Novel process for comprehensively recovering valuable metals in ternary positive electrode material powder

Abstract

The invention provides a new process for comprehensively recovering valuable metals in ternary positive electrode material powder, which comprises the steps of positive electrode material powder dissolution, metal salt separation, extraction and reverse extraction, lithium salt treatment and the like, acid obtained by electrolysis can be recycled, and a lithium salt solution can be further used for preparing a lithium carbonate product. The process has the remarkable advantages that resource recovery is comprehensive and efficient, the valuable metal recovery rate is high, and the metal separation precision is high; the process is environment-friendly and low in cost, auxiliary materials are recycled, the cost is reduced, and environmental pollution is reduced; the product is excellent in quality, low in impurity content and stable in performance, can meet high-end market requirements, and improves the market competitiveness and the added value. The process has outstanding advantages in the aspects of resource recovery, environmental protection cost, product quality and the like, and has wide application prospects and market values.

Description

Technical Field

[0001] The invention relates to a new process for comprehensively recovering valuable metals in ternary positive electrode material powder. Background Art

[0002] With the rapid development of new energy vehicles, electronic equipment and other industries, the use of ternary lithium batteries and lithium iron phosphate batteries has increased dramatically. After these lithium batteries reach their service life, some of the better performance ones will be used in a gradient manner, while most of them will be directly scrapped and disassembled, and the positive electrode will be ground into powder. A large amount of ternary positive electrode material powder generated after its scrapping needs to be effectively treated and recycled. However, the existing ternary positive electrode material powder recovery process is mainly based on wet process, which has many problems: in terms of resource recovery, the traditional process is not comprehensive enough for the recovery of valuable metals, such as nickel, cobalt, manganese, lithium and other valuable metals are difficult to achieve efficient recovery, and the recovery rate is low, resulting in a large amount of resource waste, unable to fully meet the needs of resource recycling, and is not conducive to the improvement of corporate economic benefits and the practice of sustainable development concepts. During the production process, the lithium content in the lithium salt solution is low, and lithium and alkali metal salts such as sodium and potassium are mixed together, which is difficult to effectively separate, resulting in a low lithium recovery rate.

[0003] In the metal separation process, traditional processes often lack precise separation methods, making it difficult to effectively separate lithium salt solutions from nickel, cobalt, and manganese metal salt solutions. This results in a high impurity content in the subsequent metal salt treatment process, low product quality, and low direct recovery rates of various valuable metals, which in turn affects the added value of the products and limits the competitiveness of companies in the market. From the perspective of environmental protection and cost, auxiliary materials such as acids and alkalis in traditional processes are consumables necessary for production and cannot be recycled. New auxiliary materials need to be purchased continuously, resulting in high auxiliary material costs. At the same time, a large amount of acid, alkali and other auxiliary materials used in the production process will produce pollutants such as sodium salts that will undergo neutralization reactions and produce a large amount of salt. The salt solution produced by the company has no good treatment method and can only be discharged externally. The large amount of wastewater, waste gas, and waste residue discharged not only increases the cost of environmental pollution control, but also makes it difficult to meet increasingly stringent environmental protection requirements, posing a severe challenge to the sustainable development of enterprises. In addition, traditional processes often use chemical impurity removal methods during the impurity removal process, which easily introduces additional impurities, resulting in low purity and poor quality of nickel salts, cobalt salts, manganese salts, lithium carbonate or lithium hydroxide products, which can only reach industrial-grade products. If companies want to produce high-quality products, they need to further purify industrial-grade products, which greatly increases their production costs. It is impossible to meet the high-end market's demand for high-quality battery materials, which in turn affects the development and upgrading of related industries.

[0004] To sum up, the existing technology has many shortcomings in the comprehensive utilization of ternary positive electrode material powder. There is an urgent need for a new process that can comprehensively and efficiently recycle resources, is environmentally friendly, low-cost, and has excellent product quality to solve these problems. The present invention is based on this background and proposes a new process for comprehensive recovery of valuable metals in ternary positive electrode material powder. Summary of the invention

[0005] The purpose of the present invention is to provide a new process for comprehensively recovering valuable metals in ternary positive electrode material powder to solve the problems raised in the above-mentioned background technology.

