A method for recycling waste lithium-rich manganese-based battery materials

Abstract

This invention provides a method for recycling waste lithium-rich manganese-based battery materials. The method employs a wet extraction recovery combined with microbial extraction of metal components. First, lithium is extracted by acid leaching, yielding lithium carbonate. Then, manganese is selectively extracted using Mn-reducing bacteria, converting tetravalent manganese into divalent manganese ions. Hydroxide ions are added to precipitate manganese hydroxide. Nickel and cobalt present in the filtrate are separated using an extractant, ultimately yielding nickel sulfate and cobalt sulfate. Thus, complete recovery of lithium, manganese, nickel, and cobalt is achieved.

Description

Technical Field

[0001] This invention belongs to the field of waste lithium-ion battery material recycling technology, and particularly relates to a method for recycling waste lithium-rich manganese-based battery materials. Background Technology

[0002] Currently, recycling technologies for end-of-life lithium-ion battery materials mainly target mainstream batteries, with cathode materials primarily consisting of lithium cobalt oxide, lithium iron phosphate, and ternary materials. Some patents are beginning to explore emerging technologies such as lithium manganese iron phosphate and sodium-ion batteries, but there are few recycling solutions specifically for lithium-rich manganese-based batteries. Therefore, there is an urgent need to develop environmentally friendly and low-energy-consumption recycling methods for lithium-rich manganese-based batteries.

[0003] Currently, battery recycling technologies are mainly divided into dry and wet recycling. Dry recycling recovers valuable metal elements through high-temperature furnace incineration. Wet recycling, on the other hand, uses steps such as leaching, impurity removal, lithium precipitation, and extraction to maximize the recovery of major elements. Among these, extraction in wet recycling can achieve high-precision separation and extraction of metal elements through interactive synergy, featuring high efficiency, low energy consumption, low emissions, high recovery rate, and environmental friendliness. Currently, to improve the purity of nickel and cobalt-related products, specific extractants are needed to extract manganese. However, manganese has low recovery value, increasing the overall recycling cost. A low-cost process solution for manganese extraction is needed.

[0004] CN103620069B provides a method for recovering manganese, which involves mixing a manganese-containing material and iron-reducing bacteria into a treatment solution containing ferric ions. The iron-reducing bacteria reduce the ferric ions to ferrous ions, and the ferrous ions are used as a reducing agent to leach manganese ions from the material into the treatment solution.

[0005] In discarded lithium-rich manganese-based batteries, manganese (Mn) is mostly present in the tetravalent form. Currently, research and application of microbial transformation methods for Mn are limited, necessitating research into the application of bacteria that transform Mn(IV) in discarded batteries. This invention employs a combined wet extraction and microbial extraction scheme for metal components, combining the high extraction rate of chemical wet methods with the environmentally friendly and low-energy consumption advantages of microbial methods for the recycling of lithium-rich manganese-based batteries. Summary of the Invention

[0006] This invention provides a method for recycling waste lithium-rich manganese-based battery materials. The method employs a wet extraction recovery combined with microbial extraction of metal components. First, lithium is extracted by acid leaching, yielding lithium carbonate. Then, manganese is selectively extracted using Mn-reducing bacteria, converting tetravalent manganese into divalent manganese ions. Hydroxide ions are added to precipitate manganese hydroxide. Nickel and cobalt present in the filtrate are separated using an extractant, ultimately yielding nickel sulfate and cobalt sulfate. Thus, complete recovery of lithium, manganese, nickel, and cobalt is achieved.

