Process for the recovery of nickel, cobalt, manganese and lithium

Abstract

The application provides a recovery method of nickel, cobalt, manganese and lithium. The recovery method comprises the following steps: step S1, sequentially disassembling, crushing, heat treating and removing magnetism of lithium battery recovery material to obtain black powder; step S2, decomposing the black powder by using acidophilic bacteria solution to remove copper elements and aluminum elements, and obtaining a decomposed product; step S3, acid leaching the decomposed product to obtain a leaching solution; step S4, fractionally extracting the leaching solution to obtain a raffinate, a manganese salt solution, a cobalt salt solution and a nickel salt solution; step S5, evaporating and crystallizing the raffinate to obtain a lithium salt solution; and step S6, independently co-precipitating the manganese salt solution, the cobalt salt solution, the nickel salt solution and the lithium salt solution to obtain manganese salt solid, cobalt salt solid, nickel salt solid and lithium salt solid. The recovery method provided by the application is helpful to improve the purity and yield of the recovery of nickel, cobalt, manganese and lithium.

Description

Technical Field

[0001] This application relates to the field of metal recycling technology, and more specifically, to a method for recycling nickel, cobalt, manganese and lithium. Background Technology

[0002] With technological advancements and strong government support, consumer electronics are constantly being upgraded, and new energy vehicles and energy storage batteries are becoming increasingly widespread, leading to a rapid increase in the demand for lithium-ion batteries. Against this backdrop, lithium-ion battery manufacturers are continuously expanding their production capacity. As lithium batteries gradually enter their end-of-life stage, the demand for lithium battery recycling is growing rapidly. Given the current situation of continuously rising prices of upstream lithium battery materials and the increasing scarcity of upstream metal resources, the economic benefits of lithium battery material recycling will become increasingly prominent. The metal elements in lithium batteries have economic value and can be recycled, becoming one of the important sources of raw materials for lithium-ion battery production. Lithium battery recycling can effectively reduce battery costs.

[0003] Traditional methods for preparing recycled materials suffer from low recycling efficiency and significant environmental pollution, making it difficult to meet current recycling requirements. The recovery of metal elements from lithium-ion batteries is limited by the diverse range of recycling sources, resource scarcity, and the complexity of recycling and purification processes, resulting in recycled materials that cannot meet market demand. Furthermore, the choice of recycling process significantly impacts the purity of the recycled materials and environmental pollution. Therefore, selecting suitable recycling sources and processes is crucial for improving the purity of recycled materials; however, current traditional recycling processes have not yet achieved the desired results. Summary of the Invention

[0004] The main objective of this application is to provide a method for recovering nickel, cobalt, manganese and lithium, in order to solve the problem of low recovery rates in the prior art for recovering nickel, cobalt, manganese and lithium.

[0005] To achieve the above objectives, according to one aspect of this application, a method for recovering nickel, cobalt, manganese, and lithium is provided. This method includes the following steps: Step S1, sequentially dismantling, crushing, heat-treating, and demagnetizing the lithium battery recycled material to obtain black powder; Step S2, decomposing the black powder using acidophilic bacteria solution to remove copper and aluminum elements, obtaining decomposition products; Step S3, acid leaching the decomposition products to obtain a leachate; Step S4, fractionally extracting the leachate to obtain raffinate, a manganese salt solution, a cobalt salt solution, and a nickel salt solution; Step S5, evaporating and crystallizing the raffinate to obtain a lithium salt solution; Step S6, independently co-precipitating the manganese salt solution, cobalt salt solution, nickel salt solution, and lithium salt solution to obtain solid manganese salt, solid cobalt salt, solid nickel salt, and solid lithium salt.

[0006] Furthermore, in step S2 above, the OD600 of the acidophilic bacteria solution is 0.6 to 1; and / or, the mass ratio of black powder to the volume of the acidophilic bacteria solution is 1:10 to 20.

[0007] Further, in step S2 above, the acidophilic bacteria solution is mixed with black powder to obtain a mixed solution; the pH value of the mixed solution is adjusted to 1-3 and then decomposed; further, the decomposition time is 3-7 days; and / or, the decomposition temperature is 30-50℃.

[0008] Furthermore, the aforementioned acidophilic bacterial solution is an A. monosulfide oxidizing bacterial solution, an Acb. disulfide oxidizing bacterial solution, or a mixed bacterial solution of A. monosulfide oxidizing bacterial solution and Acb. disulfide oxidizing bacterial solution; furthermore, the mixed bacterial solution is composed of an A. monosulfide oxidizing bacterial solution with an OD600 of 0.6 to 1 and an Acb. disulfide oxidizing bacterial solution with an OD600 of 0.6 to 1, and the volume ratio of the A. monosulfide oxidizing bacterial solution to the Acb. disulfide oxidizing bacterial solution is 1:0.5 to 2.

