Method for recovering valuable metal from waste nickel-iron-manganese precursor

Abstract

The invention discloses a method for recovering valuable metals from a waste nickel-iron-manganese precursor, which comprises the following steps: firstly, dispersing waste materials in pure water according to a mass ratio of (0.4-0.6): 1 to obtain a first mixed solution; then, an acid solution is added, the layered structure is destroyed through the reaction between the acid solution and OH <-> in the material, metal ions such as nickel, iron and manganese are dissolved out, and a second mixed solution is obtained; then, an oxidizing agent is added, low-valence metal ions are oxidized into high-valence metal ions (for example, Fe < 2 + > is converted into Fe < 3 + >), the dissolving efficiency is improved, and a third mixed solution is obtained after solid impurities are filtered out; and then, adding a reducing agent into the third mixed solution, selectively reducing Fe < 3 + > into Fe < 2 + >, and filtering again to obtain a solution rich in nickel, iron and manganese ions. The method is short in process and easy and convenient to operate, the metal proportion in the obtained solution can be adjusted according to needs, the solution can be directly used for synthesizing a new precursor, the recovery cost is remarkably lower than that of traditional hydrometallurgy, and good industrialization prospects are achieved.

Description

Technical Field

[0001] This invention relates to the field of recycling waste battery materials, specifically to a method for recovering valuable metals from waste nickel-iron-manganese precursors. Background Technology

[0002] Sodium-ion batteries are considered an important supplement to lithium-ion batteries due to their abundant resources and cost potential, especially in new energy vehicles and large-scale energy storage. The cathode material of sodium-ion batteries is crucial in determining their performance. Among them, layered oxide cathode materials, particularly those based on the nickel-iron-manganese (Ni-Fe-Mn) system, have become a key focus of current research and industrialization due to their high specific capacity (approaching that of existing lithium iron phosphate materials).

[0003] The nickel-iron-manganese layered oxide cathode material is typically prepared using its corresponding nickel-iron-manganese ternary precursor as raw material. The mainstream synthesis method for this precursor is liquid-phase co-precipitation, and its process route is highly similar to that of lithium-ion battery cathode material precursors, which gives existing production lines the potential for rapid production conversion.

[0004] However, a significant technical challenge exists in the synthesis of the nickel-iron-manganese precursor using the co-precipitation method, especially in systems with iron-based materials as the main raw material: during the reaction, the divalent iron ions (Fe2+) in the metal salt solution... 2+ It is readily oxidized to ferric ions (Fe3+) by oxygen in the air or dissolved oxygen in the solution. 3+ Fe 3+ Precipitation will preferentially hydrolyze to form ferric hydroxide precipitate. These precipitates act as nuclei, triggering localized and irregular precipitation reactions, leading to the precipitation of a large number of undesirable small seed crystals. This phenomenon disrupts the stability of the co-precipitation system, causing runaway reactions and resulting in a particle size distribution (PSD) of the final precursor secondary particles deviating from the design range, with poor sphericity. Ultimately, this affects key electrochemical indicators of the cathode material, such as tap density, capacity, and cycle performance. To suppress this problem, existing technologies typically require strict control of Fe in the reaction environment. 3+ The concentration (e.g., not exceeding 0.06 g / L) is required, but this places extremely high demands on equipment sealing, inert gas protection, and process parameter control, increasing production difficulty and cost.

[0005] Furthermore, due to the extremely stringent requirements of the synthesis environment, raw material purity, operational precision, and equipment for the precursor materials, a certain proportion of substandard scrap products inevitably arises during actual large-scale production. Currently, the mainstream approach in the industry for processing such scrap nickel-iron-manganese precursor materials is hydrometallurgical processing, which involves leaching valuable metal elements with acid, followed by extraction, separation, and purification, before finally reusing them for precursor synthesis. While this route is technically mature, it suffers from complex processes, high equipment investment, high energy consumption, and the potential generation of secondary wastewater, resulting in high overall recycling costs.

[0006] The existing synthesis process of nickel-iron-manganese layered oxide cathode material precursors has Fe 2+ The ease of oxidation leads to production control challenges resulting in poor product consistency. Furthermore, there is a lack of an economical, efficient, and simple method for recycling and reusing the waste generated during the production process. This restricts further reductions in the cost of sodium-ion battery materials and the recycling of resources.

[0007] Therefore, how to overcome the shortcomings of the existing technology is the subject of this invention. Summary of the Invention

[0008] The purpose of this invention is to provide a method for recovering valuable metals from waste nickel-iron-manganese precursors.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0010] A method for recovering valuable metals from scrap nickel-iron-manganese precursors includes:

[0011] Step 1: Disperse the waste nickel-iron-manganese precursor material in pure water to obtain a first mixture. The mass ratio of the waste nickel-iron-manganese precursor material to pure water in the first mixture is controlled at (0.4~0.6):1.

[0012] Step 2: Add the acid solution to the first mixture, utilizing the reaction between the acid solution and the OH- in the waste nickel-iron-manganese precursor. - The reaction disrupts its layered structure, releasing metal ions containing nickel, iron, and manganese, resulting in a second mixture.

[0013] Step 3: Add the oxidant solution to the second mixture to oxidize the low-valence metal ions to high-valence states, improving the dissolution efficiency. Then filter out the solid impurities to obtain the third mixture. At this point, the third mixture contains nickel, iron, and manganese metal ions, wherein the iron ions are oxidized to Fe... 2+ It turned into Fe 3+ ;

[0014] Step 4: Add the reducing agent to the third mixture, using the reducing agent to remove Fe from the third mixture. 3+ Reduced to Fe 2+ After filtration, a nickel-iron-manganese metal solution is obtained.

