Method for separating and recycling metal elements in waste ternary lithium ion battery leachate

Abstract

The invention relates to the technical field of battery recovery, in particular to a method for separating and recovering metal elements in waste ternary lithium ion battery leachate, which comprises the following steps: A) mixing an extracting agent 2-n-hexyldecanoic acid with a diluent to obtain an extracting solvent; b) mixing the extracting solvent with a saponifying agent to obtain a saponified extracting solvent; c1) mixing the waste ternary lithium ion battery leachate with the saponified extraction solvent, and carrying out single-stage extraction to obtain a raffinate water phase and a loaded organic phase; and D1) mixing the loaded organic phase with a back extraction agent, and carrying out back extraction to obtain a back extraction solution and a blank organic phase. According to the invention, the problems of complex recovery process and difficult separation of calcium and magnesium in the nickel-cobalt-manganese co-extraction process in the prior art are solved, and the recovery of nickel, cobalt and manganese can be realized through one-step selective co-extraction process; the technological process is short and the metal recovery rate is high.

Description

Technical Field

[0001] The present invention relates to the technical field of battery recycling, and particularly relates to a method for separating and recycling metal elements in the leaching solution of waste ternary lithium-ion batteries. Background Art

[0002] Lithium-ion batteries are widely used in the fields of electric vehicles and electronic devices due to their superior safety performance and excellent electrochemical characteristics. In recent years, under the influence of multiple factors such as energy, environment, and technology, the new energy vehicle industry has shown explosive development, directly driving the rapid growth of the output and installation scale of lithium-ion power batteries. However, due to the rapid growth of electric vehicle sales, the number of waste lithium-ion batteries has also increased. These waste lithium batteries contain toxic and corrosive electrolytes and need to be properly disposed of, otherwise they will have a negative impact on the environment and human health. In addition, waste lithium-ion batteries are also regarded as important secondary mineral resources because they contain much more valuable metals than natural ores, such as 5wt% - 10wt% nickel, 20wt% cobalt, and 5wt% - 7wt% lithium. Therefore, recycling waste lithium-ion batteries has significant environmental and economic benefits.

[0003] Patent application document CN115141933A provides a method for purifying the leaching solution of ternary lithium batteries. First, impurities such as calcium and magnesium are removed by the fluoride precipitation method, and then nickel-cobalt-manganese products are recovered by one-step extraction. However, the calcium fluoride and magnesium fluoride precipitates generated by the fluoride precipitation method are easy to form colloids, difficult to filter and separate, and prone to entrainment loss of valuable metals.

[0004] Patent application document CN112442596A provides a method for separating and recycling nickel, cobalt, and manganese in the intermediate liquid of batteries using a carboxylic acid extractant. Nickel, cobalt, and manganese products are respectively recovered by multi-step extraction to achieve separation from calcium and magnesium impurities. However, using multiple extractants makes the process flow complex, the production cost high, the operation unstable, and the existing extraction system has a low separation coefficient of nickel, cobalt, and manganese from calcium and magnesium, and the separation of calcium and magnesium is not complete.

[0005] Therefore, a new process for recycling different metal elements in battery liquid is needed, which can effectively reduce the loss of valuable metals while taking into account excellent impurity removal effects. Summary of the Invention

[0006] In view of this, the technical problem to be solved by the present invention is to provide a method for separating and recycling metal elements in the leaching solution of waste ternary lithium-ion batteries, which has a short process flow and a high metal recovery rate.

[0007] The present invention provides a method for separating and recycling metal elements in the leaching solution of waste ternary lithium-ion batteries, comprising the following steps:

[0008] A) Mix the extractant 2-n-hexyldecanoic acid with a diluent to obtain an extraction solvent;

[0009] B) Mix the extraction solvent with a saponifying agent to obtain a saponified extraction solvent;

[0010] C1) Mix the leaching solution of waste ternary lithium-ion battery with the saponified extraction solvent for single-stage extraction to obtain a raffinate aqueous phase and a loaded organic phase;

[0011] D1) Mix the loaded organic phase with a stripping agent for stripping to obtain a stripping solution and a blank organic phase.

[0012] The present invention also provides a method for separating and recovering metal elements from the leaching solution of waste ternary lithium-ion batteries, including the following steps:

[0013] A) Mix the extractant 2-n-hexyldecanoic acid with a diluent to obtain an extraction solvent;

[0014] B) Mix the extraction solvent with a saponifying agent to obtain a saponified extraction solvent;

[0015] C2) Mix the leaching solution of waste ternary lithium-ion battery, the saponified extraction solvent and a detergent for 6-10 stage countercurrent extraction and 7-10 stage countercurrent washing to obtain a washed organic phase;

[0016] D2) Mix the washed organic phase with a stripping agent for 3-5 stage countercurrent stripping to obtain a stripping solution and a blank organic phase.