[0006] In order to solve the above technical problems, the technical solution provided by the present invention is: a new process for comprehensive recovery of valuable metals in ternary positive electrode material powder, which specifically comprises the following steps:

[0007] 1) Dissolving positive electrode material powder: slurry the positive electrode material powder of the ternary battery, then add acid for acid hydrolysis, and perform solid-liquid separation after sufficient reaction to obtain activated carbon powder and leaching solution. The activated carbon powder needs to be countercurrent washed 2-3 times to ensure the leaching rate;

[0008] 2) Separation of metal salt solution: The leachate passes through a liquid separation device to separate lithium salt solution and nickel, cobalt, and manganese metal salt solutions;

[0009] 3) Extraction and stripping: Extract the separated nickel, cobalt and manganese metal salts to extract nickel salts and cobalt salts. The sodium salt raffinate passes through a saponifying extractant and enters an electrolysis device to obtain sodium hydroxide and acid by electrolysis. The solution and the saponified P204 extractant organic solution are extracted. Metal ions such as nickel and cobalt will replace the sodium ions in the extractant and enter the organic phase. The replaced sodium ions enter the raffinate. This process is extraction. The saturated organic phase is stripped with a sulfuric acid solution of a certain concentration to obtain nickel sulfate and sulfuric acid solution. After passing through P507 to separate nickel sulfate and cobalt sulfate, the nickel sulfate and sulfuric acid solution are evaporated and crystallized to obtain nickel sulfate and cobalt sulfate products. Nickel sulfate and cobalt sulfate can also be processed into nickel oxide and cobalt oxide. The empty organic phase is acid-washed and then saponified again.

[0010] 4) Treatment of raffinate: In the conventional process, the raffinate can only be discharged. In the present invention, the raffinate is electrolyzed by bipolar membrane to regenerate sulfuric acid solution and sodium hydroxide solution;

[0011] 5) Lithium salt treatment: The separated lithium salt solution is subjected to bipolar membrane electrolysis to produce hydrochloric acid solution and lithium hydroxide solution. The lithium hydroxide solution is evaporated and crystallized to produce lithium hydroxide monohydrate product.

[0012] As a preferred solution, the sulfuric acid solution obtained by electrolysis in step 4) is used for 1) front-stage acid hydrolysis of the positive electrode material powder, and the sodium hydroxide solution obtained by electrolysis is used for saponification of the empty organic phase in 3).

[0013] As a preferred embodiment, the hydrochloric acid solution obtained by electrolysis in step 5) is used for 1) acid hydrolysis of positive electrode material powder, and the lithium hydroxide solution obtained by electrolysis can be evaporated and crystallized to prepare lithium hydroxide monohydrate solution, or carbon dioxide can be introduced to prepare lithium carbonate; the prepared lithium hydroxide monohydrate or lithium carbonate can be slightly processed to prepare battery-grade products.

[0014] As a preferred solution: the acid used for acidolysis in step 1) is a mixed acid of sulfuric acid and hydrochloric acid obtained by electrolysis in 4) and 5).

[0015] As a preferred embodiment, the salt solution in step 2) contains SO4 2- , Cl - , Li + , Ni 2+ ,Co 2+ The solution can pass through the nanofiltration membrane to - , Li + With SO4 2- , Ni 2+ ,Co 2+ Effective separation to obtain LiCl solution and other metal sulfate solutions.

[0016] As a preferred embodiment, the salt solution to be separated in step 2) is lithium chloride solution and other sulfate solutions.

