above three cathode wastes in any combination. The waste lithium-ion battery cathode materials include a mixture of one or more substances selected from lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, nickel-cobalt binary, nickel-manganese binary, cobalt-manganese binary, nickel-cobalt-manganese ternary, nickel-cobalt-aluminum ternary materials, and lithium-rich manganese-based layered oxide cathode materials.

[0017] (2) The waste lithium-ion battery cathode material obtained in step (1) is thoroughly mixed with additives at a mass ratio of 1:0.05-4.5 to obtain a mixture; the additives are one or more substances selected from manganese carbonate, cobalt carbonate, nickel carbonate, manganese oxalate, cobalt oxalate, nickel oxalate, oxalic acid, sodium oxalate, potassium oxalate, ammonium oxalate, basic manganese carbonate, basic cobalt carbonate, basic nickel carbonate, sodium bicarbonate, potassium bicarbonate, ammonium bicarbonate, and ammonium carbonate. The additives may also be one or more substances selected from manganese carbonate, cobalt carbonate, nickel carbonate, manganese oxalate, cobalt oxalate, nickel oxalate, oxalic acid, sodium oxalate, potassium oxalate, ammonium oxalate, basic manganese carbonate, basic cobalt carbonate, basic nickel carbonate, sodium bicarbonate, potassium bicarbonate, ammonium bicarbonate, and ammonium carbonate, and one or more substances selected from manganese powder, nickel powder, cobalt powder, and aluminum powder to form a mixture.

[0018] (3) The mixture obtained in step (2) is calcined at 200-600℃ for 0.5-3.5h to obtain the calcined product.

[0019] (4) The calcined product obtained in step (3) is leached with deionized water at a solid-liquid ratio of 1:10-25. During the leaching process, the mixture is stirred, the temperature is controlled, and a solution with a purity ≥99.9% is introduced into the water. Stirring rate 300-500 r / min, temperature 10-30℃, liquid surface Partial pressure 0.2-1.2 MPa ventilation rate The process lasts 1-3 hours.

[0020] (5) After the process described in step (4) is completed, filtration is performed to obtain filtrate and filter residue; The filtrate is heated to 80-100℃ for pyrolysis for 1-3 hours. After pyrolysis, the pyrolysis solution is subjected to solid-liquid separation to obtain lithium carbonate product. The filter residue is leached with a mixed solution of sulfuric acid and oxalic acid. The initial concentration of sulfuric acid in the leachate is 1.0-1.5 mol / L, the initial concentration of oxalic acid is 0.3-0.6 mol / L, the solid-liquid ratio is 1:6-10, the reaction temperature is 50-80℃, the stirring rate is 300-600 r / min, and the leaching time is 0.5-3 h. After leaching, a leachate containing nickel, cobalt, and manganese ions is obtained. The leachate is then purified and extracted to produce nickel, cobalt, and manganese products.

[0021] Example 1: Waste lithium-ion batteries using lithium nickel cobalt manganese oxide as the cathode material were collected. The cathode material obtained after crushing and dismantling was thoroughly mixed with manganese carbonate at a mass ratio of 1:2 to form a mixture. This mixture was then calcined at 500℃ for 1.5 hours. The calcined product was then leached with deionized water under conditions of high-purity CO2 (purity ≥99.9%). The leaching process was as follows: solid-liquid ratio 1:20 (g / mL), stirring speed 400 r / min, temperature 20℃, CO2 partial pressure at the liquid surface 0.5 MPa, and CO2 aeration rate 0.6 m / s. 3 / (h·m 3 The reaction solution was used for leaching, which lasted for 2.5 hours, achieving a lithium leaching rate of 90%. After leaching, the solution was filtered, and the filtrate was heated to 85°C for pyrolysis for 2 hours. After pyrolysis, the pyrolysis solution was filtered to obtain lithium carbonate. The filter residue obtained from the water leaching process was leached with a mixed solution of sulfuric acid and oxalic acid. The initial concentration of sulfuric acid in the leaching solution was 1.0 mol / L, the initial concentration of oxalic acid was 0.6 mol / L, the solid-liquid ratio was 1:7 (g / mL), the reaction temperature was 70°C, the stirring rate was 300 r / min, and the leaching time was 2 hours. The leaching solution obtained contained nickel, cobalt, and manganese ions, with leaching rates of 99% for all three. After purification and extraction, the leaching solution could be used to produce nickel sulfate, cobalt sulfate, and manganese sulfate.