[0009] Further, step S4 includes: step S41, mixing the leachate with the first extractant to obtain a first mixture, adjusting the pH of the first mixture to 2-3, and then performing a first extraction and a first back-extraction sequentially to obtain a first raffinate and a manganese salt solution; step S42, mixing the first raffinate with the second extractant to obtain a second mixture, adjusting the pH of the second mixture to 4-5, and then performing a second extraction and a second back-extraction sequentially to obtain a second raffinate and a cobalt salt solution; step S43, mixing the second raffinate with the third extractant to obtain a third mixture, adjusting the pH of the third mixture to 7-8, and then performing a third extraction and a third back-extraction sequentially to obtain a raffinate and a nickel salt solution.

[0010] Further, the volume ratio of the leachate to the first extractant is 1:0.1 to 1; and / or, the volume ratio of the first raffinate to the second extractant is 1:0.1 to 1; and / or, the volume ratio of the second raffinate to the third extractant is 1:0.1 to 1; further, the concentrations of the first, second, and third extractants are each independently 0.2 to 1 mol / L; and / or, the temperatures of the first, second, and third extractions are each independently 25 to 50 °C; further, the first extractant is P204 extractant and / or A308 extractant; and / or, the second extractant is P507 extractant and / or A308 extractant; and / or, the third extractant is C272 extractant and / or A308 extractant.

[0011] Furthermore, in step S1 above, the heat treatment temperature is 300–800°C; and / or the heat treatment time is 1–8 h; and / or the median particle size of the black powder is 5–30 μm.

[0012] Further, in step S3 above, acid is used to leach the decomposed product; further, the mass ratio of acid to decomposed product is 1:1 to 10; and / or, the leaching temperature is 20 to 50°C; and / or, the leaching time is 1 to 6 hours; further, the acid is sulfuric acid and / or hydrochloric acid.

[0013] Furthermore, in step S5 above, the evaporation and crystallization temperature is 80–150°C; and / or the evaporation and crystallization time is 1–6 hours.

[0014] Furthermore, the temperature of the coprecipitation is 20–30°C; and / or the coprecipitation time is 1–6 h; furthermore, the precipitant used in the coprecipitation is selected from any one or more of NH4HCO3, NaHCO3, Na2CO3 and NaOH.

[0015] Applying the technical solution of this application, in step S1, the lithium battery recycled material is disassembled and crushed sequentially, which helps to separate the materials containing recycled elements. Organic components are removed from the material through heat treatment, and magnetic impurities such as Fe are removed through demagnetization. In step S2, acidophilic bacteria solution is used to decompose the black powder, which helps to remove copper and aluminum elements from the black powder, thereby improving the purity and yield of the recycled metals. In step S3, the decomposed material is acid-leached to dissolve manganese, cobalt, nickel, and lithium, obtaining a leachate. In step S4, manganese, cobalt, nickel, and lithium in the leachate are effectively separated through fractional extraction. This application effectively recovers nickel, cobalt, manganese, and lithium from lithium battery recycled material by employing a composite recycling process combining physical recycling, biological recycling, and wet recycling. In particular, the use of acidophilic bacteria for biological recycling makes the purification of metal elements more efficient. Simultaneously, fractional extraction enables selective separation of different metals. Therefore, the recycling method of this application helps to improve the purity and yield of nickel, cobalt, manganese and lithium recovery. At the same time, the recycling method of this application has good process stability, low environmental pollution and can simplify the production process and reduce raw material and production costs as needed. Detailed Implementation

[0016] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present application will now be described in detail with reference to the embodiments.

[0017] As analyzed in the background section of this application, the prior art has the problem of low recovery rates in the recycling of nickel, cobalt, manganese and lithium. In order to solve this problem, this application provides a method for recycling nickel, cobalt, manganese and lithium.

[0018] In a typical embodiment of this application, a method for recovering nickel, cobalt, manganese, and lithium is provided. The method includes the following steps: Step S1, dismantling, crushing, heat-treating, and demagnetizing the lithium battery recycled material sequentially to obtain black powder; Step S2, decomposing the black powder with acidophilic bacteria solution to remove copper and aluminum elements, obtaining decomposition products; Step S3, acid leaching the decomposition products to obtain a leachate; Step S4, fractionating and extracting the leachate to obtain raffinate, manganese salt solution, cobalt salt solution, and nickel salt solution; Step S5, evaporating and crystallizing the raffinate to obtain a lithium salt solution; Step S6, independently co-precipitating the manganese salt solution, cobalt salt solution, nickel salt solution, and lithium salt solution to obtain solid manganese salt, solid cobalt salt, solid nickel salt, and solid lithium salt.

[0019] In step S1, the lithium battery recycled material is disassembled and crushed sequentially, which helps to separate materials containing recycled elements. Organic components are removed through heat treatment, and magnetic impurities such as Fe are removed through demagnetization. In step S2, acidophilic bacteria solution is used to decompose the black powder, which helps to remove copper and aluminum elements, thereby improving the purity and yield of the recycled metals. In step S3, the decomposed material is acid-leached to dissolve manganese, cobalt, nickel, and lithium, obtaining a leachate. In step S4, manganese, cobalt, nickel, and lithium in the leachate are effectively separated through fractional extraction. This application effectively recovers nickel, cobalt, manganese, and lithium from lithium battery recycled material by employing a composite recycling process combining physical recycling, biological recycling, and wet recycling. In particular, the use of acidophilic bacteria for biological recycling makes the purification of metal elements more efficient. Simultaneously, fractional extraction enables selective separation of different metals. Therefore, the recycling method of this application helps to improve the purity and yield of nickel, cobalt, manganese and lithium recovery. At the same time, the recycling method of this application has good process stability, low environmental pollution and can simplify the production process and reduce raw material and production costs as needed.