[0017] The advantages of the present invention are: 1. Comprehensive and efficient resource recovery

[0018] High recovery rate of valuable metals: This process can effectively separate lithium from other high-valent metals such as nickel and cobalt, greatly improving the direct recovery rate of lithium. For example, the use of nanofiltration membranes can effectively separate monovalent anions and cations from high-valent anions and cations, preventing lithium ions from entering subsequent processes and improving the direct recovery rate of lithium. This process separates lithium from other divalent metals before the leaching solution enters the extraction process, preventing lithium from mixing with sodium salts in subsequent processes, and ultimately making it difficult to effectively separate it from sodium. It achieves the maximum recycling of resources, brings considerable economic benefits to the enterprise, and also conforms to the concept of sustainable resource utilization. The bipolar membrane electrolysis used in the present invention can effectively increase the concentration of the lithium hydroxide solution obtained by electrolysis, solving the problem of low lithium recovery rate caused by the low concentration of the lithium solution obtained in the production process of recycled materials.

[0019] This ensures the purity and efficiency of subsequent metal salt treatments. This precise separation lays a good foundation for subsequent extraction, stripping, and lithium salt treatment, avoiding problems such as high impurity content and low quality of products caused by incomplete metal separation, and improves the product quality and added value of the entire process.

[0020] 2. The process is environmentally friendly and low cost

[0021] Recycling of auxiliary materials to reduce costs: The acid obtained by electrolysis in step 4) is circulated to dissolve the positive electrode material powder, which realizes the recycling of acid, greatly reduces the acid consumption, and reduces the cost of auxiliary materials. At the same time, in the entire process, all acids (such as sulfuric acid, hydrochloric acid, etc.) and alkalis (such as sodium hydroxide, etc.) can be recycled, and there is no need to discharge sodium salt. This not only saves a lot of auxiliary material procurement costs, but also reduces the cost of environmental pollution control caused by the discharge of auxiliary materials, and has significant economic and environmental benefits. According to calculations, compared with traditional processes, this process can reduce the cost of auxiliary materials by more than 80%, saving the company a lot of money.

[0022] Reduce environmental pollution: Due to the recycling of auxiliary materials such as acid and alkali in the process and the absence of pollutants such as sodium salt, the pollution to the environment is greatly reduced. Compared with traditional processes, this process significantly reduces the discharge of wastewater, waste gas and waste residue, meets the current strict environmental protection requirements, is conducive to the sustainable development of enterprises, and also makes a positive contribution to environmental protection.

[0023] 3. Excellent product quality

[0024] Low impurity content: This process does not use the traditional chemical impurity removal method during the impurity removal process, so no additional impurities will be introduced, ensuring that the nickel salt, cobalt salt, manganese salt products and lithium carbonate or lithium hydroxide products produced have higher purity and better quality, which are superior to products produced by traditional processes. It can better meet the high-end market's demand for high-quality battery materials and improve the market competitiveness and added value of the products.

[0025] Stable product performance: Due to the low impurity content of the product, its performance is more stable and reliable. For example, when the lithium hydroxide products produced by this process are used in battery manufacturing, they can significantly improve the battery's charge and discharge performance, cycle life and safety, providing a better quality battery material guarantee for new energy vehicles, electronic equipment and other fields, and helping to promote the development and upgrading of related industries.

[0026] In summary, this process has significant advantages in resource recovery, environmental protection costs, product quality, etc., and has broad application prospects and market value. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a process flow chart of the present invention.

[0028] Figure 2 This is a schematic diagram of bipolar membrane electrolysis of lithium chloride. DETAILED DESCRIPTION

[0029] For the purpose of the following detailed description, it should be understood that the present invention may adopt various alternative changes and step sequences, unless expressly specified to the contrary. In addition, except in any operating examples, or otherwise indicated, all numbers representing the amount of ingredients used in the specification and claims should be understood to be modified by the term "about" in all cases. Therefore, unless otherwise indicated, the numerical parameters set forth in the following specification and the attached claims are approximate values ​​that vary according to the desired performance to be obtained by the present invention. At least it is not intended to limit the application of the doctrine of equivalents to the scope of the claims, and each numerical parameter should at least be interpreted according to the number of reported significant figures and by applying ordinary rounding techniques.