[0022] Example 2: Waste lithium-ion batteries using lithium nickel cobalt manganese oxide as the cathode material were collected. The cathode material obtained after crushing and dismantling was mixed thoroughly with manganese carbonate at a mass ratio of 1:2 to form a mixture. This mixture was then calcined at 350℃ for 1 hour. The calcined product was then leached with deionized water under conditions of high-purity CO2 (purity ≥99.9%). The leaching process was as follows: solid-liquid ratio 1:20 (g / mL), stirring speed 400 r / min, temperature 20℃, CO2 partial pressure at the liquid surface 0.5 MPa, and CO2 aeration rate 0.6 m / s. 3 / (h·m 3The reaction solution was used for leaching, which lasted for 2.5 hours, resulting in a lithium leaching rate of 40%. After leaching, the solution was filtered, and the filtrate was heated to 85°C for pyrolysis for 2 hours. After pyrolysis, the pyrolysis solution was filtered to obtain lithium carbonate. The filter residue obtained from the water leaching process was leached with a mixed solution of sulfuric acid and oxalic acid. The initial concentration of sulfuric acid in the leaching solution was 1.0 mol / L, the initial concentration of oxalic acid was 0.6 mol / L, the solid-liquid ratio was 1:7 (g / mL), the reaction temperature was 70°C, the stirring rate was 300 r / min, and the leaching time was 2 hours. The leaching solution contained nickel, cobalt, and manganese ions, with leaching rates of 99% for all three. After purification and extraction, the leaching solution could be used to produce nickel sulfate, cobalt sulfate, and manganese sulfate.

[0023] Example 3: Waste lithium-ion batteries using lithium nickel cobalt manganese oxide as the cathode material were collected. The cathode material obtained after crushing and dismantling was thoroughly mixed with manganese carbonate and metallic manganese powder at a mass ratio of 1:1.5:0.1 to form a mixture. This mixture was then calcined at 500℃ for 1 hour. The calcined product was then leached with deionized water under conditions of high-purity CO2 (purity ≥99.9%). The leaching process was as follows: solid-liquid ratio 1:20 (g / mL), stirring speed 400 r / min, temperature 15℃, CO2 partial pressure at the liquid surface 0.5 MPa, and CO2 aeration rate 0.6 m / s. 3 / (h·m 3 The reaction solution was used for leaching, which lasted for 2.5 hours, resulting in a lithium leaching rate of 92%. After leaching, the solution was filtered, and the filtrate was heated to 85°C for pyrolysis for 2 hours. After pyrolysis, the pyrolysis solution was filtered to obtain lithium carbonate. The filter residue obtained from the water leaching process was leached with a mixed solution of sulfuric acid and oxalic acid. The initial concentration of sulfuric acid in the leaching solution was 1.0 mol / L, the initial concentration of oxalic acid was 0.6 mol / L, the solid-liquid ratio was 1:7 (g / mL), the reaction temperature was 70°C, the stirring rate was 300 r / min, and the leaching time was 2 hours. The leaching solution contained nickel, cobalt, and manganese ions, with leaching rates of 99% for all three. After purification and extraction, the leaching solution could be used to produce nickel sulfate, cobalt sulfate, and manganese sulfate.

[0024] Example 4: Waste lithium-ion batteries using lithium nickel cobalt manganese oxide as the cathode material were collected. The cathode material obtained after crushing and dismantling was thoroughly mixed with manganese carbonate and metallic manganese powder at a mass ratio of 1:1.3:0.15 to form a mixture. This mixture was then calcined at 500℃ for 1 hour. The calcined product was then leached with deionized water under conditions of high-purity CO2 (purity ≥99.9%). The leaching process was as follows: solid-liquid ratio 1:20 (g / mL), stirring speed 400 r / min, temperature 20℃, CO2 partial pressure at the liquid surface 0.5 MPa, and CO2 aeration rate 0.6 m / s. 3 / (h·m 3 The reaction solution was used for leaching, which lasted for 2.5 hours, achieving a lithium leaching rate of 93%. After leaching, the solution was filtered, and the filtrate was heated to 85°C for pyrolysis for 2 hours. After pyrolysis, the pyrolysis solution was filtered to obtain lithium carbonate. The filter residue obtained from the water leaching process was leached with a mixed solution of sulfuric acid and oxalic acid. The initial concentration of sulfuric acid in the leaching solution was 1.0 mol / L, the initial concentration of oxalic acid was 0.6 mol / L, the solid-liquid ratio was 1:7 (g / mL), the reaction temperature was 70°C, the stirring rate was 300 r / min, and the leaching time was 2 hours. The leaching solution obtained contained nickel, cobalt, and manganese ions, with leaching rates of 99% for all three. After purification and extraction, the leaching solution could be used to produce nickel sulfate, cobalt sulfate, and manganese sulfate.

