Method for recovering valuable metals Li, Ni, Co and Mn from waste ternary lithium ion battery positive electrode material

Abstract

The invention discloses a method for recycling valuable metals Li, Ni, Co and Mn in a waste ternary lithium ion battery positive electrode material, which comprises the following steps: (1) obtaining the waste ternary lithium ion battery positive electrode material, roasting, then adding methanesulfonic acid and ascorbic acid for mixing reaction, and filtering; (2) adding dimethylglyoxime into the leachate to complex and precipitate Ni < 2 + >, and filtering to obtain filtrate 1 and filter residues; (3) adjusting the pH value of the filtrate 1, precipitating Co < 2 + > by adopting ammonium sulfide, and filtering to obtain filtrate 2 and filter residues; (4) adjusting the pH value of the filtrate 2, precipitating Mn < 2 + >, and filtering to obtain filtrate 3 and filter residues; and (5) adding phosphate into the filtrate 3 to precipitate Li < + >, and filtering to obtain filtrate 4 and filter residues. According to the method, a good leaching effect is achieved under the conditions that the acid concentration is low, the temperature is low, and the leaching reaction time is short, and the follow-up steps for separating and recycling the metal in the leaching liquid are short. The method is high in recovery efficiency, short in period, simple in process and suitable for industrial application production.

Description

Technical Field

[0001] The invention relates to the technical field of waste battery recycling, and in particular to a method for recycling valuable metals Li, Ni, Co and Mn in positive electrode materials of waste ternary lithium-ion batteries. Background Art

[0002] Lithium-ion batteries are widely used in various electronic products, home appliances, electric vehicles and other fields due to their high energy density, high battery voltage, good reversibility, low self-discharge and no memory effect. The life of lithium-ion batteries is about 3-5 years. With the continuous improvement of people's living standards, the demand for various electronic products, home appliances and electric vehicles has increased, resulting in a surge in the number of waste lithium-ion batteries. Ternary lithium-ion batteries (NCM) combine the advantages of other types of lithium-ion batteries, contain nickel, cobalt and manganese transition metal elements, and have the highest market share in major domestic markets. Waste ternary lithium-ion batteries contain not only a large amount of valuable metals, but also harmful components. If these discarded lithium-ion batteries are not effectively disposed of, the metals such as lithium, nickel, cobalt and manganese in the ternary lithium-ion batteries and the electrolyte may cause certain harm to human health and the environment, and will seriously waste precious resources.

[0003] At present, the main methods for recovering valuable metals from waste ternary lithium-ion batteries are pyrometallurgy and hydrometallurgy. Pyrometallurgy produces a lot of waste gas and has the disadvantages of high energy consumption, while hydrometallurgy can recover most of the components in waste ternary lithium-ion batteries. The recovered products are of high purity and have mild operating conditions. Inorganic acids such as H are usually used in the hydrometallurgical process. 2 SO 4 , HCl and HNO 3 Almost 99% of valuable metals can be recovered from waste ternary lithium-ion batteries. However, in the process of leaching with inorganic acids, toxic and harmful gases will inevitably be produced and the equipment will be highly corrosive. In recent years, the use of organic acid leaching technology has received widespread attention, such as succinic acid, malic acid, citric acid, lactic acid, and tartaric acid. Although these organic acids are mild, their acidity is very weak, resulting in the leaching process requiring low solid-liquid ratio, high acid concentration, high temperature, and long leaching reaction time. However, methanesulfonic acid is the most acidic of organic acids, and its acidity is comparable to that of inorganic acids (such as HNO 3 ) is equivalent to methanesulfonic acid as a leaching agent, and a good leaching effect can be obtained under the conditions of low acid concentration, low temperature and short leaching reaction time. At the same time, nickel, cobalt or manganese in waste ternary lithium-ion batteries are usually in a high valence state and have stable chemical properties. A reducing agent is required to reduce them from a high valence state to a low valence state to promote the leaching of metals from the material. Hydrogen peroxide, glucose, ascorbic acid, etc. are usually used as reducing agents, but hydrogen peroxide is unstable and easy to decompose. Ascorbic acid can be used as both a reducing agent and a leaching agent.