[0030] Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values ​​set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements.

[0031] In addition, it should be understood that any numerical range described herein is intended to include all subranges subsumed therein. For example, a range of "1 to 10" is intended to include all subranges between (and including) the stated minimum value of 1 and the stated maximum value of 10, i.e., having a minimum value equal to or greater than 1 and a maximum value equal to or less than 10.

[0032] Embodiment 1:

[0033] Experimental materials and equipment: prepare the positive electrode material powder of ternary battery, select sulfuric acid as the dissolving acid, equip with solid-liquid separation equipment, liquid separation device, extraction equipment, electrolysis equipment, ternary battery positive electrode recovery material powder, 15% dilute sulfuric acid, stirred reactor, nanofiltration system, bipolar membrane stack, extraction system, lithium precipitation reactor, lithium precipitation filter, etc.

[0034] Process steps:

[0035] According to step 1 of the above new process, the ternary battery positive electrode recovery material powder is added to a 15% dilute sulfuric acid solution at a ratio of L:S=5:1 to dissolve, and the reaction temperature and time are controlled. After the material is fully dissolved, it is pressed into a plate frame for solid-liquid separation. The activated carbon powder undergoes two countercurrent washes to ensure the leaching rate. The equipment operation and the actual operation process are recorded, the weight of the activated carbon powder and the volume of the leachate are accurately weighed, and samples are taken for analysis. Ensure that the material is fully dissolved, and then perform solid-liquid separation to obtain activated carbon powder and leachate. In this step, by precisely controlling the dissolution conditions, the valuable metals are dissolved more fully, laying the foundation for the subsequent high recovery rate, reflecting the advantages of the high recovery rate of valuable metals. At the same time, the amount of washing water must be strictly controlled to ensure the recovery rate while preventing the expansion of the liquid.

[0036] The leaching solution is pumped into the nanofiltration system through a high-pressure pump to separate lithium from other divalent metals. At the same time, the equipment operation status and operation process are recorded, and the volume of the dilute solution and the concentrated solution are accurately recorded and sampled for analysis.

[0037] Analysis of experimental results: Analysis and calculation of valuable metals such as lithium, nickel, cobalt, and manganese in activated carbon powder, leaching solution, and washing water showed that the leaching rate of valuable metals was 95%.

[0038] After analyzing and comparing the dilute liquid and concentrated liquid after the leaching solution entered the nanofiltration system, it was found that about 90% of the lithium and other divalent metals were intercepted in the concentrated water by the nanofiltration membrane, and the nanofiltration system did not play the role of separating lithium and other divalent metals.

[0039] The experiment did not achieve effective separation of lithium and other divalent metals, did not achieve the expected results, and there was no need to continue with extraction and bipolar membrane electrolysis.

[0040] Embodiment 2:

[0041] Experimental materials and equipment: Take another portion of ternary battery positive electrode material powder, this time use 15% hydrochloric acid as the dissolving acid, and other equipment is the same as Example 1.

[0042] Process steps:

[0043] The same operation of dissolving the positive electrode material powder was carried out. After adding 15% hydrochloric acid, the ternary positive electrode material powder was put into the 15% hydrochloric acid solution at a ratio of L:S=5:1. The reaction parameters, such as temperature and stirring speed, were precisely controlled to fully dissolve the positive electrode material powder. Then, it was pressed into the plate frame for solid-liquid separation. After two countercurrents, the amount of washing water was strictly controlled to ensure the leaching rate and prevent liquid expansion. The equipment operation and actual operation process were recorded, the weight of the activated carbon powder and the volume of the leaching solution were accurately weighed, and samples were taken for analysis.

[0044] The leaching liquid is pumped into the nanofiltration system, and the equipment operation and operation process are recorded. The volume of the dilute liquid and the concentrated liquid is accurately recorded and sampled for analysis. The leaching liquid is separated by a liquid separation device, which can accurately separate the lithium salt solution from the nickel, cobalt and manganese metal salts. The separation effect is good, ensuring the purity of each metal salt, providing high-quality raw materials for subsequent processing, and reflecting the advantage of high metal separation accuracy.