[0025] Example 5: Waste lithium-ion batteries using lithium nickel cobalt manganese oxide as the cathode material were collected. The cathode material obtained after crushing and dismantling was thoroughly mixed with cobalt carbonate and metallic manganese powder at a mass ratio of 1:2:0.1 to form a mixture. This mixture was then calcined at 500℃ for 1 hour. The calcined product was then leached with deionized water under conditions of high-purity CO2 (purity ≥99.9%). The leaching process was as follows: solid-liquid ratio 1:20 (g / mL), stirring speed 400 r / min, temperature 20℃, CO2 partial pressure at the liquid surface 0.5 MPa, and CO2 aeration rate 0.6 m / s. 3 / (h·m 3 The reaction solution was used for leaching, which lasted for 2.5 hours, achieving a lithium leaching rate of 90%. After leaching, the solution was filtered, and the filtrate was heated to 85°C for pyrolysis for 2 hours. After pyrolysis, the pyrolysis solution was filtered to obtain lithium carbonate. The filter residue obtained from the water leaching process was leached with a mixed solution of sulfuric acid and oxalic acid. The initial concentration of sulfuric acid in the leaching solution was 1.0 mol / L, the initial concentration of oxalic acid was 0.6 mol / L, the solid-liquid ratio was 1:7 (g / mL), the reaction temperature was 70°C, the stirring rate was 300 r / min, and the leaching time was 2 hours. The leaching solution obtained contained nickel, cobalt, and manganese ions, with leaching rates of 99% for all three. After purification and extraction, the leaching solution could be used to produce nickel sulfate, cobalt sulfate, and manganese sulfate.

[0026] Example 6: Waste lithium-ion batteries using lithium nickel cobalt manganese oxide as the cathode material were collected. The cathode material obtained after crushing and dismantling was thoroughly mixed with nickel carbonate and metallic manganese powder at a mass ratio of 1:2:0.1 to form a mixture. This mixture was then calcined at 500℃ for 1 hour. The calcined product was then leached with deionized water under conditions of high-purity CO2 (purity ≥99.9%). The leaching process was as follows: solid-liquid ratio 1:20 (g / mL), stirring speed 400 r / min, temperature 20℃, CO2 partial pressure at the liquid surface 0.5 MPa, and CO2 aeration rate 0.6 m / s. 3 / (h·m 3 The reaction solution was used for leaching, which lasted for 2.5 hours, resulting in a lithium leaching rate of 92%. After leaching, the solution was filtered, and the filtrate was heated to 85°C for pyrolysis for 2 hours. After pyrolysis, the pyrolysis solution was filtered to obtain lithium carbonate. The filter residue obtained from the water leaching process was leached with a mixed solution of sulfuric acid and oxalic acid. The initial concentration of sulfuric acid in the leaching solution was 1.0 mol / L, the initial concentration of oxalic acid was 0.6 mol / L, the solid-liquid ratio was 1:7 (g / mL), the reaction temperature was 70°C, the stirring rate was 300 r / min, and the leaching time was 2 hours. The leaching solution contained nickel, cobalt, and manganese ions, with leaching rates of 99% for all three. After purification and extraction, the leaching solution could be used to produce nickel sulfate, cobalt sulfate, and manganese sulfate.