[0007] Therefore, the present invention provides the following technical solution:

[0008] A method for recycling waste lithium-rich manganese-based battery materials includes the following steps: (1) Lithium extraction: The lithium-rich manganese-based cathode material is calcined and then acid-leached to obtain a lithium extraction solution; (2) Manganese extraction: Prepare filter residue 1 into a slurry, add Mn(IV) reducing bacteria culture medium, and carry out reduction leaching to convert Mn(IV) in filter residue 1 into Mn(II) to obtain manganese extraction solution and filter residue 2; (3) Nickel extraction: Add sulfuric acid and hydrogen peroxide to filter residue 2, and extract to obtain nickel sulfate solution and extract; (4) Cobalt extraction: After back-extraction of the extract, sulfuric acid is added to obtain a cobalt sulfate solution.

[0009] Lithium-rich manganese-based batteries (representing Li) 1.5 Ni 0.13 Co 0.13 Mn 0.54 O2) and ternary batteries (representing LiNi) 0.8 Co 0.1 Mn 0.1 There are significant differences in O2 content, with manganese content being 4-5 times higher and nickel and cobalt content lower. Pre-extracting nickel and cobalt products results in higher manganese impurity content because manganese readily reacts with oxygen or oxidizing substances in the solution to form precipitated manganese oxide (MnO2) or manganese hydroxide (Mn(OH)2), which are extracted along with the target product. To improve the quality of nickel and cobalt products, a more suitable recovery method is needed. This invention employs pre-extraction of manganese to reduce the manganese content in the system while ensuring low cost and minimal environmental pollution.

[0010] According to a specific embodiment of the present invention, the Mn(IV) reducing bacteria are two or more of the following: Pantotheca, Geobacterium, Shewanella, Pseudomonas, Arthrobacter, Streptomyces, Rhodococcus, and Mycobacterium.

[0011] According to a specific embodiment of the present invention, the purchased Mn(IV) reducing bacteria strain is inoculated into LB or TSB medium, the culture conditions are controlled, and the culture is expanded. After screening for viable bacteria, the Mn(IV) reducing bacteria culture solution is obtained.

[0012] According to a specific embodiment of the present invention, the reduction leaching time is 1-20 days, preferably 5-15 days.

[0013] According to a specific embodiment of the present invention, the mixture after reduction leaching is centrifuged at high speed, and the supernatant obtained is filtered by a filter membrane to obtain manganese extraction solution and filter residue 2.

[0014] Preferably, the high-speed centrifugation speed is 8000-10000 r / min and the time is 5-10 min.

[0015] According to a specific embodiment of the present invention, the calcination temperature in step (1) is 500-700℃ and the time is 2-5 h.

[0016] According to a specific embodiment of the present invention, the acid used for acid leaching in step (1) is a sulfuric acid solution with a pH of 4.5-8.

[0017] According to a specific embodiment of the present invention, in step (3), the pH value of sulfuric acid is 1-3, the amount of hydrogen peroxide added is 1-1.4 times the theoretical amount, and the extractant is P507.

[0018] According to a specific embodiment of the present invention, step (1) further includes: adding an alkaline solution to the lithium extraction solution to adjust the pH value, and then adding sodium carbonate to precipitate lithium to obtain a lithium carbonate product.

[0019] According to a specific embodiment of the present invention, step (2) further includes: adding an alkaline solution to the manganese extraction solution to precipitate manganese, filtering, and obtaining the filter residue as manganese hydroxide product.

[0020] Preferably, the alkaline solution is one or more of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate aqueous solution, and ammonia water.

[0021] According to a specific embodiment of the present invention, step (3) further includes: evaporating and crystallizing the nickel sulfate solution to obtain the nickel sulfate product.

[0022] According to a specific embodiment of the present invention, step (4) further includes: the pH value after adding sulfuric acid is 1-3, and the cobalt sulfate solution is evaporated and crystallized to obtain cobalt sulfate product.