[0017] Preferably, in step A), the diluent is selected from GV-18A, kerosene or solvent oil.

[0018] Preferably, in step A), in the extraction solvent, the volume concentration of the extractant is 5%-35%.

[0019] Preferably, in step B), the saponifying agent is selected from sodium hydroxide solution, ammonia water, sodium carbonate solution or ammonium carbonate solution.

[0020] Preferably, in step B), the saponification degree of the saponified extraction solvent is 10%-40%.

[0021] Preferably, the metal elements contained in the leaching solution of the waste ternary lithium-ion battery include nickel, cobalt, manganese, lithium, calcium and magnesium.

[0022] Preferably, the temperature of the extraction is 20-30 °C and the time is 10-20 min;

[0023] The extraction is carried out under the condition of shaking.

[0024] Preferably, the stripping agent is sulfuric acid with a concentration of 0.5 - 2.5 mol / L.

[0025] Preferably, the temperature of the stripping is 20 - 30 °C and the time is 10 - 20 min;

[0026] The stripping is carried out under the condition of shaking.

[0027] The present invention provides a method for separating and recovering metal elements from the leaching solution of waste ternary lithium-ion batteries, comprising the following steps: A) Mixing an extractant 2-n-hexyldecanoic acid with a diluent to obtain an extraction solvent; B) Mixing the extraction solvent with a saponifying agent to obtain a saponified extraction solvent; C1) Mixing the leaching solution of waste ternary lithium-ion batteries with the saponified extraction solvent for single-stage extraction to obtain a raffinate aqueous phase and a loaded organic phase; D1) Mixing the loaded organic phase with a stripping agent for stripping to obtain a stripping solution and a blank organic phase. The present invention also provides a method for separating and recovering metal elements from the leaching solution of waste ternary lithium-ion batteries, comprising the following steps: A) Mixing an extractant 2-n-hexyldecanoic acid with a diluent to obtain an extraction solvent; B) Mixing the extraction solvent with a saponifying agent to obtain a saponified extraction solvent; C2) Mixing the leaching solution of waste ternary lithium-ion batteries, the saponified extraction solvent and a detergent for 6 - 10 stages of countercurrent extraction and 7 - 10 stages of countercurrent washing to obtain a washed organic phase; D2) Mixing the washed organic phase with a stripping agent for 3 - 5 stages of countercurrent stripping to obtain a stripping solution and a blank organic phase. The present invention solves the problems of complex recovery processes in the prior art and the difficulty in separating the co-extraction process of nickel, cobalt and manganese from calcium and magnesium. The recovery of nickel, cobalt and manganese can be achieved through a one-step selective co-extraction process; the process flow is short and the metal recovery rate is high. Detailed Embodiments

[0028] The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0029] The present invention provides a method for separating and recovering metal elements from the leaching solution of waste ternary lithium-ion batteries, comprising the following steps:

[0030] A) Mixing an extractant 2-n-hexyldecanoic acid with a diluent to obtain an extraction solvent;

[0031] B) Mixing the extraction solvent with a saponifying agent to obtain a saponified extraction solvent;

[0032] C1) Mix the leaching solution of waste ternary lithium-ion battery with the saponified extraction solvent for single-stage extraction to obtain the raffinate aqueous phase and the loaded organic phase;

[0033] D1) Mix the loaded organic phase with the stripping agent for stripping to obtain the stripping solution and the blank organic phase.

[0034] The present invention also provides a method for separating and recovering metal elements from the leaching solution of waste ternary lithium-ion battery, comprising the following steps:

[0035] A) Mix the extractant 2-n-hexyldecanoic acid with a diluent to obtain an extraction solvent;

[0036] B) Mix the extraction solvent with a saponifying agent to obtain a saponified extraction solvent;

[0037] C2) Mix the leaching solution of waste ternary lithium-ion battery, the saponified extraction solvent and a detergent for 6-10 stage countercurrent extraction and 7-10 stage countercurrent washing to obtain a washed organic phase;

[0038] D2) Mix the washed organic phase with the stripping agent for 3-5 stage countercurrent stripping to obtain the stripping solution and the blank organic phase.