[0027] Example 7: Waste lithium-ion batteries using lithium nickel cobalt manganese oxide as the cathode material were collected. The cathode material obtained after crushing and dismantling was thoroughly mixed with manganese oxalate and metallic manganese powder at a mass ratio of 1:1.5:0.05 to form a mixture. This mixture was then calcined at 500℃ for 1 hour. The calcined product was then leached with deionized water under conditions of high-purity CO2 (purity ≥99.9%). The leaching process was as follows: solid-liquid ratio 1:20 (g / mL), stirring speed 400 r / min, temperature 20℃, CO2 partial pressure at the liquid surface 0.5 MPa, and CO2 aeration rate 0.6 m / s. 3 / (h·m 3 The reaction solution was used for leaching, which lasted for 2.5 hours, resulting in a lithium leaching rate of 91%. After leaching, the solution was filtered, and the filtrate was heated to 85°C for pyrolysis for 2 hours. After pyrolysis, the pyrolysis solution was filtered to obtain lithium carbonate. The filter residue obtained from the water leaching process was leached with a mixed solution of sulfuric acid and oxalic acid. The initial concentration of sulfuric acid in the leaching solution was 1.0 mol / L, the initial concentration of oxalic acid was 0.6 mol / L, the solid-liquid ratio was 1:7 (g / mL), the reaction temperature was 70°C, the stirring rate was 300 r / min, and the leaching time was 2 hours. The leaching solution contained nickel, cobalt, and manganese ions, with leaching rates of 99% for all three. After purification and extraction, the leaching solution could be used to produce nickel sulfate, cobalt sulfate, and manganese sulfate.

[0028] Example 8: Waste lithium-ion batteries using lithium nickel cobalt manganese oxide as the cathode material were collected. The cathode material obtained after crushing and dismantling was thoroughly mixed with cobalt oxalate and metallic manganese powder at a mass ratio of 1:1.5:0.1 to form a mixture. This mixture was then calcined at 500℃ for 1 hour. The calcined product was then leached with deionized water under conditions of high-purity CO2 (purity ≥99.9%). The leaching process was as follows: solid-liquid ratio 1:20 (g / mL), stirring speed 400 r / min, temperature 20℃, CO2 partial pressure at the liquid surface 0.5 MPa, and CO2 aeration rate 0.6 m / s. 3 / (h·m 3 The reaction solution was used for leaching, which lasted for 2.5 hours, resulting in a lithium leaching rate of 92%. After leaching, the solution was filtered, and the filtrate was heated to 85°C for pyrolysis for 2 hours. After pyrolysis, the pyrolysis solution was filtered to obtain lithium carbonate. The filter residue obtained from the water leaching process was leached with a mixed solution of sulfuric acid and oxalic acid. The initial concentration of sulfuric acid in the leaching solution was 1.0 mol / L, the initial concentration of oxalic acid was 0.6 mol / L, the solid-liquid ratio was 1:7 (g / mL), the reaction temperature was 70°C, the stirring rate was 300 r / min, and the leaching time was 2 hours. The leaching solution contained nickel, cobalt, and manganese ions, with leaching rates of 99% for all three. After purification and extraction, the leaching solution could be used to produce nickel sulfate, cobalt sulfate, and manganese sulfate.

[0029] Example 9: Waste lithium-ion batteries using lithium nickel cobalt manganese oxide as the cathode material were collected. The cathode material obtained after crushing and dismantling was thoroughly mixed with nickel oxalate and metallic manganese powder at a mass ratio of 1:1.5:0.1 to form a mixture. This mixture was then calcined at 500℃ for 1.5 hours. The calcined product was then leached with deionized water under conditions of high-purity CO2 (purity ≥99.9%). The leaching process was as follows: solid-liquid ratio 1:20 (g / mL), stirring speed 400 r / min, temperature 20℃, CO2 partial pressure at the liquid surface 0.5 MPa, and CO2 aeration rate 0.6 m / s. 3 / (h·m 3 The reaction solution was used for leaching, which lasted for 2.5 hours, achieving a lithium leaching rate of 90%. After leaching, the solution was filtered, and the filtrate was heated to 85°C for pyrolysis for 2 hours. After pyrolysis, the pyrolysis solution was filtered to obtain lithium carbonate. The filter residue obtained from the water leaching process was leached with a mixed solution of sulfuric acid and oxalic acid. The initial concentration of sulfuric acid in the leaching solution was 1.0 mol / L, the initial concentration of oxalic acid was 0.6 mol / L, the solid-liquid ratio was 1:7 (g / mL), the reaction temperature was 70°C, the stirring rate was 300 r / min, and the leaching time was 2 hours. The leaching solution obtained contained nickel, cobalt, and manganese ions, with leaching rates of 99% for all three. After purification and extraction, the leaching solution could be used to produce nickel sulfate, cobalt sulfate, and manganese sulfate.