[0023] Beneficial effects: 1. Based on the high manganese content of lithium-rich manganese-based materials, and considering that manganese is easily oxidized and precipitated, which affects the purity of nickel and cobalt related products, this invention adopts a microbial manganese extraction process to separate manganese in advance, thereby reducing the interference of high manganese content on the preparation of nickel and cobalt products and improving the quality of cobalt and nickel products. 2. In battery recycling, nickel, cobalt, and other related products have high economic value, while manganese has relatively low value. To improve the purity of nickel and cobalt-related products, it is necessary to add a manganese-specific extractant and use specific processes to extract manganese. This is especially true for lithium-rich manganese-based materials, which have a high manganese content, requiring more manganese extractant and reducing overall profits. This invention uses microbial manganese extraction technology to replace manganese extractants, improving the overall environmental friendliness and economy of the process. Attached Figure Description

[0024] Figure 1 This is a flowchart illustrating the recycling of waste lithium-rich manganese-based battery materials, provided as an embodiment of the present invention. Detailed Implementation

[0025] To make the technical problems solved, the technical solutions, and the beneficial effects of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0026] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0027] The method for recycling and utilizing waste lithium-rich manganese-based battery materials provided by this invention includes the following steps: (0) Preprocessing After pretreatment such as discharge and disassembly, the waste lithium-rich manganese-based battery is used to obtain lithium-rich manganese-based positive electrode material. Alkali solution 1 was added to the lithium-rich manganese-based positive electrode material to leach out aluminum. After filtration, the filter residue was calcined to remove carbon and fluorine, and the calcined material was obtained.

[0028] Wherein, the alkaline solution 1 is an aqueous solution of sodium hydroxide with a concentration of 2-4 mol / L, a pH value of 8.5-10, and a liquid-to-solid ratio of 10-30:1; The calcination temperature is 500-700℃, such as 500℃, 550℃, 600℃, 650℃, 700℃, etc.; the calcination time is 2-5 h, such as 2 h, 3 h, 4 h, 5 h, etc.

[0029] (1) Lithium extraction Sulfuric acid was added to the above calcined material for leaching to obtain filter residue 1 and lithium extraction solution; Alkali solution 2 was added to the lithium extraction solution to adjust the pH value, and then sodium carbonate was added to precipitate lithium to obtain lithium carbonate product.

[0030] The pH value of the sulfuric acid solution is 4.5-6.5; the amount of sulfuric acid added is such that the liquid-solid ratio of the leaching system is (4-8):1. The alkaline solution 2 is an aqueous solution of sodium hydroxide with a concentration of 2-4 mol / L, a system pH of 10-12, and the amount of sodium carbonate added is 1-3.5 times the theoretical amount.

[0031] (2) Manganese extraction Expanding the culture: The purchased Mn(IV)-reducing bacteria strain was inoculated into LB or TSB medium, and cultured under controlled conditions for expansion. Viable bacteria were then screened to obtain the Mn(IV)-reducing bacteria culture broth. The Mn(IV)-reducing bacteria were selected from two or more of the following genera: *Panthera*, *Geobacterium*, *Shewanella*, *Pseudomonas*, *Arthrobacter*, *Streptomyces*, *Rhodococcus*, and *Mycobacterium*. All of the above strains can be purchased from the China General Microbiological Culture Collection Center (CGMCC).

[0032] Add water to the filter residue 1 obtained in step (1) to prepare a slurry, control the Mn(IV) concentration to be 100-300 mg / L, add Mn(IV) reducing bacteria culture medium, the inoculum amount is 1-15%, and carry out reduction leaching (constant temperature 20-40℃, pH=6-9) to convert Mn(IV) in the filter residue into Mn(II). After leaching for 1-20 days, preferably 5-15 days, centrifuge the mixture after reduction leaching at high speed, and filter the supernatant obtained by filter membrane to obtain manganese extraction solution and filter residue 2. The high-speed centrifugation speed is 8000-10000 r / min, and the time is 5-10 min.

[0033] Add alkali solution 3 to the manganese extraction solution obtained above to carry out the manganese precipitation reaction, filter, and the filter residue obtained is manganese hydroxide product.