[0020] The aforementioned lithium battery recycled materials come from lithium battery cathode precursor recycled materials, lithium battery cathode material recycled materials, lithium battery cathode slurry recycled materials, lithium battery electrode recycled materials, and waste lithium battery recycled materials.

[0021] In one embodiment of this application, in step S2 above, the OD600 of the acidophilic bacteria solution is 0.6 to 1; and / or, the mass ratio of black powder to the volume of the acidophilic bacteria solution is 1:10 to 20.

[0022] Higher bacterial concentrations can increase the dissolution rates of copper and aluminum because more microbial cells can participate in the metal redox process, thereby increasing the release of copper and aluminum. However, excessively high bacterial concentrations may lead to insufficient oxygen supply in the bioreactor, affecting microbial growth and activity, and potentially increasing treatment costs. Therefore, controlling the concentration of the acidophilic bacterial solution within the aforementioned range helps improve the removal efficiency of copper and aluminum. Controlling the mass ratio of black powder to the volume of acidophilic bacterial solution within the aforementioned range helps ensure sufficient contact between the acidophilic bacteria and the black powder, thereby further improving the removal rate of copper and aluminum.

[0023] The OD600 of the above-mentioned acidophilic bacteria solution can be 0.6, 0.7, 0.8, 0.9, or 1. The mass ratio of black powder to the volume of acidophilic bacteria solution can be 1:10, 1:11, 1:12, 1:13, 1:14, 1:15, 1:16, 1:17, 1:18, 1:19, or 1:20.

[0024] In one embodiment of this application, in step S2 above, the acidophilic bacteria solution is mixed with black powder to obtain a mixture; the pH value of the mixture is adjusted to 1-3 and then decomposed; in one embodiment of this application, the decomposition time is 3-7 days; and / or, the decomposition temperature is 30-50°C.

[0025] Acidophilic bacteria exhibit higher activity in acidic environments. Controlling the pH of the mixed solution within the aforementioned range helps to control the selective dissolution of copper and aluminum by acidophilic bacteria, thereby improving the recovery rate of the recovered metals. Controlling the decomposition time and temperature within the aforementioned range helps to enhance the redox ability of acidophilic bacteria for copper and aluminum, thus further improving the purity of the recovered metals.

[0026] The decomposition time can be 3, 4, 5, 6, or 7 days. The decomposition temperature can be 30℃, 35℃, 40℃, 45℃, or 50℃.

[0027] In one embodiment of this application, the pH adjuster for adjusting the above mixture is an acid; in another embodiment of this application, the acid is hydrochloric acid and / or sulfuric acid.

[0028] In one embodiment of this application, the acidophilic bacterial solution is an A. monosulfide oxidizing bacterial solution, an Acb. disulfide oxidizing bacterial solution, or a mixed bacterial solution of A. monosulfide oxidizing bacterial solution and Acb. disulfide oxidizing bacterial solution; in one embodiment of this application, the mixed bacterial solution is composed of an A. monosulfide oxidizing bacterial solution with an OD600 of 0.6 to 1 and an Acb. disulfide oxidizing bacterial solution with an OD600 of 0.6 to 1, and the volume ratio of the A. monosulfide oxidizing bacterial solution to the Acb. disulfide oxidizing bacterial solution is 1:0.5 to 2.

[0029] The combined action of A. monosulfide oxidizing bacteria and Acb. disulfide oxidizing bacteria on refined black powder helps to enhance the synergistic effect between the two, biocatalytically oxidizing the copper and aluminum elements in the black powder. The A. monosulfide oxidizing bacteria and Acb. disulfide oxidizing bacteria combine with the catalytically oxidized copper and aluminum ions to form organic covalent compounds, which helps to further improve the removal efficiency of copper and aluminum, thereby helping to improve the purity and efficiency of the recovered material.

[0030] The volume ratio of the above-mentioned A. monosulfide oxidizing bacterial solution and Acb. disulfide oxidizing bacterial solution can be 1:0.5, 1:1, 1:1.5 or 1:2.

[0031] In one embodiment of this application, acidophilic bacteria were cultured in FeS medium for 21 days at 30°C and 150 rpm to obtain an acidophilic bacterial solution. In another embodiment of this application, the acidophilic bacteria were either *A. monosulfide oxidizer* or *Acb. disulfide oxidizer*. The *A. monosulfide oxidizer* was purchased from Shanghai Baozang Biotechnology Center (model SHMCCD71747), and the *Acb. disulfide oxidizer* was purchased from Wuhan Ruichen Standard Materials Technology Co., Ltd. (model SMHCC S71747).