[0004] At the same time, there are many types of mixed valuable metals in the leachate, and their chemical properties are similar, making further recovery another problem. The valuable metals after leaching coexist in the leachate in the form of ions. The mixed metal ions in the leachate still need to be further purified and extracted to achieve the sustainability of resource recycling. However, the recovery methods of mixed metals in the leachate can be divided into regeneration recovery and separation recovery. Regeneration recovery refers to the use of mixed metal ions in the leachate as raw materials to prepare new positive electrode materials through a series of methods. Separation recovery refers to the separation of mixed metal ions in the leachate one by one by adding a series of reagents, and recycling them as products in the form of metal compounds. The positive electrode material precursor regenerated by regeneration recovery has a high impurity content, the performance of the prepared positive electrode material is poor, and it even fails to meet the requirements of commercial use, and the energy consumption is high. However, separation recovery has low energy consumption, low cost, high product purity, and higher commercial value.

[0005] Common methods for separation and recovery include chemical precipitation and solvent extraction. Most of the metal ions separated and recovered by solvent extraction are present in the organic phase, so solvent extraction is usually used in conjunction with chemical precipitation. The recovery cost of solvent extraction is relatively high, and the extractant is toxic. In addition, it is often necessary to use it in conjunction with chemical precipitation, which will increase the recovery process to a certain extent. However, chemical precipitation has simple steps and low cost. Existing chemical precipitation methods have some problems, such as the difficulty in separating valuable metals in the leachate and the low purity of the obtained product.

[0006] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention and should not be regarded as an acknowledgment or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the invention

[0007] The object of the present invention is to provide a method for recovering valuable metals Li, Ni, Co and Mn in the positive electrode materials of waste ternary lithium ion batteries, thereby overcoming the disadvantages of high acid concentration, high temperature, long leaching reaction time, low leaching rate, difficulty in separating valuable metals in the leachate, high energy consumption and low purity of the obtained product when recovering valuable metals.

[0008] To achieve the above object, the present invention provides a method for recovering valuable metals Li, Ni, Co and Mn in the positive electrode material of waste ternary lithium-ion batteries, comprising the following steps:

[0009] (1) obtaining waste ternary lithium-ion battery positive electrode materials, roasting, then adding methanesulfonic acid and ascorbic acid to mix and react, filtering, and obtaining a valuable metal leaching solution;

[0010] (2) Add diacetyl oxime to the leaching solution of step (1) to precipitate Ni 2+After the reaction is complete, the filtrate 1 and the filter residue are obtained, and the filter residue is washed several times to obtain nickel diacetate;

[0011] (3) Adjust the pH of filtrate 1 and precipitate Co using ammonium sulfide 2+ After the reaction is complete, the mixture is filtered to obtain filtrate 2 and filter residue, and the filter residue is cobalt sulfide after multiple washings;

[0012] (4) Adjust the pH of filtrate 2 to precipitate Mn 2+ After the reaction is complete, the mixture is filtered to obtain filtrate 3 and filter residue, which is manganese sulfide after being washed several times;

[0013] (5) Add phosphate to filtrate 3 to precipitate Li + After the reaction is complete, filter to obtain filtrate 4 and filter residue, which is trilithium phosphate after multiple washings.

[0014] Preferably, in the above technical solution, the calcination in step (1) is carried out at 450-600° C. for 1-10 h.

[0015] Preferably, in the above technical solution, the concentration of methanesulfonic acid in step (1) is 0.2-1.1 mol / L, the concentration of ascorbic acid is 0.02-0.16 mol / L, the solid-liquid ratio of the reaction system is 10-50 g / L, and the leaching reaction is carried out at 30-80° C. for 2-30 min.

[0016] Preferably, in the above technical solution, in step (2), dimethylglyoxime and Ni 2+ The molar ratio is 1:2-5:1, the pH of the complex precipitation reaction is 2-7, and the reaction is carried out at 30-80°C for 5-90 minutes.

[0017] Preferably, in the above technical solution, the ammonium sulfide in step (3) is an undiluted analytically pure ammonium sulfide solution, the volume percentage V / V of the undiluted ammonium sulfide added is 0.5-12%, the pH of the precipitation reaction is 1-6, and the reaction is carried out at 30-80°C for 5-50 minutes.

[0018] Preferably, in the above technical solution, step (4) adjusts the pH of the filtrate 2 and uses ammonium sulfide to precipitate Mn 2+ The ammonium sulfide is an undiluted analytical pure ammonium sulfide solution, the volume percentage V / V of the undiluted ammonium sulfide added is 0-5%, the pH of the precipitation reaction is 5-11, and the reaction is carried out at 30-80°C for 5-50 minutes.