[0034] The alkaline solution 3 is an aqueous solution of sodium hydroxide with a concentration of 2-4 mol / L and a pH value of 9-12.

[0035] (3) Nickel extraction Sulfuric acid and hydrogen peroxide were added to the filter residue 2 obtained in step (2), and nickel sulfate solution and extract were obtained after extraction. The nickel sulfate solution was evaporated and crystallized to obtain nickel sulfate product.

[0036] The sulfuric acid has a pH of 1-3, the amount of hydrogen peroxide added is 1-1.4 times the theoretical amount, and the extractant is P507.

[0037] (4) Cobalt extraction The extract obtained in step (3) is back-extracted and then sulfuric acid is added to obtain a cobalt sulfate solution; the cobalt sulfate solution is then evaporated and crystallized to obtain the cobalt sulfate product. The pH value after adding sulfuric acid is 1-3.

[0038] The following are specific embodiments of the present invention.

[0039] Example 1 like Figure 1 As shown, the method for recycling and utilizing waste lithium-rich manganese-based batteries in this embodiment includes the following steps: (1) After the waste lithium-rich manganese-based battery is pretreated by discharge and dismantling, lithium-rich manganese-based positive electrode material is obtained.

[0040] (2) Add pure water and 4 mol / L sodium hydroxide to the lithium-rich manganese-based positive electrode material, adjust the pH value to 9.5, leach out aluminum, filter, calcine the filter residue to remove carbon and fluorine, and obtain calcined material.

[0041] (3) Add sulfuric acid with a pH of 5 to the calcined material, with a liquid-to-solid ratio of 6:1, to obtain filter residue 1 and lithium extraction liquid. After adjusting the pH of the lithium extraction liquid to 10 with 4 mol / L sodium hydroxide, add twice the theoretical amount of sodium carbonate to precipitate lithium to obtain lithium carbonate product.

[0042] (4) Add Pantotheca, Geobacterium and Shewanella to the culture medium respectively, carry out large-scale culture and screen live bacteria, mix them to obtain Mn(IV) reducing bacteria culture medium, named X-ZKMN01.

[0043] (5) Add Mn(IV) reducing bacteria X-ZKMN01 culture medium to the filter residue 1 prepared into slurry for reduction leaching, converting the tetravalent manganese in the filter residue into divalent manganese. After reduction leaching for 5 days at a constant temperature of 35℃ and a pH of 7, centrifuge at high speed. Filter the supernatant obtained by centrifugation with a filter membrane. Collect the manganese extraction solution and filter residue 2. Take a sample of the manganese extraction solution and detect the Mn(II) concentration by atomic absorption spectrometry to determine the manganese extraction rate and judge the reduction effect.

[0044] (6) Add 4 mol / L sodium hydroxide to the manganese extraction solution in step 5, adjust the pH to 10, precipitate, filter, and obtain filtrate. The filter residue is manganese hydroxide product.

[0045] (7) Add sulfuric acid with pH 3 and hydrogen peroxide with a theoretical amount of 1.15 times to the filter residue 2 collected in step 5 to obtain a solution. Add extractant P507 to the solution to obtain nickel sulfate solution and extract. Evaporate the nickel sulfate solution to crystallize and obtain nickel sulfate product.

[0046] (8) After back-extracting the extract collected in step 7, sulfuric acid is added to adjust the pH to 3 to obtain a cobalt sulfate solution. The cobalt sulfate solution is evaporated and crystallized to obtain the cobalt sulfate product.

[0047] Example 2 The method for recycling and utilizing waste lithium-rich manganese-based batteries in this embodiment includes the following steps: (1) After the waste lithium-rich manganese-based battery is pretreated by discharge and dismantling, lithium-rich manganese-based positive electrode material is obtained.

[0048] (2) Add pure water and 4 mol / L sodium hydroxide to the lithium-rich manganese-based positive electrode material, adjust the pH value to 9.5, leach out aluminum, filter, calcine the filter residue to remove carbon and fluorine, and obtain calcined material.