[0039] Regarding step A):

[0040] Mix the extractant 2-n-hexyldecanoic acid (DY319) with a diluent to obtain an extraction solvent.

[0041] In some embodiments of the present invention, the diluent is selected from GV-18A, kerosene or solvent oil.

[0042] In some embodiments of the present invention, in the extraction solvent, the volume concentration of the extractant is 5%-35%, such as 5%, 15%, 25%, 30%, 35%.

[0043] Regarding step B):

[0044] Mix the extraction solvent with a saponifying agent to obtain a saponified extraction solvent.

[0045] In some embodiments of the present invention, the saponifying agent is selected from sodium hydroxide solution, ammonia water, sodium carbonate solution or ammonium carbonate solution. The concentration of the sodium hydroxide solution is 5-7 mol / L, such as 6 mol / L. The solvent of the sodium hydroxide solution is water.

[0046] In some embodiments of the present invention, the saponification degree of the saponified extraction solvent is 10%-40%; such as 15%, 30%, 35%, 40%.

[0047] There are two methods for treating the leaching solution of waste ternary lithium-ion battery:

[0048] The first treatment method is step C1):

[0049] Mix the leaching solution of waste ternary lithium-ion battery with the saponified extraction solvent, and perform single-stage extraction to obtain the raffinate aqueous phase and the loaded organic phase.

[0050] In some embodiments of the present invention, the metal elements contained in the leaching solution of waste ternary lithium-ion battery include nickel, cobalt, manganese, lithium, calcium, and magnesium.

[0051] In some embodiments of the present invention, the mass ratio of the leaching solution of waste ternary lithium-ion battery to the saponified extraction solvent is 1-5:1-10, such as 1:5, 1:4.

[0052] In some embodiments of the present invention, the temperature of the single-stage extraction is 20-30°C, such as 25°C; the time is 10-20 min, such as 15 min. The single-stage extraction is carried out under the condition of shaking.

[0053] After single-stage extraction, nickel, cobalt, and manganese are extracted into the organic phase, realizing the separation from lithium, calcium, and magnesium.

[0054] After the single-stage extraction, it further includes: separating the raffinate aqueous phase and the loaded organic phase.

[0055] The second treatment method is step C2):

[0056] Mix the leaching solution of waste ternary lithium-ion battery, the saponified extraction solvent, and the detergent, and perform 6-10 stages of countercurrent extraction and 7-10 stages of countercurrent washing to obtain the washed organic phase.

[0057] In some embodiments of the present invention, the detergent used for washing is sulfuric acid or hydrochloric acid; the concentration is 0.2-0.5 mol / L, such as 0.5 mol / L.

[0058] In some embodiments of the present invention, the volume ratio of the leaching solution of waste ternary lithium-ion battery, the saponified extraction solvent, and the detergent is 1-5:1-10:1-5, such as 1.5:10:1.5.

[0059] In some embodiments of the present invention, the temperature of the countercurrent extraction is 20-30°C, such as 25°C. The cascade extraction is carried out under the condition of shaking.

[0060] In some embodiments of the present invention, the number of stages of the countercurrent extraction is 6.

[0061] In some embodiments of the present invention, the number of stages of the countercurrent washing is 7.

[0062] After the cascade extraction and washing, it further includes: separating the washing liquid and the washing organic phase.

[0063] Regarding step D1):

[0064] After obtaining the loaded organic phase, mix the loaded organic phase with the stripping agent for stripping to obtain a stripping solution and a blank organic phase.

[0065] In some embodiments of the present invention, the stripping agent is sulfuric acid; the concentration is 0.5 - 2.5 mol / L, such as 0.5 mol / L.

[0066] In some embodiments of the present invention, the mass ratio of the loaded organic phase to the stripping agent is 1 - 20:1.

[0067] In some embodiments of the present invention, the temperature of the stripping is 20 - 30 °C, such as 25 °C; the time is 10 - 20 min, such as 15 min. The stripping is carried out under the condition of shaking.

[0068] Regarding step D2):

[0069] After obtaining the washing organic phase, mix the washing organic phase with the stripping agent for 3 - 5 - stage counter - current stripping to obtain a stripping solution and a blank organic phase.

[0070] In some embodiments of the present invention, the stripping agent is sulfuric acid; the concentration is 0.5 - 2.5 mol / L, such as 0.5 mol / L, 2 mol / L.

[0071] In some embodiments of the present invention, the mass ratio of the washing organic phase to the stripping agent is 1 - 20:1, such as 1:1, 20:1.