[0030] Example 10: Waste lithium-ion batteries using lithium nickel cobalt manganese oxide as the cathode material were collected. The cathode material obtained after crushing and dismantling was thoroughly mixed with manganese oxalate and metallic nickel powder at a mass ratio of 1:1.5:0.1 to form a mixture. This mixture was then calcined at 500℃ for 1 hour. The calcined product was then leached with deionized water under conditions of high-purity CO2 (purity ≥99.9%). The leaching process was as follows: solid-liquid ratio 1:20 (g / mL), stirring speed 400 r / min, temperature 20℃, CO2 partial pressure at the liquid surface 0.5 MPa, and CO2 aeration rate 0.6 m³ / min. 3 / (h·m 3 The reaction solution was used for leaching, which lasted for 2.5 hours, achieving a lithium leaching rate of 90%. After leaching, the solution was filtered, and the filtrate was heated to 85°C for pyrolysis for 2 hours. After pyrolysis, the pyrolysis solution was filtered to obtain lithium carbonate. The filter residue obtained from the water leaching process was leached with a mixed solution of sulfuric acid and oxalic acid. The initial concentration of sulfuric acid in the leaching solution was 1.0 mol / L, the initial concentration of oxalic acid was 0.6 mol / L, the solid-liquid ratio was 1:7 (g / mL), the reaction temperature was 70°C, the stirring rate was 300 r / min, and the leaching time was 2 hours. The leaching solution obtained contained nickel, cobalt, and manganese ions, with leaching rates of 99% for all three. After purification and extraction, the leaching solution could be used to produce nickel sulfate, cobalt sulfate, and manganese sulfate.

[0031] Example 11: Waste lithium-ion batteries using lithium nickel cobalt manganese oxide as the cathode material were collected. The cathode material obtained after crushing and dismantling was thoroughly mixed with manganese oxalate and metallic cobalt powder at a mass ratio of 1:1.5:0.1 to form a mixture. This mixture was then calcined at 500℃ for 1 hour. The calcined product was then leached with deionized water under conditions of high-purity CO2 (purity ≥99.9%). The leaching process was as follows: solid-liquid ratio 1:20 (g / mL), stirring speed 400 r / min, temperature 20℃, CO2 partial pressure at the liquid surface 0.5 MPa, and CO2 aeration rate 0.6 m / s. 3 / (h·m 3The reaction solution was used for leaching, which lasted for 2.5 hours, resulting in a lithium leaching rate of 91%. After leaching, the solution was filtered, and the filtrate was heated to 85°C for pyrolysis for 2 hours. After pyrolysis, the pyrolysis solution was filtered to obtain lithium carbonate. The filter residue obtained from the water leaching process was leached with a mixed solution of sulfuric acid and oxalic acid. The initial concentration of sulfuric acid in the leaching solution was 1.0 mol / L, the initial concentration of oxalic acid was 0.6 mol / L, the solid-liquid ratio was 1:7 (g / mL), the reaction temperature was 70°C, the stirring rate was 300 r / min, and the leaching time was 2 hours. The leaching solution contained nickel, cobalt, and manganese ions, with leaching rates of 99% for all three. After purification and extraction, the leaching solution could be used to produce nickel sulfate, cobalt sulfate, and manganese sulfate.

[0032] Example 12: Waste lithium-ion batteries using lithium nickel cobalt manganese oxide as the cathode material were collected. The cathode material obtained after crushing and dismantling was thoroughly mixed with manganese carbonate and aluminum powder at a mass ratio of 1:1.5:0.1 to form a mixture. This mixture was then calcined at 500℃ for 1 hour. The calcined product was then leached with deionized water under conditions of high-purity CO2 (purity ≥99.9%). The leaching process was as follows: solid-liquid ratio 1:20 (g / mL), stirring speed 400 r / min, temperature 20℃, CO2 partial pressure at the liquid surface 0.5 MPa, and CO2 aeration rate 0.6 m / s. 3 / (h·m 3 The reaction solution was used for leaching, which lasted for 2.5 hours, resulting in a lithium leaching rate of 92%. After leaching, the solution was filtered, and the filtrate was heated to 85°C for pyrolysis for 2 hours. After pyrolysis, the pyrolysis solution was filtered to obtain lithium carbonate. The filter residue obtained from the water leaching process was leached with a mixed solution of sulfuric acid and oxalic acid. The initial concentration of sulfuric acid in the leaching solution was 1.0 mol / L, the initial concentration of oxalic acid was 0.6 mol / L, the solid-liquid ratio was 1:7 (g / mL), the reaction temperature was 70°C, the stirring rate was 300 r / min, and the leaching time was 2 hours. The leaching solution contained nickel, cobalt, and manganese ions, with leaching rates of 99% for all three. After purification and extraction, the leaching solution could be used to produce nickel sulfate, cobalt sulfate, and manganese sulfate.