[0032] In one embodiment of this application, step S4 includes: step S41, mixing the leachate with a first extractant to obtain a first mixture, adjusting the pH of the first mixture to 2-3, and then performing a first extraction and a first back-extraction sequentially to obtain a first raffinate and a manganese salt solution; step S42, mixing the first raffinate with a second extractant to obtain a second mixture, adjusting the pH of the second mixture to 4-5, and then performing a second extraction and a second back-extraction sequentially to obtain a second raffinate and a cobalt salt solution; step S43, mixing the second raffinate with a third extractant to obtain a third mixture, adjusting the pH of the third mixture to 7-8, and then performing a third extraction and a third back-extraction sequentially to obtain a raffinate and a nickel salt solution.

[0033] By adjusting the pH value at different stages, the solubility of metal ions and the selectivity of the extractant can be controlled. At a pH of 2–3, manganese salts can be effectively extracted, while at a higher pH of 4–5, cobalt salts are extracted, and at an even higher pH of 7–8, nickel salts are suitable for extraction. This stepwise pH adjustment strategy helps to achieve the sequential separation of manganese, cobalt, and nickel metals, thereby improving the purity and efficiency of metal recovery.

[0034] Including but not limited to, the stripping agent used in the first stripping, the stripping agent used in the second stripping, and the stripping agent used in the third stripping are all sulfuric acid.

[0035] In one embodiment of this application, the pH adjuster used in the extraction process is 1-2 mol / L NaOH or KOH.

[0036] In one embodiment of this application, the volume ratio of the leachate to the first extractant is 1:0.1 to 1; and / or, the volume ratio of the first raffinate to the second extractant is 1:0.1 to 1; and / or, the volume ratio of the second raffinate to the third extractant is 1:0.1 to 1; in one embodiment of this application, the concentrations of the first extractant, the second extractant, and the third extractant are each independently 0.2 to 1 mol / L; and / or, the temperatures of the first extraction, the second extraction, and the third extraction are each independently 25 to 50°C; in one embodiment of this application, the first extractant is P204 extractant and / or A308 extractant; and / or, the second extractant is P507 extractant and / or A308 extractant; and / or, the third extractant is C272 extractant and / or A308 extractant.

[0037] Controlling the volume ratios of the leachate to the first extractant, the first raffinate to the second extractant, and the second raffinate to the third extractant within the aforementioned ranges helps to improve the metal extraction rate. The extractant concentration affects the partition coefficient of metal ions between the extractant and the aqueous phase; controlling the concentrations of the first, second, and third extractants within the aforementioned ranges helps to improve the selectivity of metal separation, thereby contributing to increased metal recovery yield and purity. Controlling the temperatures of the first, second, and third extractions within the aforementioned ranges helps to improve extraction efficiency. Controlling the types of the first, second, and third extractants within the aforementioned ranges helps to further improve the selectivity of metal separation.

[0038] In one embodiment of this application, in step S1 above, the heat treatment temperature is 300-800°C; and / or the heat treatment time is 1-8 hours; and / or the median particle size of the black powder is 5-30 μm.

[0039] Lower heat treatment temperatures may be insufficient to completely decompose organic matter, leading to organic residues that could interfere with metal recovery in subsequent processing. Excessively high temperatures may cause metal oxidation loss, especially lithium, resulting in a decreased recovery rate. Controlling the heat treatment temperature within the aforementioned range helps reduce metal loss while removing organic matter, thus improving metal recovery efficiency and purity. Controlling the heat treatment time within the aforementioned range helps reduce energy consumption while removing organic matter. Smaller black powder particle size increases the contact area between the metal and the treatment reagent, facilitating metal dissolution and impurity separation. However, excessively small particle size may cause dust problems during processing, increasing recovery costs, and excessively fine powder may be more difficult to separate in subsequent physical sorting. Controlling the median black powder particle size within the aforementioned range helps balance metal recovery efficiency and operational convenience, reducing energy consumption and lowering production costs.

[0040] In one embodiment of this application, in step S3 above, acid is used to leach the decomposed product; in one embodiment of this application, the mass ratio of acid to decomposed product is 1:1 to 10; and / or, the leaching temperature is 20 to 50°C; and / or, the leaching time is 1 to 6 hours; in one embodiment of this application, the acid is sulfuric acid and / or hydrochloric acid.

[0041] Acid leaching removes manganese, cobalt, nickel, and lithium from the decomposed products. Controlling the mass ratio of acid to decomposed products within the aforementioned range helps improve metal leaching efficiency. Lower acid leaching temperatures reduce energy consumption but may prolong the metal dissolution time. Higher acid leaching temperatures accelerate metal dissolution, but excessively high temperatures may cause rapid acid volatilization and metal oxidation, affecting the purity and efficiency of metal recovery. Controlling the acid leaching temperature within the aforementioned range helps control energy consumption and reduce metal loss while improving metal dissolution efficiency. Controlling the acid leaching time within the aforementioned range also helps improve metal dissolution efficiency.

[0042] In one embodiment of this application, in step S5 above, the evaporation and crystallization temperature is 80-150°C; and / or the evaporation and crystallization time is 1-6 hours.