[0019] Step (3) and step (4) use the same reagent ammonium sulfide to precipitate and separate and recover cobalt and manganese. The raw material for the step of precipitating and recovering manganese comes from the filtrate of the step (3) of precipitating and recovering cobalt. There will be a small amount of ammonium sulfide remaining in the filtrate. Therefore, this step considers the effect of precipitating and recovering manganese without adding ammonium sulfide and only changing the pH conditions. Whether to add ammonium sulfide in step (4) is selected according to actual needs.

[0020] Preferably, in the above technical solution, in step (5), the phosphate and Li 2+ The molar ratio is 0.2:1-1.2:1, the pH of the precipitation reaction is 5-10, and the reaction is carried out at 60-95°C for 30-90 minutes.

[0021] Preferably, in the above technical scheme, the phosphate in step (5) is one or more of sodium dihydrogen phosphate, potassium dihydrogen phosphate, disodium hydrogen phosphate, diammonium hydrogen phosphate, trisodium phosphate, sodium pyrophosphate, calcium pyrophosphate, sodium tripolyphosphate, sodium hexametaphosphate, sodium metaphosphate or sodium polyphosphate; preferably trisodium phosphate.

[0022] Preferably, in the above technical solution, after the filter residues in step (3), step (4) and step (5) are rinsed, they are dried at 50-70° C. for 10-48 hours.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] (1) The method for recovering valuable metals Li, Ni, Co and Mn in the positive electrode material of waste ternary lithium ion batteries of the present invention adopts a methanesulfonic acid-ascorbic acid system to leach valuable metals, wherein methanesulfonic acid is a leaching agent, and ascorbic acid is a leaching agent and a reducing agent to leach valuable metals Li, Ni, Co and Mn in the positive electrode material of waste ternary lithium ion batteries; and then a chemical precipitation method is adopted to selectively precipitate and separate valuable metals Li, Ni, Co and Mn in the leachate. First, Ni is separated by diacetyl oxime complex precipitation, and then Co is separated by ammonium sulfide precipitation by adjusting the pH of the solution, and Mn is separated by ammonium sulfide precipitation again by adjusting the pH of the solution, and finally Li is separated by trisodium phosphate precipitation. The advantage of the method of the present invention is that a good leaching effect can be obtained under the conditions of low acid concentration, low temperature and short leaching reaction time, and the subsequent steps of metal separation and recovery of the leachate are relatively simple and brief. The same reagent can be used to selectively separate multiple metals by adjusting the pH. In general, the method has the advantages of high recovery efficiency, short cycle, simple process, further shortened process flow, reduced secondary pollution, etc., and is suitable for industrial application production.

[0025] (2) The method of the present invention is based on the premise of achieving higher environmental and economic benefits, providing a new idea for recycling waste ternary lithium-ion batteries, and ultimately providing technical support for industrial application. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is an XRD diagram of a Ni precipitation product in the method for recovering valuable metals Li, Ni, Co and Mn in the positive electrode material of waste ternary lithium-ion batteries according to Example 1 of the present invention;

[0027] Figure 2 is an XRD diagram of a Co precipitated product in the method for recovering valuable metals Li, Ni, Co and Mn in the positive electrode material of waste ternary lithium-ion batteries according to Example 1 of the present invention;

[0028] Figure 3 is an XRD diagram of a Mn precipitate product in the method for recovering valuable metals Li, Ni, Co and Mn in the positive electrode material of waste ternary lithium-ion batteries according to Example 1 of the present invention;

[0029] Figure 4 1 is an XRD diagram of a Li precipitation product in the method for recovering valuable metals Li, Ni, Co and Mn in the positive electrode material of waste ternary lithium-ion batteries according to Example 1 of the present invention. DETAILED DESCRIPTION

[0030] The specific implementation modes of the present invention are described in detail below in conjunction with the accompanying drawings, but it should be understood that the protection scope of the present invention is not limited by the specific implementation modes.

[0031] Unless explicitly stated otherwise, throughout the specification and claims, the term “comprise” or variations such as “include” or “comprising”, etc., will be understood to include the stated elements or components but not to exclude other elements or components.