[0049] (3) Add sulfuric acid with a pH of 5 to the calcined material, with a liquid-to-solid ratio of 6:1, to obtain filter residue 1 and lithium extraction liquid. After adjusting the pH of the lithium extraction liquid to 10 with 4 mol / L sodium hydroxide, add twice the theoretical amount of sodium carbonate to precipitate lithium to obtain lithium carbonate product.

[0050] (4) Add Pantotheca, Geobacterium and Shewanella to the culture medium respectively, carry out large-scale culture and screen live bacteria, mix them to obtain Mn(IV) reducing bacteria culture medium, named X-ZKMN01.

[0051] (5) Add Mn(IV) reducing bacteria X-ZKMN01 culture medium to the filter residue 1 prepared into slurry for reduction leaching, converting the tetravalent manganese in the filter residue into divalent manganese. After reduction leaching for 10 days at a constant temperature of 35℃ and a pH of 7, centrifuge at high speed. Filter the supernatant obtained by centrifugation with a filter membrane. Collect the manganese extraction solution and filter residue 2. Take a sample of the manganese extraction solution and detect the Mn(II) concentration by atomic absorption spectrometry to determine the manganese extraction rate and judge the reduction effect.

[0052] (6) Add 4 mol / L sodium hydroxide to the manganese extraction solution in step 5, adjust the pH to 10, precipitate, filter, and obtain filtrate. The filter residue is manganese hydroxide product.

[0053] (7) Add sulfuric acid with pH 3 and hydrogen peroxide with a theoretical amount of 1.15 times to the filter residue 2 collected in step 5 to obtain a solution. Add extractant P507 to the solution to obtain nickel sulfate solution and extract. Evaporate the nickel sulfate solution to crystallize and obtain nickel sulfate product.

[0054] (8) After back-extracting the extract collected in step 7, sulfuric acid is added to adjust the pH to 3 to obtain a cobalt sulfate solution. The cobalt sulfate solution is evaporated and crystallized to obtain the cobalt sulfate product.

[0055] Example 3 like Figure 1 As shown, the method for recycling and utilizing waste lithium-rich manganese-based batteries in this embodiment includes the following steps: (1) After the waste lithium-rich manganese-based battery is pretreated by discharge and dismantling, lithium-rich manganese-based positive electrode material is obtained.

[0056] (2) Add pure water and 4 mol / L sodium hydroxide to the lithium-rich manganese-based positive electrode material, adjust the pH value to 9.5, leach out aluminum, filter, calcine the filter residue to remove carbon and fluorine, and obtain calcined material.

[0057] (3) Add sulfuric acid with a pH of 5 to the calcined material, with a liquid-to-solid ratio of 6:1, to obtain filter residue 1 and lithium extraction liquid. After adjusting the pH of the lithium extraction liquid to 10 with 4 mol / L sodium hydroxide, add twice the theoretical amount of sodium carbonate to precipitate lithium to obtain lithium carbonate product.

[0058] (4) Add Pantotheca, Geobacterium and Shewanella to the culture medium respectively, carry out large-scale culture and screen live bacteria, mix them to obtain Mn(IV) reducing bacteria culture medium, named X-ZKMN01.

[0059] (5) Add Mn(IV) reducing bacteria X-ZKMN01 culture medium to the filter residue 1 prepared into slurry for reduction leaching, converting the tetravalent manganese in the filter residue into divalent manganese. After reduction leaching for 15 days at a constant temperature of 35℃ and a pH of 7, centrifuge at high speed. Filter the supernatant obtained by centrifugation with a filter membrane. Collect the manganese extraction solution and filter residue 2. Take a sample of the manganese extraction solution and detect the Mn(II) concentration by atomic absorption spectrometry to determine the manganese extraction rate and judge the reduction effect.