[0043] Enriching lithium salt solutions through evaporation crystallization, and controlling the evaporation crystallization temperature and time within the aforementioned range, helps to further improve the purity and yield of metallic lithium.

[0044] In one embodiment of this application, the temperature of the co-precipitation is 20-30°C; and / or the co-precipitation time is 1-6 hours; in one embodiment of this application, the precipitant used in the co-precipitation is selected from any one or more of NH4HCO3, NaHCO3, Na2CO3 and NaOH.

[0045] Nickel, cobalt, manganese, and lithium are separated from solution through co-precipitation to form a precipitate, which can be used as a raw material for preparing cathode materials. Controlling the temperature and time of co-precipitation within the aforementioned range helps to improve the efficiency of co-precipitation.

[0046] The beneficial effects of this application will be further illustrated below with reference to the embodiments.

[0047] Example 1

[0048] S1: 1000g of ternary lithium batteries of model 18650 are used as raw materials. After dismantling, discharging, crushing and eddy current separation, coarse black powder is obtained.

[0049] S2: The crude black powder is heat-treated at 500℃ for 3 hours to remove organic components and obtain the heat-treated product.

[0050] S3: The heat-treated product is demagnetized and then subjected to secondary crushing and fine grinding to obtain black powder with a median particle size of 20μm.

[0051] S4: The *A. monosulfide oxidizing bacteria* (model SMHCC D71747) from Shanghai Baozang Biotechnology Center was cultured in FeS medium for 21 days at 30℃ and 150 rpm to obtain an *A. monosulfide oxidizing bacteria solution with an OD600 of 0.6. Black powder was mixed with the *A. monosulfide oxidizing bacteria solution, and an appropriate amount of sulfuric acid was added to adjust the pH to 1 for decomposition. The mass ratio of black powder to the volume of the *A. monosulfide oxidizing bacteria solution was 1:10. The decomposition time was 3 days, and the decomposition temperature was 30℃, yielding the decomposition products.

[0052] S5: The decomposition products are acid-leached with 98% concentrated sulfuric acid. The mass ratio of 98% concentrated sulfuric acid to decomposition products is 1:1. The acid leaching temperature is 20℃ and the acid leaching time is 6h to obtain the leachate.

[0053] S6: Add P204 extractant to the leachate, adjust the pH to 2 with 1 mol / L NaOH, the concentration of P204 extractant is 1 mol / L, the extraction temperature is 25℃, and the volume ratio of leachate to P204 extractant is 1:0.1. Then, back-extract and separate using sulfuric acid as a back-extraction agent to obtain the first raffinate and MnSO4 solution; add P507 extractant to the first raffinate, adjust the pH to 4 with 1 mol / L NaOH, the concentration of P507 extractant is 1 mol / L, and the extraction temperature is... At 25℃, the volume ratio of the first raffinate to P507 extractant was 1:0.1. Then, sulfuric acid was used as a back-extraction agent for back-extraction and separation to obtain the second raffinate and CoSO4 solution. Next, C272 extractant was added to the second raffinate, and the pH was adjusted to 7 with 1 mol / L NaOH. The concentration of C272 extractant was 1 mol / L, and the extraction temperature was 25℃. The volume ratio of the second raffinate to C272 extractant was 1:0.1. Sulfuric acid was then used as a back-extraction agent for back-extraction and separation to obtain the raffinate and NiSO4 solution.

[0054] S7: Evaporate and crystallize the raffinate at a temperature of 80℃ for 6 hours to obtain a Li2SO4 solution.

[0055] S8: The obtained MnSO4 solution, CoSO4 solution, NiSO4 solution and Li2SO4 solution were each subjected to coprecipitation reaction independently. The precipitant was NH4HCO3. The coprecipitation temperature was 20℃ and the coprecipitation time was 6h. The obtained precipitates were filtered, washed and dried to obtain manganese carbonate, cobalt carbonate, nickel carbonate and lithium carbonate.

[0056] Example 2

[0057] The difference from Example 1 is that the OD600 of A. monosulfide oxidizing bacterial solution is 1, and the mass ratio of black powder to the volume of A. monosulfide oxidizing bacterial solution is 1:20, ultimately yielding manganese carbonate, cobalt carbonate, nickel carbonate and lithium carbonate.

[0058] Example 3

[0059] The difference from Example 1 is that the OD600 of A. monosulfide oxidizing bacterial solution is 2, and the mass ratio of black powder to the volume of A. monosulfide oxidizing bacterial solution is 1:40, ultimately yielding manganese carbonate, cobalt carbonate, nickel carbonate, and lithium carbonate.

[0060] Example 4

[0061] The difference from Example 1 is that after mixing the black powder with A. monosulfide oxidizing bacteria solution, an appropriate amount of sulfuric acid was added to adjust the pH to 3 for decomposition. The decomposition time was 7 days and the decomposition temperature was 50°C, finally yielding manganese carbonate, cobalt carbonate, nickel carbonate and lithium carbonate.