[0032] Obtaining raw materials

[0033] The waste ternary lithium-ion battery was disassembled, the positive and negative electrode materials were separated, the positive electrode material was roasted at 520°C for 3h to remove the binder, and then passed through a 200-mesh sieve. Among them, the type of waste ternary lithium-ion battery is lithium nickel cobalt manganese oxide. The raw material composition (W / %) of the obtained waste ternary lithium-ion battery positive electrode material is shown in Table 1.

[0034] Table 1 Raw material composition (w / %)

[0035]

[0036] Example 1

[0037] Using the raw materials obtained above to carry out leaching reaction experiments, a method for recovering valuable metals Li, Ni, Co and Mn in the positive electrode materials of waste ternary lithium-ion batteries comprises the following steps:

[0038] 1. Preparation of leachate

[0039] (1) Prepare a mixed solution of methanesulfonic acid and ascorbic acid of required concentration, and take 0.4 g of pretreated lithium-ion battery positive electrode material.

[0040] (2) Add 20 mL of mixed acid (0.6 mol / L methanesulfonic acid and 0.1 mol / L ascorbic acid) to the positive electrode material and react at a temperature of 40°C and a rotation speed of 200 r / min for 10 min.

[0041] (3) The leachate is filtered to obtain a valuable metal leachate, and the contents of Li, Ni, Co, and Mn in the leachate are measured to obtain the leaching rate. As shown in Table 2 below:

[0042] Table 2

[0043]

[0044] 2. Nickel recovery

[0045] (1) Take 30 mL of valuable metal leaching solution and weigh n(DMG:Ni 2+ ) is 2:1 butanedione oxime 0.75g, that is, when the molar ratio of butanedione oxime to nickel ion is 2:1, the mass content of butanedione oxime is 0.75g.

[0046] (2) Add diacetyl oxime to the leaching solution and react at a temperature of 50°C and a pH of 5 for 50 minutes.

[0047] (3) The solution of step (2) is filtered to obtain a filtrate 1 and a filter residue. The contents of Li, Ni, Co and Mn in the filtrate 1 are measured to obtain a precipitation rate, as shown in Table 3 below.

[0048] The filter residue was repeatedly rinsed, dried at 60℃ for 24h, and then ground for phase analysis. Figure 1 As shown, the precipitated product is nickel diacetate. After the nickel precipitate is digested and tested by ICP (as shown in Table 4), the Ni content is 20.28%, and the impurity contents of Li, Co and Mn are relatively low. The purity of the Ni precipitate is calculated to be 99.83%.

[0049] Table 3

[0050]

[0051] Table 4 Contents of Ni, Co, Mn and Li in nickel diacetate products

[0052]

[0053] 3. Recycling cobalt

[0054] (1) Take 30 mL of filtrate 1 and 0.6 mL of an ammonium sulfide solution having an ammonium sulfide addition amount (V / V) of 2%, wherein the ammonium sulfide is an undiluted analytically pure ammonium sulfide solution.

[0055] (2) Add the ammonium sulfide solution to the filtrate 1 and react at 30°C and pH 4 for 30 minutes.

[0056] (3) The solution of step (2) is filtered to obtain filtrate 2 and filter residue. The contents of Li, Co and Mn in filtrate 2 are measured to obtain the precipitation rate, as shown in Table 5 below.

[0057] The filter residue was repeatedly rinsed, dried at 60℃ for 24h, and then ground for phase analysis. Figure 2 As shown, the precipitated product is amorphous cobalt sulfide. After digestion, the cobalt precipitated product was tested by ICP (as shown in Table 6), and the Co content was 63.91%, and the impurity contents of Li, Ni and Mn were relatively low. The purity of the Co precipitated product was calculated to be 98.68%.

[0058] Table 5

[0059]

[0060] Table 6 Contents of Ni, Co, Mn and Li in amorphous cobalt sulfide products

[0061]

[0062] 4. Recycling manganese

[0063] (1) Take 30 mL of filtrate 2 and add 1.05 mL of 3.5% ammonium sulfide solution (V / V). The ammonium sulfide is an undiluted analytically pure ammonium sulfide solution.

[0064] (2) adding the ammonium sulfide solution to the filtrate 2 in step (1) and reacting at a temperature of 30° C. and a pH of 9 for 30 min.

[0065] (3) The solution of step (2) was filtered to obtain filtrate 3 and filter residue. The contents of Li and Mn in filtrate 3 were measured to obtain the precipitation rate, as shown in Table 7 below.