[0033] Example 13: Waste lithium-ion batteries using lithium nickel cobalt manganese oxide as the cathode material were collected. The cathode material obtained after crushing and dismantling was thoroughly mixed with sodium bicarbonate and metallic manganese powder at a mass ratio of 1:1.5:0.1 to form a mixture. This mixture was then calcined at 500℃ for 1 hour. The calcined product was then leached with deionized water under conditions of high-purity CO2 (purity ≥99.9%). The leaching process was as follows: solid-liquid ratio 1:20 (g / mL), stirring speed 400 r / min, temperature 20℃, CO2 partial pressure at the liquid surface 0.5 MPa, and CO2 aeration rate 0.6 m / s. 3 / (h·m 3 The reaction solution was used for leaching, which lasted for 2.5 hours, resulting in a lithium leaching rate of 92%. After leaching, the solution was filtered, and the filtrate was heated to 85°C for pyrolysis for 2 hours. After pyrolysis, the pyrolysis solution was filtered to obtain lithium carbonate. The filter residue obtained from the water leaching process was leached with a mixed solution of sulfuric acid and oxalic acid. The initial concentration of sulfuric acid in the leaching solution was 1.0 mol / L, the initial concentration of oxalic acid was 0.6 mol / L, the solid-liquid ratio was 1:7 (g / mL), the reaction temperature was 70°C, the stirring rate was 300 r / min, and the leaching time was 2 hours. The leaching solution contained nickel, cobalt, and manganese ions, with leaching rates of 99% for all three. After purification and extraction, the leaching solution could be used to produce nickel sulfate, cobalt sulfate, and manganese sulfate.

[0034] Example 14: Waste lithium-ion batteries using lithium nickel cobalt manganese oxide as the cathode material were collected. The cathode material obtained after crushing and dismantling was thoroughly mixed with sodium bicarbonate and aluminum powder at a mass ratio of 1:1.5:0.1 to form a mixture. This mixture was then calcined at 500℃ for 1 hour. The calcined product was then leached with deionized water under conditions of high-purity CO2 (purity ≥99.9%). The leaching process was as follows: solid-liquid ratio 1:20 (g / mL), stirring speed 400 r / min, temperature 20℃, CO2 partial pressure at the liquid surface 0.5 MPa, and CO2 aeration rate 0.6 m / s. 3 / (h·m 3 The reaction solution was used for leaching, which lasted for 2.5 hours, achieving a lithium leaching rate of 92%. After leaching, the solution was filtered, and the filtrate was heated to 85°C for pyrolysis for 2 hours. After pyrolysis, the pyrolysis solution was filtered to obtain lithium carbonate. The filter residue obtained from the water leaching process was leached with a mixed solution of sulfuric acid and oxalic acid. The initial concentration of sulfuric acid in the leaching solution was 1.0 mol / L, the initial concentration of oxalic acid was 0.6 mol / L, the solid-liquid ratio was 1:7 (g / mL), the reaction temperature was 70°C, the stirring rate was 300 r / min, and the leaching time was 2 hours. The leaching solution obtained contained nickel, cobalt, and manganese ions, with leaching rates of 99% for all three. After purification and extraction, the leaching solution could be used to produce nickel sulfate, cobalt sulfate, and manganese sulfate.

[0035] Example 15: Waste lithium-ion batteries using lithium nickel cobalt manganese oxide as the cathode material were collected. The cathode material obtained after crushing and dismantling was thoroughly mixed with potassium bicarbonate and metallic manganese powder at a mass ratio of 1:1.5:0.1 to form a mixture. This mixture was then calcined at 500℃ for 1 hour. The calcined product was then leached with deionized water under conditions of high-purity CO2 (purity ≥99.9%). The leaching process was as follows: solid-liquid ratio 1:20 (g / mL), stirring speed 400 r / min, temperature 20℃, CO2 partial pressure at the liquid surface 0.5 MPa, and CO2 aeration rate 0.6 m / s. 3 / (h·m 3 The reaction solution was used for leaching, which lasted for 2.5 hours, achieving a lithium leaching rate of 90%. After leaching, the solution was filtered, and the filtrate was heated to 85°C for pyrolysis for 2 hours. After pyrolysis, the pyrolysis solution was filtered to obtain lithium carbonate. The filter residue obtained from the water leaching process was leached with a mixed solution of sulfuric acid and oxalic acid. The initial concentration of sulfuric acid in the leaching solution was 1.0 mol / L, the initial concentration of oxalic acid was 0.6 mol / L, the solid-liquid ratio was 1:7 (g / mL), the reaction temperature was 70°C, the stirring rate was 300 r / min, and the leaching time was 2 hours. The leaching solution obtained contained nickel, cobalt, and manganese ions, with leaching rates of 99% for all three. After purification and extraction, the leaching solution could be used to produce nickel sulfate, cobalt sulfate, and manganese sulfate.