[0062] Example 5

[0063] The difference from Example 1 is that after mixing the black powder with A. monosulfide oxidizing bacteria solution, an appropriate amount of sulfuric acid was added to adjust the pH to 4 for decomposition. The decomposition time was 1 day and the decomposition temperature was 20°C, finally yielding manganese carbonate, cobalt carbonate, nickel carbonate and lithium carbonate.

[0064] Example 6

[0065] The difference from Example 1 is that *A. monosulfide oxidizing bacteria* (model SMHCC D71747) from Shanghai Baozang Biotechnology Center was cultured in FeS medium for 21 days at 30°C and 150 rpm to obtain an *A. monosulfide oxidizing bacteria solution with an OD600 of 0.6. *Acb. disulfide oxidizing bacteria* (model SMHCC S71747) from Wuhan Ruichen Standard Materials Technology Co., Ltd. was also cultured in FeS medium for 21 days at 30°C and 150 rpm to obtain an *Acb. disulfide oxidizing bacteria solution with an OD600 of 0.6. The *A. monosulfide oxidizing bacteria solution and the *Acb. disulfide oxidizing bacteria solution were mixed at a volume ratio of 1:0.5 to obtain a mixed bacterial solution. This mixed bacterial solution was used to decompose black powder, ultimately yielding manganese carbonate, cobalt carbonate, nickel carbonate, and lithium carbonate.

[0066] Example 7

[0067] The difference from Example 1 is that *A. monosulfide oxidizing bacteria* (model SMHCC D71747) from Shanghai Baozang Biotechnology Center was cultured in FeS medium for 21 days at 30°C and 150 rpm to obtain an *A. monosulfide oxidizing bacteria solution with an OD600 of 0.6. *Acb. disulfide oxidizing bacteria* (model SMHCC S71747) from Wuhan Ruichen Standard Materials Technology Co., Ltd. was also cultured in FeS medium for 21 days at 30°C and 150 rpm to obtain an *Acb. disulfide oxidizing bacteria solution with an OD600 of 0.6. The *A. monosulfide oxidizing bacteria solution and the *Acb. disulfide oxidizing bacteria solution were mixed at a volume ratio of 1:2 to obtain a mixed bacterial solution. This mixed bacterial solution was used to decompose black powder, ultimately yielding manganese carbonate, cobalt carbonate, nickel carbonate, and lithium carbonate.

[0068] Example 8

[0069] The difference from Example 1 is that P204 extractant was added to the leachate, the pH was adjusted to 3 with 1 mol / L NaOH, the concentration of P204 extractant was 1 mol / L, the extraction temperature was 25°C, and the volume ratio of leachate to P204 extractant was 1:0.1. Then, sulfuric acid was used for back-extraction and separation to obtain a first raffinate and a MnSO4 solution. P507 extractant was added to the first raffinate, the pH was adjusted to 5 with 1 mol / L NaOH, the concentration of P507 extractant was 1 mol / L, and the extraction temperature was 25°C. The volume ratio of the raffinate to the P507 extractant was 1:0.1. Then, sulfuric acid was used as a back-extraction agent for back-extraction and separation to obtain a second raffinate and a CoSO4 solution. Next, C272 extractant was added to the second raffinate, and the pH was adjusted to 8 with 1 mol / L NaOH. The concentration of C272 extractant was 1 mol / L, and the extraction temperature was 25℃. The volume ratio of the second raffinate to the C272 extractant was 1:0.1. Sulfuric acid was then used as a back-extraction agent for back-extraction and separation to obtain a raffinate and a NiSO4 solution, ultimately yielding manganese carbonate, cobalt carbonate, nickel carbonate, and lithium carbonate.

[0070] Example 9

[0071] The difference from Example 1 is that P204 extractant was added to the leachate, the pH was adjusted to 4 with 1 mol / L NaOH, the concentration of P204 extractant was 1 mol / L, the extraction temperature was 25°C, and the volume ratio of leachate to P204 extractant was 1:0.1. Then, sulfuric acid was used for back-extraction and separation to obtain a first raffinate and a MnSO4 solution. P507 extractant was added to the first raffinate, the pH was adjusted to 6 with 1 mol / L NaOH, the concentration of P507 extractant was 1 mol / L, and the extraction temperature was 25°C. The volume ratio of raffinate to P507 extractant was 1:0.1. Then, sulfuric acid was used as a back-extraction agent for back-extraction and separation to obtain a second raffinate and a CoSO4 solution. Next, C272 extractant was added to the second raffinate, and the pH was adjusted to 9 with 1 mol / L NaOH. The concentration of C272 extractant was 1 mol / L, and the extraction temperature was 25℃. The volume ratio of the second raffinate to C272 extractant was 1:0.1. Sulfuric acid was then used as a back-extraction agent for back-extraction and separation to obtain a raffinate and a NiSO4 solution, ultimately yielding manganese carbonate, cobalt carbonate, nickel carbonate, and lithium carbonate.