[0066] The filter residue was repeatedly rinsed, dried at 60℃ for 24h, and then ground for phase analysis. Figure 3 As shown, the precipitation product is manganese sulfide. After digestion, the manganese precipitation product was tested by ICP (as shown in Table 8), and the Mn content was 62.78%, the Li and Co impurity contents were low, and no Ni impurity was detected. The purity of the Mn precipitation product was calculated to be 99.43%.

[0067] Table 7

[0068]

[0069] Table 8 Contents of Ni, Co, Mn and Li in manganese sulfide products

[0070]

[0071] 5. Recycling lithium

[0072] (1) Take 30 mL of filtrate 3 and weigh the amount of phosphate added as n(PO 4 3- :Li + )=0.6:1 trisodium phosphate 0.59g.

[0073] (2) Add the ammonium sulfide solution to the filtrate 3 and react at 90°C and pH 8 for 60 minutes.

[0074] (3) The solution of step (2) was filtered to obtain filtrate 4 and filter residue. The Li content in filtrate 4 was measured to obtain the precipitation rate, as shown in Table 9 below.

[0075] The filter residue was repeatedly rinsed, dried at 60℃ for 24h, and then ground for phase analysis. Figure 4 As shown, the precipitated product is trilithium phosphate. After digestion, the lithium precipitated product was tested by ICP (as shown in Table 10), and the Li content was 17.78%, the Mn impurity content was low, and no Co and Ni impurities were detected. The purity of the Li precipitated product was calculated to be 98.87%.

[0076] Table 9

[0077]

[0078] Table 10 Contents of Ni, Co, Mn and Li in trilithium phosphate products

[0079]

[0080] Example 2

[0081] Using the raw materials obtained above to carry out leaching reaction experiments, a method for recovering valuable metals Li, Ni, Co and Mn in the positive electrode materials of waste ternary lithium-ion batteries comprises the following steps:

[0082] 1. Preparation of leachate

[0083] (1) Prepare a mixed solution of methanesulfonic acid and ascorbic acid of required concentration, and take 0.4 g of pretreated lithium-ion battery positive electrode material.

[0084] (2) Add 20 mL of mixed acid (1.1 mol / L methanesulfonic acid and 0.02 mol / L ascorbic acid) to the positive electrode material and react at a temperature of 80°C and a rotation speed of 200 r / min for 10 min.

[0085] (3) Filter the leaching solution to obtain a valuable metal leaching solution.

[0086] 2. Nickel recovery

[0087] (1) Take 30 mL of valuable metal leaching solution and weigh n(DMG:Ni 2+ ) is 1:5, that is, when the molar ratio of dimethylglyoxime to nickel ion is 1:5, the mass content of dimethylglyoxime is 0.75g.

[0088] (2) Add diacetyl oxime to the leaching solution and react at 80°C and pH 7 for 90 minutes.

[0089] (3) Filter the solution in step (2) to obtain filtrate 1 and filter residue. The filter residue is repeatedly rinsed, dried at 60° C. for 24 h, and then ground to obtain a precipitated product of nickel diacetate.

[0090] 3. Recycling cobalt

[0091] (1) Take 30 mL of filtrate 1 and 0.6 mL of an ammonium sulfide solution having an ammonium sulfide addition amount (V / V) of 12%. The ammonium sulfide is an undiluted analytically pure ammonium sulfide solution.

[0092] (2) Add the ammonium sulfide solution to the filtrate 1 and react at 80°C and pH 6 for 50 minutes.

[0093] (3) The solution of step (2) is filtered to obtain filtrate 2 and filter residue. The filter residue is repeatedly rinsed, dried at 60° C. for 24 h, and then ground to obtain a precipitated product of amorphous cobalt sulfide.

[0094] 4. Recycling manganese

[0095] (1) Take 30 mL of filtrate 2 and add 1.5 mL of 1% ammonium sulfide solution (V / V). The ammonium sulfide is an undiluted analytically pure ammonium sulfide solution.

[0096] (2) adding the ammonium sulfide solution to the filtrate 2 in step (1) and reacting at a temperature of 50° C. and a pH of 5 for 30 minutes.

[0097] (3) The solution of step (2) is filtered to obtain filtrate 3 and filter residue. The filter residue is repeatedly rinsed, dried at 60° C. for 24 h, and then ground to obtain a precipitated product of manganese sulfide.