[0045] The experiment used hydrochloric acid leaching, and the entire system was a chloride salt system. Combined with actual production conditions and production experience, a large amount of hydrogen chloride gas and chlorine gas will be produced during the extraction process of the chloride salt system, which will seriously affect the air in the production workplace and cause serious equipment corrosion. Therefore, this experiment only explores the separation of lithium and other divalent metals in the chloride salt system by nanofiltration membranes, so the experiment did not extract and electrolyze metal chloride salts.

[0046] Analysis of experimental results: After data analysis, the leaching rate of the ternary positive electrode material powder is 96%.

[0047] Analysis of the nanofiltration membrane dilute liquid and concentrated liquid shows that in the chloride salt system, more than 95% of lithium chloride will not be intercepted by the nanofiltration membrane and enter the dilute liquid, while other divalent and high-valent metals will be completely intercepted by the nanofiltration membrane. Therefore, it can be concluded that effective separation of lithium and other divalent and high-valent metals can be achieved in the chloride salt system.

[0048] Embodiment 3:

[0049] Experimental materials and equipment: Select ternary battery positive electrode material powder, and use mixed acid as dissolving acid (the amount of hydrochloric acid is 1.2 times the theoretical amount of total lithium in the ternary positive electrode material powder, and the rest is sulfuric acid). The equipment is consistent with the previous two embodiments.

[0050] Process steps:

[0051] To dissolve the positive electrode material powder, add the ternary positive electrode material powder into the mixed acid at a ratio of L:S=5:1. According to the characteristics of this batch of material powder, accurately adjust the dissolution conditions, including temperature, acidity, reaction time, etc., and repeat the solid-liquid separation and nanofiltration membrane separation steps of lithium and other divalent metals in Experiment 1 and Experiment 2.

[0052] The leaching rate of valuable metals in this experiment was 95%. The concentrated solution after nanofiltration was a sulfate solution of high-valent metals such as nickel, cobalt, and manganese, and the diluted solution was a lithium chloride solution.

[0053] The leachate is separated by a liquid separation device, which can accurately separate the lithium salt solution from nickel, cobalt and manganese metal salts with its high-precision separation performance. The metal salt solutions after separation are of high purity, which provides a good foundation for subsequent extraction and stripping as well as lithium salt treatment steps, demonstrating the advantage of high metal separation accuracy.

[0054] The nanofiltration membrane concentrate (sulfate solution of high-valent metals such as nickel, cobalt, and manganese) is subjected to extraction, nickel-cobalt separation, stripping and other related operations to obtain nickel sulfate and cobalt sulfate solutions, which are then further processed to obtain related nickel and cobalt products.

[0055] Since the industrial production process of sulfate extraction of nickel and cobalt is very mature, it will not be described in detail in the present invention.

[0056] The lithium content in the nanofiltration membrane dilute liquid (lithium chloride solution) is low (the lithium content and the lithium content in the ternary positive electrode material powder are related to the solid ratio of the leaching solution, and the lithium content in this experiment is 4g / L), which is not suitable for direct production of lithium carbonate. This experiment uses bipolar membrane electrolysis to produce lithium carbonate or lithium hydroxide: lithium chloride solution (nanofiltration membrane dilute liquid) enters the bipolar membrane stack through a delivery pump, and under the action of a DC electric field, lithium hydroxide solution is produced and enriched in the anode chamber, and hydrochloric acid solution is produced and enriched in the cathode chamber.