[0060] (6) Add 4 mol / L sodium hydroxide to the manganese extraction solution in step 5, adjust the pH to 10, precipitate, filter, and obtain filtrate. The filter residue is manganese hydroxide product.

[0061] (7) Add sulfuric acid with pH 3 and hydrogen peroxide with a theoretical amount of 1.15 times to the filter residue 2 collected in step 5 to obtain a solution. Add extractant P507 to the solution to obtain nickel sulfate solution and extract. Evaporate the nickel sulfate solution to crystallize and obtain nickel sulfate product.

[0062] (8) After back-extracting the extract collected in step 7, sulfuric acid is added to adjust the pH to 3 to obtain a cobalt sulfate solution. The cobalt sulfate solution is evaporated and crystallized to obtain the cobalt sulfate product.

[0063] Example 4 like Figure 1 As shown, the method for recycling and utilizing waste lithium-rich manganese-based batteries in this embodiment includes the following steps: (1) After the waste lithium-rich manganese-based battery is pretreated by discharge and dismantling, lithium-rich manganese-based positive electrode material is obtained.

[0064] (2) Add pure water and 4 mol / L sodium hydroxide to the lithium-rich manganese-based positive electrode material, adjust the pH value to 9.5, leach out aluminum, filter, calcine the filter residue to remove carbon and fluorine, and obtain calcined material.

[0065] (3) Add sulfuric acid with a pH of 5 to the calcined material, with a liquid-to-solid ratio of 6:1, to obtain filter residue 1 and lithium extraction liquid. After adjusting the pH of the lithium extraction liquid to 10 with 4 mol / L sodium hydroxide, add twice the theoretical amount of sodium carbonate to precipitate lithium to obtain lithium carbonate product.

[0066] (4) Add Geyserum and Shewanella to the culture medium respectively, carry out large-scale culture, screen for viable bacteria, mix them to obtain Mn(IV) reducing bacteria culture medium, named X-ZKMN02.

[0067] (5) Add Mn(IV) reducing bacteria X-ZKMN02 culture medium to the filter residue 1 to carry out reduction leaching, converting the tetravalent manganese in the filter residue into divalent manganese. After reduction leaching for 15 days at a constant temperature of 35℃ and a pH of 7, centrifuge at high speed. Filter the supernatant obtained by centrifugation with a filter membrane. Collect the manganese extraction solution and filter residue 2. Take a sample of the manganese extraction solution and detect the Mn(II) concentration by atomic absorption spectrometry to determine the manganese extraction rate and judge the reduction effect.

[0068] (6) Add 4 mol / L sodium hydroxide to the manganese extraction solution in step 5, adjust the pH to 10, precipitate, filter, and obtain filtrate. The filter residue is manganese hydroxide product.

[0069] (7) Add sulfuric acid with pH 3 and hydrogen peroxide with a theoretical amount of 1.15 times to the filter residue 2 collected in step 5 to obtain a solution. Add extractant P507 to the solution to obtain nickel sulfate solution and extract. Evaporate the nickel sulfate solution to crystallize and obtain nickel sulfate product.

[0070] (8) After back-extracting the extract collected in step 7, sulfuric acid is added to adjust the pH to 3 to obtain a cobalt sulfate solution. The cobalt sulfate solution is evaporated and crystallized to obtain the cobalt sulfate product.

[0071] Example 5 like Figure 1 As shown, the method for recycling and utilizing waste lithium-rich manganese-based batteries in this embodiment includes the following steps: (1) After the waste lithium-rich manganese-based battery is pretreated by discharge and dismantling, lithium-rich manganese-based positive electrode material is obtained.

[0072] (2) Add pure water and 4 mol / L sodium hydroxide to the lithium-rich manganese-based positive electrode material, adjust the pH value to 9.5, leach out aluminum, filter, calcine the filter residue to remove carbon and fluorine, and obtain calcined material.