[0098] 5. Recycling lithium

[0099] (1) Take 30 mL of filtrate 3 and weigh the amount of phosphate added as n(PO 4 3- :Li + )=0.2:1 trisodium phosphate 0.59g.

[0100] (2) Add the ammonium sulfide solution to the filtrate 3 and react at 95°C and pH 5 for 60 minutes.

[0101] (3) Filter the solution in step (2) to obtain filtrate 4 and filter residue. The filter residue is repeatedly rinsed, dried at 60° C. for 24 h, and then ground to obtain a precipitated product of trilithium phosphate.

[0102] Example 3

[0103] Using the raw materials obtained above to carry out leaching reaction experiments, a method for recovering valuable metals Li, Ni, Co and Mn in the positive electrode materials of waste ternary lithium-ion batteries comprises the following steps:

[0104] 1. Preparation of leachate

[0105] (1) Prepare a mixed solution of methanesulfonic acid and ascorbic acid of required concentration, and take 0.4 g of pretreated lithium-ion battery positive electrode material.

[0106] (2) Add 20 mL of mixed acid (0.2 mol / L methanesulfonic acid and 0.16 mol / L ascorbic acid) to the positive electrode material and react at a temperature of 30°C and a rotation speed of 200 r / min for 10 min.

[0107] (3) Filter the leaching solution to obtain a valuable metal leaching solution.

[0108] 2. Nickel recovery

[0109] (1) Take 30 mL of valuable metal leaching solution and weigh n(DMG:Ni 2+ ) is 1:1 dimethylglyoxime 0.75g. That is, when the molar ratio of dimethylglyoxime to nickel ion is 1:1, the mass content of dimethylglyoxime is 0.75g.

[0110] (2) Add diacetyl oxime to the leaching solution and react at a temperature of 30°C and a pH of 2 for 50 minutes.

[0111] (3) Filter the solution in step (2) to obtain filtrate 1 and filter residue. The filter residue is repeatedly rinsed, dried at 60° C. for 24 h, and then ground to obtain a precipitated product of nickel diacetate.

[0112] 3. Recycling cobalt

[0113] (1) Take 30 mL of filtrate 1 and 1 mL of ammonium sulfide solution with an ammonium sulfide addition amount (V / V) of 0.5%. The ammonium sulfide is an undiluted analytically pure ammonium sulfide solution.

[0114] (2) Add the ammonium sulfide solution to the filtrate 1 and react at 50°C and pH 1 for 30 minutes.

[0115] (3) The solution of step (2) is filtered to obtain filtrate 2 and filter residue. The filter residue is repeatedly rinsed, dried at 60° C. for 24 h, and then ground to obtain a precipitated product of amorphous cobalt sulfide.

[0116] 4. Recycling manganese

[0117] (1) Take 30 mL of filtrate 2 and add 1.05 mL of 5% ammonium sulfide solution (V / V). The ammonium sulfide is an undiluted analytical grade ammonium sulfide solution.

[0118] (2) adding the ammonium sulfide solution to the filtrate 2 in step (1) and reacting at a temperature of 40° C. and a pH of 11 for 30 minutes.

[0119] (3) The solution of step (2) is filtered to obtain filtrate 3 and filter residue. The filter residue is repeatedly rinsed, dried at 60° C. for 24 h, and then ground to obtain a precipitated product of manganese sulfide.

[0120] 5. Recycling lithium

[0121] (1) Take 30 mL of filtrate 3 and weigh the amount of phosphate added as n(PO 4 3- :Li + )=1:1 trisodium phosphate 0.62g.

[0122] (2) Add the ammonium sulfide solution to the filtrate 3 and react at 60°C and pH 10 for 60 minutes.

[0123] (3) Filter the solution in step (2) to obtain filtrate 4 and filter residue. The filter residue is repeatedly rinsed, dried at 60° C. for 24 h, and then ground to obtain a precipitated product of trilithium phosphate.

[0124] The foregoing description of specific exemplary embodiments of the present invention is for the purpose of illustration and demonstration. These descriptions are not intended to limit the present invention to the precise form disclosed, and it is clear that many changes and variations can be made based on the above teachings. The purpose of selecting and describing the exemplary embodiments is to explain the specific principles of the present invention and its practical application, so that those skilled in the art can realize and utilize various different exemplary embodiments of the present invention and various different selections and changes. The scope of the present invention is intended to be limited by the claims and their equivalents.