[0057] The lithium hydroxide solution produced by bipolar membrane electrolysis is pumped into the lithium precipitation reactor, the temperature is controlled at 80℃-90℃, and carbon dioxide gas is introduced to keep the pressure in the reactor unchanged, control the pH value at the reaction end point, and prevent excessive carbon dioxide from generating lithium bicarbonate. After the reaction is complete, the lithium carbonate is separated through the lithium precipitation filter, and the battery-grade lithium carbonate product can be obtained after drying and crushing. The lithium carbonate mother liquor is recycled. The lithium hydroxide solution can also be evaporated and crystallized by MVR evaporator to produce monohydrate lithium hydroxide product. Due to the strict control of impurities in the entire process, the traditional chemical impurity removal method is not used to avoid the introduction of impurities. The monohydrate lithium hydroxide and lithium carbonate products produced are of high purity and excellent quality, and show excellent performance in battery applications, such as high charge and discharge efficiency, long cycle life, good safety, etc., which highlights the excellent quality of the products, can better meet the needs of the high-end market, and improve the market competitiveness and added value of the products.

[0058] Embodiment 4:

[0059] Raw materials and equipment: the raffinate in the extraction in Example 3, P204 extractant, P507 extractant, bipolar membrane stack, purification reactor, extractant saponification box.

[0060] Process steps:

[0061] The raffinate (sodium sulfate solution) after the nanofiltration membrane concentrate is extracted in Example 3 is purified and then electrolyzed using a bipolar membrane stack. Under the action of a DC electric field, a sodium hydroxide solution is produced and enriched in the anode chamber, and a sulfuric acid solution is produced and enriched in the cathode chamber.

[0062] The produced sodium hydroxide solution and the empty organic phase (P507, P204) are saponified according to the saponification rate required for production. After the organic phase is saponified, it enters the extraction process.

[0063] The generated sulfuric acid solution is mixed with the hydrochloric acid solution generated by the electrolysis of lithium chloride in Example 3 to jointly acid-hydrolyze the ternary positive electrode material powder.

[0064] The above experiments prove that:

[0065] 1. The use of nanofiltration membrane in the present invention can effectively separate lithium and other divalent high-valent metals in the leaching solution of ternary positive electrode material powder, perfectly solving the difficulty of completely separating lithium from other metals in traditional processes, and greatly reducing the consumption of auxiliary materials for separating lithium and other metal ions in traditional processes.

[0066] 2. The method for preparing lithium hydroxide and lithium carbonate from lithium chloride by bipolar membrane stack electrolysis in the present invention is different from the traditional lithium carbonate and lithium hydroxide production process. It does not use auxiliary materials such as sodium carbonate, sodium hydroxide, and lime. Compared with sodium carbonate, carbon dioxide does not introduce impurity metal ions, thereby improving the quality of lithium carbonate products. Lithium hydroxide is completely obtained by electrolysis, and no auxiliary materials such as sodium hydroxide or lime are used. At the same time, the processes such as causticization and freezing sodium removal are also eliminated, which greatly shortens the process flow, avoids the introduction of impurities, improves product quality, and does not produce intermediate products such as sodium sulfate decahydrate, thereby greatly improving the direct yield of the product.

[0067] 3. The raffinate after extraction of divalent metals such as nickel and cobalt can be used for preparing sulfuric acid solution and sodium hydroxide solution by bipolar membrane stack electrolysis after simple treatment. The hydrochloric acid solution produced by the electrolysis of sulfuric acid solution and lithium chloride is used as the acid for the acid hydrolysis of ternary positive electrode material powder, which realizes the recycling of acid, reduces the cost of purchasing auxiliary materials of sulfuric acid and hydrochloric acid, and also reduces the risk of introducing impurities. Sodium hydroxide can be directly saponified with the extracted organic phase, eliminating the cost of purchasing auxiliary materials of sodium hydroxide sodium salt, and also reduces the risk of introducing impurities.

[0068] In summary, the present invention effectively separates and recycles valuable metals such as lithium, nickel, and cobalt in the process of recovering ternary positive electrode material powder. In the process of preparing lithium hydroxide and lithium carbonate, auxiliary materials such as sodium carbonate and sodium hydroxide are no longer used, which greatly saves the cost of auxiliary materials and also improves product quality. The acid used for leaching and the alkali used for saponification are all produced by system circulation, which truly realizes the recycling of resources and reduces the discharge of brine. Therefore, it has unparalleled advantages in saving costs, improving product quality, and reducing pollution emissions.