[0072] In some embodiments of the present invention, the temperature of the counter - current stripping is 20 - 30 °C, such as 25 °C; the time is 10 - 20 min, such as 15 min. The counter - current stripping is carried out under the condition of shaking.

[0073] In some embodiments of the present invention, the number of stages of the counter - current stripping is 5.

[0074] In order to strip nickel, cobalt, and manganese loaded in the organic phase, it is necessary to mix the loaded organic phase or the washing organic phase with the stripping agent according to a certain phase ratio, and finally obtain a stripping solution containing nickel, cobalt, and manganese and a blank organic phase.

[0075] The present invention has no special restrictions on the sources of the raw materials used above, and they can be commercially available generally.

[0076] The present invention uses a saponified extractant to treat nickel, cobalt, and manganese in the leaching solution of waste batteries. Through a single-step extraction operation, valuable metals nickel, cobalt, and manganese can be separated from lithium, calcium, and magnesium.

[0077] The extractant used in the present invention has excellent selectivity for nickel, cobalt, and manganese. Through 13-stage cascade extraction, 99.9% of nickel, cobalt, and manganese can be recovered, avoiding the entrainment loss of valuable metals during the removal of calcium and magnesium.

[0078] The process flow of the present invention is short and the operation is simple, reducing the separation cost of separately recovering nickel, cobalt, and manganese, as well as the extraction and purification cost of impurity metal ions.

[0079] To further illustrate the present invention, the following is a detailed description of a method for separating and recovering metal elements in the leaching solution of waste ternary lithium-ion batteries provided by the present invention in conjunction with embodiments, but it should not be construed as a limitation on the protection scope of the present invention.

[0080] Example 1

[0081] 1. Preparation of extraction solvent:

[0082] Mix the extractant 2-n-hexyldecanoic acid (DY319) with the diluent GV-18A to obtain an extraction solvent; in the extraction solvent, the volume concentration of the extractant is 35%.

[0083] 2. Saponification of extraction solvent:

[0084] Use 6 mol / L sodium hydroxide aqueous solution to saponify the extraction solvent, and the saponification degree of the saponified extraction solvent is 30%.

[0085] 3. Extraction:

[0086] Mix the leaching solution of waste ternary lithium-ion batteries with the saponified extraction solvent according to a mass ratio of 1:5, and perform single-stage extraction for 15 min under the conditions of 25°C and shaking to obtain a raffinate aqueous phase and a loaded organic phase.

[0087] 4. Stripping:

[0088] Mix the loaded organic phase with a stripping agent (0.5 mol / L sulfuric acid) according to a mass ratio of 1:1, and perform stripping for 15 min under the conditions of 25°C and shaking to obtain a stripping solution and a blank organic phase.

[0089] Separate the stripping solution and the blank organic phase.

[0090] Analyze the content of metal elements in the leaching solution of waste ternary lithium-ion batteries and the content of metal elements in the raffinate aqueous phase, and calculate the extraction rate E of each metal element through calculation, specifically calculated according to formula (1):

[0091] E = (C1 - C0) / C1, Equation (1);

[0092] In Equation (1), E: extraction rate of metal elements;

[0093] C1: content of metal elements in the leaching solution of waste ternary lithium-ion batteries, mg / L;

[0094] C0: content of metal elements in the raffinate aqueous phase, mg / L.

[0095] The results are shown in Table 1.

[0096] Table 1 Extraction rate of metal elements in the leaching solution of waste ternary lithium-ion batteries

[0097]

[0098] Referring to Table 1, when extracting with CA12 alone, the system preferentially extracts calcium, and the extraction rate of calcium reaches 56.01%. Nickel, cobalt, and manganese cannot be separated from calcium. When extracting with DY319 alone, the system preferentially extracts nickel, cobalt, and manganese, and the extraction rates of nickel, cobalt, and manganese all exceed 75%. At this time, the extraction rates of calcium and magnesium are 0, and that of lithium is only 12.69%. This shows that the DY319 extractant can co-extract and recover nickel, cobalt, and manganese from the battery leaching solution and achieve efficient separation of nickel, cobalt, and manganese from the impurity elements calcium, magnesium, and lithium.

[0099] Example 2

[0100] 1. Preparation of extraction solvent:

[0101] Mix the extractant 2-n-hexyldecanoic acid (DY319) with the diluent GV-18A to obtain the extraction solvent. In the extraction solvent, the volume concentration of the extractant is 35%. Set 8 groups of extraction solvents in this way.