Claims

1. A method for recovering valuable metals Li, Ni, Co and Mn from waste ternary lithium-ion battery positive electrode materials, characterized in that: The following steps are involved: (1) obtaining waste ternary lithium-ion battery positive electrode materials, roasting, then adding methanesulfonic acid and ascorbic acid to mix and react, filtering, and obtaining a valuable metal leaching solution; (2) Add diacetyl oxime to the leaching solution of step (1) to precipitate Ni 2+ After the reaction is complete, the filtrate 1 and the filter residue are obtained, and the filter residue is washed several times to obtain nickel diacetate; (3) Adjust the pH of filtrate 1 and precipitate Co using ammonium sulfide 2+ After the reaction is complete, the mixture is filtered to obtain filtrate 2 and filter residue, and the filter residue is cobalt sulfide after multiple washings; (4) Adjust the pH of filtrate 2 to precipitate Mn 2+ After the reaction is complete, the mixture is filtered to obtain filtrate 3 and filter residue, which is manganese sulfide after being washed several times; (5) Add phosphate to filtrate 3 to precipitate Li + After the reaction is complete, filter to obtain filtrate 4 and filter residue, which is trilithium phosphate after multiple washings.

2. The method for recovering valuable metals Li, Ni, Co and Mn in the positive electrode material of waste ternary lithium-ion batteries according to claim 1, characterized in that: The calcination in step (1) is performed at 450-600° C. for 1-10 hours.

3. The method for recovering valuable metals Li, Ni, Co and Mn in the positive electrode material of waste ternary lithium-ion batteries according to claim 1, characterized in that: In step (1), the concentration of methanesulfonic acid is 0.2-1.1 mol / L, the concentration of ascorbic acid is 0.02-0.16 mol / L, the solid-liquid ratio of the reaction system is 10-50 g / L, and the leaching reaction is carried out at 30-80° C. for 2-30 min.

4. The method for recovering valuable metals Li, Ni, Co and Mn from the positive electrode material of waste ternary lithium-ion batteries according to claim 1, characterized in that: Step (2) Reaction of diacetyl oxime with Ni 2+ The molar ratio is 1:2-5:1, the pH of the complex precipitation reaction is 2-7, and the reaction is carried out at 30-80°C for 5-90 minutes.

5. The method for recovering valuable metals Li, Ni, Co and Mn in the positive electrode material of waste ternary lithium-ion batteries according to claim 1, characterized in that: The ammonium sulfide in step (3) is an undiluted analytically pure ammonium sulfide solution, the volume percentage V / V of the undiluted ammonium sulfide added is 0.5-12%, the pH of the precipitation reaction is 1-6, and the reaction is carried out at 30-80° C. for 5-50 minutes.

6. The method for recovering valuable metals Li, Ni, Co and Mn in the positive electrode material of waste ternary lithium-ion batteries according to claim 1, characterized in that: Step (4) adjusting the pH of the filtrate 2 and precipitating Mn using ammonium sulfide 2+ The ammonium sulfide is an undiluted analytical pure ammonium sulfide solution, the volume percentage V / V of the undiluted ammonium sulfide added is 0-5%, the pH of the precipitation reaction is 5-11, and the reaction is carried out at 30-80°C for 5-50 minutes.

7. The method for recovering valuable metals Li, Ni, Co and Mn from the positive electrode materials of waste ternary lithium-ion batteries according to claim 1, characterized in that: In step (5), phosphate and Li 2+ The molar ratio is 0.2:1-1.2:1, the pH of the precipitation reaction is 5-10, and the reaction is carried out at 60-95°C for 30-90 minutes.

8. The method for recovering valuable metals Li, Ni, Co and Mn in the positive electrode material of waste ternary lithium-ion batteries according to claim 1, characterized in that: The phosphate in step (5) is one or more of sodium dihydrogen phosphate, potassium dihydrogen phosphate, disodium hydrogen phosphate, diammonium hydrogen phosphate, trisodium phosphate, sodium pyrophosphate, calcium pyrophosphate, sodium tripolyphosphate, sodium hexametaphosphate, sodium metaphosphate or sodium polyphosphate; preferably trisodium phosphate.

9. The method for recovering valuable metals Li, Ni, Co and Mn in the positive electrode material of waste ternary lithium-ion batteries according to claim 1, characterized in that: After the filter residues in step (3), step (4) and step (5) are washed, they are dried at 50-70° C. for 10-48 hours.

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