[0073] (3) Add sulfuric acid with a pH of 5 to the calcined material, with a liquid-to-solid ratio of 6:1, to obtain filter residue 1 and lithium extraction liquid. After adjusting the pH of the lithium extraction liquid to 10 with 4 mol / L sodium hydroxide, add twice the theoretical amount of sodium carbonate to precipitate lithium to obtain lithium carbonate product.

[0074] (4) Add Pantotheca and Geobacterium to the culture medium respectively, carry out large-scale culture, screen live bacteria, mix them to obtain Mn(IV) reducing bacteria culture medium, named X-ZKMN03.

[0075] (5) Add Mn(IV) reducing bacteria X-ZKMN03 culture medium to the filter residue 1 to perform reduction leaching, converting the tetravalent manganese in the filter residue into divalent manganese. After reduction leaching for 15 days at a constant temperature of 35℃ and a pH of 7, centrifuge at high speed. Filter the supernatant obtained by centrifugation with a filter membrane. Collect the manganese extraction solution and filter residue 2. Take a sample of the manganese extraction solution and detect the Mn(II) concentration by atomic absorption spectrometry to determine the manganese extraction rate and judge the reduction effect.

[0076] (6) Add 4 mol / L sodium hydroxide to the manganese extraction solution in step 5, adjust the pH to 10, precipitate, filter, and obtain filtrate. The filter residue is manganese hydroxide product.

[0077] (7) Add sulfuric acid with pH 3 and hydrogen peroxide with a theoretical amount of 1.15 times to the filter residue 2 collected in step 5 to obtain a solution. Add extractant P507 to the solution to obtain nickel sulfate solution and extract. Evaporate the nickel sulfate solution to crystallize and obtain nickel sulfate product.

[0078] (8) After back-extracting the extract collected in step 7, sulfuric acid is added to adjust the pH to 3 to obtain a cobalt sulfate solution. The cobalt sulfate solution is evaporated and crystallized to obtain the cobalt sulfate product.

[0079] Comparative Example 1 The method for recycling and reusing spent lithium-rich manganese-based batteries, as described in Comparative Example 1, includes the following steps: (1) After the waste lithium-rich manganese-based battery is pretreated by discharge and dismantling, lithium-rich manganese-based positive electrode material is obtained.

[0080] (2) Add pure water and 4 mol / L sodium hydroxide to the lithium-rich manganese-based positive electrode material, adjust the pH value to 9.5, leach out aluminum, filter, calcine the filter residue to remove carbon and fluorine, and obtain calcined material.

[0081] (3) Add sulfuric acid with a pH of 5 to the calcined material, with a liquid-to-solid ratio of 6:1, to obtain filter residue 1 and lithium extraction liquid. After adjusting the pH of the lithium extraction liquid to 10 with 4 mol / L sodium hydroxide, add twice the theoretical amount of sodium carbonate to precipitate lithium to obtain lithium carbonate product.

[0082] (4) Add sulfuric acid with pH 3 and hydrogen peroxide 1.15 times the theoretical amount to the filter residue from step 3. A solution is obtained. Extractant P204 is added to the solution to obtain the residual liquid and manganese-containing extract. After back-extraction of the manganese-containing extract, sulfuric acid is added to adjust the pH to 3 to obtain a manganese sulfate solution. The manganese sulfate solution is evaporated and crystallized to obtain the manganese sulfate product.

[0083] (5) Add extractant P507 to the residual liquid collected in step 4 to obtain nickel sulfate solution and cobalt-containing extract. Evaporate the nickel sulfate solution to obtain nickel sulfate product.

[0084] (6) After back-extracting the extract collected in step 5, sulfuric acid is added to adjust the pH to 3 to obtain a cobalt sulfate solution. The cobalt sulfate solution is evaporated and crystallized to obtain the cobalt sulfate product.