[0102] 2. Saponification of extraction solvent:

[0103] Use 6 mol / L sodium hydroxide aqueous solution to saponify the above 8 groups of extraction solvents respectively. The saponification degrees of the saponified extraction solvents are 5%, 15%, 30%, 35%, 40%, 45%, 50%, and 60% respectively.

[0104] 3. Extraction:

[0105] Mix 8 groups of the same leaching solutions of waste ternary lithium-ion batteries with the above 8 groups of saponified extraction solvents according to a mass ratio of 1:4, and perform single-stage extraction for 15 min under the conditions of 25°C and shaking to obtain 8 groups of raffinate aqueous phases and loaded organic phases.

[0106] 4. Stripping:

[0107] Mix the 8 groups of loaded organic phases with the stripping agent (0.5 mol / L sulfuric acid) at a mass ratio of 1:1, and perform stripping for 15 min under the conditions of 25°C and shaking to obtain 8 groups of stripping solutions and blank organic phases.

[0108] Separate the stripping solution and the blank organic phase.

[0109] Analyze the extraction rate of metal elements in the raffinate aqueous phase according to the same method as in Example 1, and the results are shown in Table 2.

[0110] Table 2 Extraction rates of metal elements in the leachate of waste ternary lithium-ion batteries

[0111]

[0112] Table 2 studied the effect of different saponification degrees on the metal extraction rate. It can be seen from Table 2 that as the saponification degree of DY319 increases, the improvement of the separation effect is no longer obvious. Therefore, choosing an appropriate saponification degree is beneficial to achieve the efficient separation of nickel, cobalt, manganese and impurity calcium, magnesium and lithium in the battery leachate.

[0113] Example 3

[0114] 1. Prepare the extraction solvent:

[0115] Mix the extractant 2-n-hexyldecanoic acid (DY319) with the diluent GV-18A to obtain the extraction solvent; prepare 7 groups of extraction solvents, and the volume concentrations of the corresponding extractants are 5%, 15%, 25%, 30%, 35%, 40%, and 45% respectively.

[0116] 2. Saponify the extraction solvent:

[0117] Use 6 mol / L sodium hydroxide aqueous solution to saponify the above 7 groups of extraction solvents respectively, and the saponification degree of the saponified extraction solvents is 35%.

[0118] 3. Extraction:

[0119] Mix 7 groups of the same leachate of waste ternary lithium-ion batteries with the above 7 groups of saponified extraction solvents at a mass ratio of 1:4, and perform single-stage extraction for 15 min under the conditions of 25°C and shaking to obtain 8 groups of raffinate aqueous phases and loaded organic phases.

[0120] 4. Stripping:

[0121] Mix the 7 groups of loaded organic phases with the stripping agent (0.5 mol / L sulfuric acid) at a mass ratio of 1:1, and perform stripping for 15 min under the conditions of 25°C and shaking to obtain 7 groups of stripping solutions and blank organic phases.

[0122] Separate the stripping solution and the blank organic phase.

[0123] The extraction rate of metal elements in the raffinate aqueous phase was analyzed in the same manner as in Example 1. The results are shown in Table 3.

[0124] Table 3 Extraction rate of metal elements in the leachate of waste ternary lithium-ion batteries

[0125]

[0126] Table 3 studies the effects of different volume concentrations of extractants on metal extraction rates. It can be seen from Table 3 that as the volume concentration of the extractant increases, the extraction rates of various metal ions increase accordingly. At a volume concentration of 40%, the extraction rates of lithium, calcium, and magnesium are relatively high, and the separation effect is not obvious. Therefore, selecting a volume concentration of 5% to 35% is conducive to achieving efficient separation of nickel, cobalt, and manganese from impurities calcium, magnesium, and lithium in the leachate of ternary lithium-ion batteries.

[0127] Example 4

[0128] 1. Preparation of extraction solvent:

[0129] The extractant 2-n-hexyldecanoic acid (DY319) was mixed with the diluent GV-18A to obtain an extraction solvent; the volume concentration of the extractant in the extraction solvent was 35%.

[0130] 2. Saponification extraction solvent:

[0131] 250 mL of the extraction solvent was taken and saponified using a 6 mol / L sodium hydroxide aqueous solution. The saponification degree of the extraction solvent after saponification was 35%.