[0069] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A new process for comprehensive recovery of valuable metals in ternary positive electrode material powder, characterized in that: The specific steps include: 1) Dissolving positive electrode material powder: slurry the positive electrode material powder of the ternary battery, then add acid for acid hydrolysis, and perform solid-liquid separation after sufficient reaction to obtain activated carbon powder and leaching solution. The activated carbon powder needs to be countercurrent washed 2-3 times to ensure the leaching rate; 2) Separation of metal salt solution: The leachate passes through a liquid separation device to separate lithium salt solution and nickel, cobalt, and manganese metal salt solutions; 3) Extraction and stripping: Extract the separated nickel, cobalt and manganese metal salts to extract nickel salts and cobalt salts. The sodium salt raffinate passes through a saponifying extractant and enters an electrolysis device to obtain sodium hydroxide and acid by electrolysis. The solution and the saponified P204 extractant organic solution are extracted. Metal ions such as nickel and cobalt will replace the sodium ions in the extractant and enter the organic phase. The replaced sodium ions enter the raffinate. This process is extraction. The saturated organic phase is stripped with a sulfuric acid solution of a certain concentration to obtain nickel sulfate and sulfuric acid solution. After passing through P507 to separate nickel sulfate and cobalt sulfate, the nickel sulfate and sulfuric acid solution are evaporated and crystallized to obtain nickel sulfate and cobalt sulfate products. Nickel sulfate and cobalt sulfate can also be processed into nickel oxide and cobalt oxide. The empty organic phase is acid-washed and then saponified again. 4) Treatment of raffinate: In the conventional process, the raffinate can only be discharged. In the present invention, the raffinate is electrolyzed by bipolar membrane to regenerate sulfuric acid solution and sodium hydroxide solution; 5) Lithium salt treatment: The separated lithium salt solution is subjected to bipolar membrane electrolysis to produce hydrochloric acid solution and lithium hydroxide solution. The lithium hydroxide solution is evaporated and crystallized to produce lithium hydroxide monohydrate product.

2. According to claim 1, a new process for comprehensive recovery of valuable metals in ternary positive electrode material powder is characterized by: The sulfuric acid solution obtained by electrolysis in step 4) is used for acid hydrolysis of the positive electrode material powder in the front stage of 1), and the sodium hydroxide solution obtained by electrolysis is used for saponification of the empty organic phase in 3).

3. The new process for comprehensive recovery of valuable metals in ternary positive electrode material powder according to claim 1 is characterized by: The hydrochloric acid solution obtained by electrolysis in the step 5) is used for 1) acid hydrolysis of positive electrode material powder. The lithium hydroxide solution obtained by electrolysis can be evaporated and crystallized to prepare lithium hydroxide monohydrate solution, or carbon dioxide can be introduced to prepare lithium carbonate; the prepared lithium hydroxide monohydrate or lithium carbonate can be slightly processed to prepare battery-grade products.

4. The new process for comprehensive recovery of valuable metals in ternary positive electrode material powder according to claim 1 is characterized by: The acid used for acidolysis in step 1) is a mixed acid of sulfuric acid and hydrochloric acid obtained by electrolysis in step 4) and 5).

5. The new process for comprehensive recovery of valuable metals in ternary positive electrode material powder according to claim 1 is characterized by: The salt solution in step 2) contains SO4 2- , Cl - , Li + , Ni 2+ ,Co 2+ The solution can pass through the nanofiltration membrane to - , Li + With SO4 2- , Ni 2+ ,Co 2+ Effective separation to obtain LiCl solution and other metal sulfate solutions.

6. The new process for comprehensive recovery of valuable metals in ternary positive electrode material powder according to claim 1 is characterized by: The salt solution to be separated in step 2) is lithium chloride solution and other sulfate solution.

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