[0085] Comparative Example 2 The difference between this comparative example and Example 3 is that Pantotheca, Geobacterium, and Shewanella were replaced with Trichophyton, and the resulting Mn(IV)-reducing bacterial culture was named X-ZKMN04. The rest of the operations are the same.

[0086] Comparative Example 3 The difference between this comparative example and Example 3 is that Pantotheca, Geobacterium, and Shewanella were replaced with a single Geobacterium, and the resulting Mn(IV) reducing bacteria culture was named X-ZKMN05. The rest of the operations are the same.

[0087] The purity of the products obtained from the above embodiments and comparative examples was tested, and the leaching rate of manganese was calculated. The results are shown in Table 1.

[0088] Table 1

[0089] As can be seen from the table, the reducing bacteria provided by this invention can effectively convert tetravalent Mn(IV) into divalent Mn(II). Compared with the conventional manganese extraction process using extractants (Comparative Example 1), on the one hand, extractants are expensive and highly polluting, while microbial reduction technology is pollution-free and cheaper; on the other hand, Example 3, compared with the comparative example, has advantages such as high manganese leaching rate and high product purity, improving the overall environmental friendliness and economy of the process. Compared with other bacterial strains (Comparative Example 2), the reducing bacteria provided by this invention have a better reduction leaching effect (Comparative Example 3); compared with single bacterial strain reduction, the effect of mixed strains of two or more strains is the best.

[0090] The specific embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0091] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

Claims

1. A method for recycling and utilizing waste lithium-rich manganese-based battery materials, characterized in that, Includes the following steps: (1) Lithium extraction: The lithium-rich manganese-based cathode material is calcined and then acid-leached to obtain filter residue 1 and lithium extraction solution; (2) Manganese extraction: Prepare filter residue 1 into a slurry, add Mn(IV) reducing bacteria culture medium, and carry out reduction leaching to convert Mn(IV) in filter residue 1 into Mn(II) to obtain manganese extraction solution and filter residue 2. The Mn(IV) reducing bacteria are two or more of Pantotheca, Geobacterium, and Shewanella. (3) Nickel extraction: Add sulfuric acid and hydrogen peroxide to filter residue 2, and extract to obtain nickel sulfate solution and extract; (4) Cobalt extraction: After back-extraction of the extract, sulfuric acid is added to obtain a cobalt sulfate solution.

2. The method according to claim 1, characterized in that, The reduction leaching time is 1-20 days.

3. The method according to claim 1, characterized in that, The mixture after reduction leaching is centrifuged at high speed, and the supernatant is filtered through a filter membrane to obtain manganese extraction solution and filter residue 2.

4. The method according to claim 3, characterized in that, The high-speed centrifugation speed is 8000-10000 r / min, and the time is 5-10 min.

5. The method according to claim 1, characterized in that, The calcination temperature in step (1) is 500-700℃ and the time is 2-5 h; The acid used for acid leaching is a sulfuric acid solution with a pH of 4.5-8.

6. The method according to claim 1, characterized in that, Step (1) further includes: adding alkali to the lithium extraction solution to adjust the pH value, and then adding sodium carbonate to precipitate lithium to obtain lithium carbonate product.

7. The method according to claim 1, characterized in that, Step (2) further includes: adding alkaline solution to the manganese extraction solution to precipitate manganese, filtering, and obtaining filter residue as manganese hydroxide product.

8. The method according to claim 7, characterized in that, The alkaline solution is one or more of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate aqueous solution, and ammonia water.

9. The method according to claim 1, characterized in that, In step (3), the pH value of sulfuric acid is 1-3, the amount of hydrogen peroxide added is 1-1.4 times the theoretical amount, and the extractant is P507.

10. The method according to claim 1, characterized in that, Step (3) further includes: evaporating and crystallizing the nickel sulfate solution to obtain the nickel sulfate product.

11. The method according to claim 1, characterized in that, Step (4) further includes: evaporating and crystallizing the cobalt sulfate solution to obtain the cobalt sulfate product.

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