[0132] 3. Extraction and washing:

[0133] The waste ternary lithium-ion battery leachate, the saponified extraction solvent and the detergent (0.5 mol / L sulfuric acid) are mixed in a volume ratio of 1.5:10:1.5, and countercurrent extraction and countercurrent washing are carried out at 25°C and under shaking conditions. The countercurrent extraction stage is 6 extraction sections, and the countercurrent washing stage is 7 washing sections to obtain a raffinate aqueous phase, a washing liquid and a washing organic phase.

[0134] 4. Stripping:

[0135] The washed organic phase was mixed with a stripping agent (2 mol / L sulfuric acid) in a mass ratio of 20:1, and countercurrent stripping was performed at 25° C. with shaking for 15 min. The countercurrent stripping stage was 5, to obtain a stripping solution and a blank organic phase.

[0136] The stripping liquid and the blank organic phase were separated. The metal element content in the liquid discharged from the outlet of the aqueous phase (the raffinate aqueous phase obtained in step 3) and the outlet of the organic phase (the stripping liquid obtained in step 4) was analyzed. The results are shown in Table 4.

[0137] Content of metal elements in the liquid discharged from the aqueous phase outlet and the organic phase outlet in Table 4

[0138]

[0139]

[0140] As can be seen from Table 4, the contents of nickel, cobalt, and manganese in the outlet of the obtained aqueous phase (the raffinate aqueous phase obtained in Step 3) are low, and the contents of Li, Ca, and Mg in the outlet of the organic phase (the stripping solution obtained in Step 4) are low, indicating obvious impurity removal effect. Through calculation, it can be known that the recovery rate of nickel, cobalt, and manganese at the organic phase outlet exceeds 99%, and the purity exceeds 99.9%; the total concentration of nickel, cobalt, and manganese in the stripping solution is >90 g / L, and the contents of aluminum, iron, copper, cadmium, chromium, and lead are all less than 0.5 mg / L, and all indicators meet the national standard of nickel cobalt manganese sulfate solution for batteries.

[0141] The description of the above embodiments is only used to help understand the method and its core idea of the present invention. Various modifications to these embodiments will be obvious to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for separating and recovering metal elements from the leaching solution of waste ternary lithium-ion batteries, comprising the following steps: A) Mixing an extractant 2-n-hexyldecanoic acid with a diluent to obtain an extraction solvent; B) Mixing the extraction solvent with a saponifying agent to obtain a saponified extraction solvent; C1) Mixing the leaching solution of waste ternary lithium-ion batteries with the saponified extraction solvent for single-stage extraction to obtain a raffinate aqueous phase and a loaded organic phase; D1) Mixing the loaded organic phase with a stripping agent for stripping to obtain a stripping solution and a blank organic phase.

2. A method for separating and recovering metal elements from the leaching solution of waste ternary lithium-ion batteries, comprising the following steps: A) Mixing an extractant 2-n-hexyldecanoic acid with a diluent to obtain an extraction solvent; B) Mixing the extraction solvent with a saponifying agent to obtain a saponified extraction solvent; C2) Mixing the leaching solution of waste ternary lithium-ion batteries, the saponified extraction solvent and a detergent for 6-10 stage countercurrent extraction and 7-10 stage countercurrent washing to obtain a washed organic phase; D2) Mixing the washed organic phase with a stripping agent for 3-5 stage countercurrent stripping to obtain a stripping solution and a blank organic phase.

3. The method according to claim 1 or 2, characterized in that, In step A), the diluent is selected from GV-18A, kerosene or solvent oil.

4. The method according to claim 1 or 2, characterized in that, In step A), in the extraction solvent, the volume concentration of the extractant is 5% - 35%.

5. The method according to claim 1 or 2, characterized in that, In step B), the saponifying agent is selected from sodium hydroxide solution, ammonia water, sodium carbonate solution or ammonium carbonate solution.

6. The method according to claim 1 or 2, characterized in that, In step B), the saponification degree of the saponified extraction solvent is 10% - 40%.

7. The method according to claim 1 or 2, characterized in that, The metal elements contained in the leaching solution of the waste ternary lithium-ion batteries include nickel, cobalt, manganese, lithium, calcium and magnesium.

8. The method according to claim 1 or 2, characterized in that, The temperature of the extraction is 20 - 30 °C and the time is 10 - 20 min; The extraction is carried out under the condition of shaking.

9. The method according to claim 1 or 2, characterized in that, The stripping agent is sulfuric acid; the concentration is 0.5 - 2.5 mol / L.

10. The method according to claim 1 or 2, characterized in that, The temperature of the stripping is 20 - 30 °C and the time is 10 - 20 min; The stripping is carried out under the condition of shaking.

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