[0072] Example 10

[0073] The difference from Example 1 is that P204 extractant was added to the leachate, the pH was adjusted to 2 with 1 mol / L NaOH, the concentration of P204 extractant was 1 mol / L, the extraction temperature was 50°C, and the volume ratio of leachate to P204 extractant was 1:1. Then, sulfuric acid was used for back-extraction and separation to obtain the first raffinate and MnSO4 solution. P507 extractant was added to the first raffinate, the pH was adjusted to 4 with 1 mol / L NaOH, the concentration of P507 extractant was 1 mol / L, and the extraction temperature was 50°C. The volume ratio of the first raffinate to P507 extractant is 1:1. Then, sulfuric acid is used as a back-extraction agent for back-extraction and separation to obtain a second raffinate and a CoSO4 solution. Next, C272 extractant is added to the second raffinate, and the pH is adjusted to 7 with 1 mol / L NaOH. The concentration of C272 extractant is 1 mol / L, and the extraction temperature is 50℃. The volume ratio of the second raffinate to C272 extractant is 1:1. Sulfuric acid is then used as a back-extraction agent for back-extraction and separation to obtain a raffinate and a NiSO4 solution, ultimately yielding manganese carbonate, cobalt carbonate, nickel carbonate, and lithium carbonate.

[0074] Example 11

[0075] The difference from Example 1 is that P204 extractant was added to the leachate, the pH was adjusted to 2 with 1 mol / L NaOH, the concentration of P204 extractant was 1 mol / L, the extraction temperature was 55°C, and the volume ratio of leachate to P204 extractant was 1:2. Then, sulfuric acid was used for back-extraction and separation to obtain the first raffinate and MnSO4 solution. P507 extractant was added to the first raffinate, the pH was adjusted to 4 with 1 mol / L NaOH, the concentration of P507 extractant was 1 mol / L, and the extraction temperature was 55°C. The volume ratio of the first raffinate to P507 extractant is 1:2. Then, sulfuric acid is used as a back-extraction agent for back-extraction and separation to obtain a second raffinate and a CoSO4 solution. Next, C272 extractant is added to the second raffinate, and the pH is adjusted to 7 with 1 mol / L NaOH. The concentration of C272 extractant is 1 mol / L, and the extraction temperature is 55℃. The volume ratio of the second raffinate to C272 extractant is 1:2. Sulfuric acid is then used as a back-extraction agent for back-extraction and separation to obtain a raffinate and a NiSO4 solution, ultimately yielding manganese carbonate, cobalt carbonate, nickel carbonate, and lithium carbonate.

[0076] Example 12

[0077] The difference from Example 1 is that the heat treatment temperature is 300°C, the heat treatment time is 8 hours, the median particle size of the black powder is 5 μm, and finally manganese carbonate, cobalt carbonate, nickel carbonate and lithium carbonate are obtained.

[0078] Example 13

[0079] The difference from Example 1 is that the heat treatment temperature is 800°C, the heat treatment time is 1 hour, the median particle size of the black powder is 30 μm, and finally manganese carbonate, cobalt carbonate, nickel carbonate and lithium carbonate are obtained.

[0080] Example 14

[0081] The difference from Example 1 is that the heat treatment temperature is 900°C, the heat treatment time is 0.5 h, the median particle size of the black powder is 40 μm, and finally manganese carbonate, cobalt carbonate, nickel carbonate and lithium carbonate are obtained.

[0082] Example 15

[0083] The difference from Example 1 is that the mass ratio of 98% acid to decomposition product is 1:10, the acid leaching temperature is 50°C, and the acid leaching time is 1 hour, ultimately yielding manganese carbonate, cobalt carbonate, nickel carbonate, and lithium carbonate.

[0084] Example 16

[0085] The difference from Example 1 is that the mass ratio of 98% acid to decomposition product is 1:20, the acid leaching temperature is 60°C, and the acid leaching time is 0.5 h, ultimately yielding manganese carbonate, cobalt carbonate, nickel carbonate, and lithium carbonate.

[0086] Comparative Example 1

[0087] The difference from Example 1 is that the use of A. monosulfide oxidizing bacteria solution to decompose black powder was omitted, and manganese carbonate, cobalt carbonate, nickel carbonate and lithium carbonate were finally obtained.

[0088] The manganese carbonate, cobalt carbonate, nickel carbonate, and lithium carbonate prepared in the examples and comparative examples were tested for manganese, cobalt, nickel, and lithium recovery rates, as well as the purity of manganese carbonate, cobalt carbonate, nickel carbonate, and lithium carbonate. The test results are shown in Table 1.

[0089] Table 1

[0090]

[0091] As can be seen from the above description, the embodiments of this application achieve the following technical effects:

[0092] In step S1, the lithium battery recycled material is disassembled and crushed sequentially, which helps to separate materials containing recycled elements. Organic components are removed through heat treatment, and magnetic impurities such as Fe are removed through demagnetization. In step S2, acidophilic bacteria solution is used to decompose the black powder, which helps to remove copper and aluminum elements, thereby improving the purity and yield of the recycled metals. In step S3, the decomposed material is acid-leached to dissolve manganese, cobalt, nickel, and lithium, obtaining a leachate. In step S4, manganese, cobalt, nickel, and lithium in the leachate are effectively separated through fractional extraction. This application effectively recovers nickel, cobalt, manganese, and lithium from lithium battery recycled material by employing a composite recycling process combining physical recycling, biological recycling, and wet recycling. In particular, the use of acidophilic bacteria for biological recycling makes the purification of metal elements more efficient. Simultaneously, fractional extraction enables selective separation of different metals. Therefore, the recycling method of this application helps to improve the purity and yield of nickel, cobalt, manganese and lithium recovery. At the same time, the recycling method of this application has good process stability, low environmental pollution and can simplify the production process and reduce raw material and production costs as needed.