Claims

1. A method for extracting metals from the cathode material of spent lithium-ion batteries, characterized in that, Includes the following steps: (1) Obtain cathode materials from waste lithium-ion batteries; (2) The waste lithium-ion battery cathode material obtained in step (1) is thoroughly mixed with the additives at a mass ratio of 1:0.05-4.5 to obtain a mixture; (3) The mixture obtained in step (2) is calcined at 200-600℃ for 0.5-3.5h to obtain the calcined product; (4) The calcined product obtained in step (3) is leached with deionized water at a solid-liquid ratio of 1:10-25. During the leaching process, the mixture is stirred, the temperature is controlled, and a solution with a purity ≥99.9% is introduced into the water. The process lasts 1-3 hours. (5) After the process described in step (4) is completed, filtration is performed to obtain filtrate and filter residue; The filtrate is heated to 80-100℃ for pyrolysis for 1-3 hours. After pyrolysis, the pyrolysis solution is subjected to solid-liquid separation to obtain lithium carbonate product. The filter residue is leached with a mixed solution of sulfuric acid and oxalic acid for 0.5-3 hours. After leaching, a leachate containing nickel, cobalt and manganese ions is obtained. The leachate is then purified and extracted to produce nickel, cobalt and manganese products.

2. The method as described in claim 1, characterized in that, In step (1), the sources of the waste lithium-ion battery cathode material include: cathode waste obtained after dismantling, crushing, sorting, screening and flotation separation of collected waste lithium-ion batteries, cathode waste obtained after crushing, sorting, screening and flotation separation of cathode scraps generated during the lithium-ion battery production process, cathode waste generated during the research and production of lithium-ion battery cathode materials, or a mixture of the above three cathode wastes in any combination.

3. The method as described in claim 1, characterized in that, In step (1), the waste lithium-ion battery cathode material includes a mixture of one or more substances from lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, nickel-cobalt binary, nickel-manganese binary, cobalt-manganese binary, nickel-cobalt-manganese ternary, nickel-cobalt-aluminum ternary materials, and lithium-rich manganese-based layered oxide cathode materials.

4. The method as described in claim 1, characterized in that, In step (2), the additive is one or more of the following substances: manganese carbonate, cobalt carbonate, nickel carbonate, manganese oxalate, cobalt oxalate, nickel oxalate, oxalic acid, sodium oxalate, potassium oxalate, ammonium oxalate, basic manganese carbonate, basic cobalt carbonate, basic nickel carbonate, sodium bicarbonate, potassium bicarbonate, ammonium bicarbonate, and ammonium carbonate.

5. The method as described in claim 1, characterized in that, In step (2), the additive is a mixture formed by fully mixing one or more of the following substances: manganese carbonate, cobalt carbonate, nickel carbonate, manganese oxalate, cobalt oxalate, nickel oxalate, oxalic acid, sodium oxalate, potassium oxalate, ammonium oxalate, basic manganese carbonate, basic cobalt carbonate, basic nickel carbonate, sodium bicarbonate, potassium bicarbonate, ammonium bicarbonate, and ammonium carbonate with one or more of the following substances: metallic manganese powder, metallic nickel powder, metallic cobalt powder, and metallic aluminum powder.

6. The method as described in claim 1, characterized in that, In step (4), the stirring rate is 300-500 r / min, the temperature is 10-30℃, and the liquid surface... Partial pressure 0.2-1.2 MPa ventilation rate .

7. The method as described in claim 1, characterized in that, In step (5), the initial concentration of sulfuric acid in the leachate is 1.0-1.5 mol / L, the initial concentration of oxalic acid is 0.3-0.6 mol / L, the solid-liquid ratio is 1:6-10, the reaction temperature is 50-80℃, and the stirring rate is 300-600 r / min.

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