[0093] The above are merely embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for recovering nickel, cobalt, manganese, and lithium, characterized in that, The recycling method includes the following steps: Step S1: The lithium battery recycled material is disassembled, crushed, heat-treated and demagnetized in sequence to obtain black powder; Step S2: The black powder is decomposed using acidophilic bacteria solution to remove copper and aluminum elements, and decomposition products are obtained. Step S3: The decomposed product is subjected to acid leaching to obtain a leachate; Step S4: The leachate is subjected to fractional extraction to obtain raffinate, manganese salt solution, cobalt salt solution and nickel salt solution; Step S5: Evaporate and crystallize the raffinate to obtain a lithium salt solution; Step S6: The manganese salt solution, the cobalt salt solution, the nickel salt solution, and the lithium salt solution are each precipitated independently to obtain manganese salt solid, cobalt salt solid, nickel salt solid, and lithium salt solid. The acidophilic bacterial solution is an A. monosulfide oxidizing bacterial solution, an Acb. disulfide oxidizing bacterial solution, or a mixed bacterial solution of A. monosulfide oxidizing bacterial solution and Acb. disulfide oxidizing bacterial solution.

2. The recycling method according to claim 1, characterized in that, In step S2, the OD600 of the acidophilic bacteria solution is 0.6~1; and / or, the mass ratio of the black powder to the volume of the acidophilic bacteria solution is 1:10~20.

3. The recycling method according to claim 1, characterized in that, In step S2, the acidophilic bacteria solution is mixed with the black powder to obtain a mixture; the pH value of the mixture is adjusted to 1~3, and then the decomposition is carried out; the decomposition time is 3~7 days; and / or the decomposition temperature is 30~50℃.

4. The recycling method according to claim 1, characterized in that, The mixed bacterial solution is composed of the A. monosulfide oxidizing bacterial solution with an OD600 of 0.6~1 and the Acb. disulfide oxidizing bacterial solution with an OD600 of 0.6~1, and the volume ratio of the A. monosulfide oxidizing bacterial solution to the Acb. disulfide oxidizing bacterial solution is 1:0.5~2.

5. The recycling method according to any one of claims 1 to 4, characterized in that, Step S4 includes: Step S41: Mix the leachate with the first extractant to obtain a first mixture. After adjusting the pH of the first mixture to 2-3, perform the first extraction and the first back-extraction sequentially to obtain the first raffinate and the manganese salt solution. Step S42: Mix the first raffinate with the second extractant to obtain a second mixture. Adjust the pH of the second mixture to 4-5, and then perform a second extraction and a second back-extraction in sequence to obtain a second raffinate and the cobalt salt solution. Step S43: Mix the second raffinate with the third extractant to obtain a third mixture. Adjust the pH of the third mixture to 7-8, and then perform a third extraction and a third back-extraction sequentially to obtain the raffinate and the nickel salt solution.

6. The recycling method according to claim 5, characterized in that, The volume ratio of the leachate to the first extractant is 1:0.1~1; and / or, the volume ratio of the first raffinate to the second extractant is 1:0.1~1; and / or, the volume ratio of the second raffinate to the third extractant is 1:0.1~1. And / or, the concentrations of the first extractant, the second extractant, and the third extractant are each independently 0.2~1 mol / L; and / or, the temperatures of the first extraction, the second extraction, and the third extraction are each independently 25~50°C; And / or, the first extractant is P204 extractant and / or A308 extractant; And / or, the second extractant is P507 extractant and / or A308 extractant; And / or, the third extractant is C272 extractant and / or A308 extractant.

7. The recycling method according to any one of claims 1 to 4, characterized in that, In step S1, the temperature of the heat treatment is 300~800℃; and / or, the time of the heat treatment is 1~8h; and / or, the median particle size of the black powder is 5~30μm.

8. The recycling method according to any one of claims 1 to 4, characterized in that, In step S3, the decomposed product is acid-leached; the mass ratio of the acid to the decomposed product is 1:1~10; and / or, the acid-leaching temperature is 20~50℃; and / or, the acid-leaching time is 1~6h; and / or, the acid is sulfuric acid and / or hydrochloric acid.

9. The recycling method according to any one of claims 1 to 4, characterized in that, In step S5, the evaporation and crystallization temperature is 80~150℃; and / or the evaporation and crystallization time is 1~6h.

10. The recycling method according to any one of claims 1 to 4, characterized in that, The precipitation temperature is 20~30℃; and / or the precipitation time is 1~6h; and / or the precipitant used in the precipitation is selected from any one or more of NH4HCO3, NaHCO3, Na2CO3 and NaOH.

Images