[0015] In the above-mentioned scheme, the waste nickel-iron-manganese precursor material referred to in this invention specifically refers to defective or scrap products resulting from one or more key indicators failing to meet standards during the original manufacturing process, rather than materials recycled from batteries that have been scrapped after use. Specifically, it refers to nickel-iron-manganese based composite hydroxides whose chemical composition (such as the ratio of metal elements and impurity content), physical properties (such as particle size and tap density), or microstructure (such as sphericity and density) does not meet the standards for commercial ternary cathode material precursors.

[0016] In a further technical solution, the acid solution is added at a rate of 2-10 mL / min, and the liquid-solid ratio of the acid solution added to the waste nickel-iron-manganese precursor material is 1-5 mL / g.

[0017] Adding the acid solution too quickly will cause the leaching reaction to proceed violently, resulting in severe exothermic reactions. Violent reactions at high temperatures can lead to splashing and safety hazards, and accelerate acid reduction, generating elemental sulfur and hydrogen sulfide. A further preferred rate is 3~6 mL / min.

[0018] In a further technical solution, in step one, the liquid-to-solid ratio of water to the waste nickel-iron-manganese ternary precursor material is 1~5 mL / g. More preferably, it is 2~4 mL / g.

[0019] In a further technical solution, the reaction conditions in step two include: pH value of 0.2~3, temperature of 60~80℃, and time of 1~4h.

[0020] A further technical solution involves adding the oxidant solution at a rate of 1-5 mL / min in step three. Adding the oxidant too quickly will cause the reaction to proceed violently, resulting in significant exothermic reactions and potentially leading to splashing and safety hazards at high temperatures. Adding the oxidant too slowly will result in an excessively long reaction time, which is detrimental to production.

[0021] The reaction conditions include: pH value of 0.2~3, temperature of 60~80℃, time of 2~6h, liquid-solid ratio of oxidant solution to waste nickel-iron-manganese precursor material of 1~3mL / g, and no visible impurities in the clear liquid of the third mixture before filtration.

[0022] In a further technical solution, in step four, the amount of reducing agent added is controlled at 10~30g / L.

[0023] In a further technical solution, the acid solution is selected from at least one of hydrochloric acid solution, sulfuric acid solution, nitric acid solution, and phosphoric acid solution;

[0024] The concentration of the acid solution is 2~10 mol / L.

[0025] In a further technical solution, the reducing agent is selected from at least one of iron powder, oxalic acid, and zinc powder.

[0026] In a further technical solution, the oxidant solution is selected from at least one of hydrogen peroxide solution, sodium persulfate solution, and sodium chlorate solution.

[0027] The terms “include,” “including,” and “have” used in this article are all open-ended, meaning they include but are not limited to.

[0028] Unless otherwise specified, the terms used herein generally have their ordinary meaning in the context of the art, the subject matter, and the specific context. Certain terms used to describe this case will be discussed below or elsewhere in this specification to provide additional guidance to those skilled in the art in describing the case.

[0029] The working principle and advantages of this invention are as follows:

[0030] This invention relates to a method for recovering valuable metals from waste nickel-iron-manganese precursors, the method comprising:

[0031] Acid leaching step: The waste material is treated with an acid solution to destroy its layered structure and leach out metal ions to obtain a leachate;

[0032] Oxidation and impurity removal step: An oxidant is added to the leachate, and the Fe in the solution is removed by controlling the dropping rate of the oxidant. 2+ Oxidized to Fe 3+ A precipitate forms, and after solid-liquid separation, impurities are removed to obtain a purified liquid.

[0033] Reduction control step: The purified solution is analyzed for composition, and a reducing agent is added to remove the remaining Fe. 3+ Reduced to Fe 2+ This causes Fe in the solution 3+ The concentration of the metal salt is reduced to below a predetermined threshold (e.g., ≤0.06 g / L) to obtain a mixed metal salt solution that meets the requirements for precursor synthesis.

[0034] The mixed metal salt solution recovered by this invention has a nickel, iron, and manganese ratio that can be adjusted stoichiometrically, and can be directly used to synthesize new nickel-iron-manganese precursors. This method is concise, simple to operate, and has significantly lower recovery costs than traditional hydrometallurgical processes, showing promising prospects for industrial application. Attached Figure Description

[0035] Appendix Figure 1This is a schematic diagram of the method flow of Embodiments 1 to 3 of the present invention. Detailed Implementation

[0036] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0037] The present invention will be clearly described below with illustrations and detailed description. Any person skilled in the art who understands the embodiments of the present invention can make changes and modifications based on the technology taught in the present invention without departing from the spirit and scope of the present invention.

[0038] The terminology used herein is for the purpose of describing specific embodiments only and is not intended to limit the scope of this work. Singular forms such as “a,” “this,” “this,” “the,” and “the” as used herein also include plural forms.

[0039] Example 1: First, 200g of waste nickel-iron-manganese precursor material was placed in 400mL of pure water and stirred and dispersed thoroughly using a magnetic stirrer;

[0040] Sulfuric acid with a concentration of 7.14 mol / L is injected using a peristaltic pump (the flow rate of sulfuric acid is controlled at 5 mL / min). The reaction temperature is controlled at 60~80℃. If the reaction temperature exceeds the upper limit, the injection of sulfuric acid is stopped. The injection is resumed after the temperature drops to the required range. The injection of sulfuric acid is stopped after 600 mL of sulfuric acid has been injected.

[0041] Then, hydrogen peroxide with a concentration of 9.79 mol / L is injected through a peristaltic pump (the flow rate of hydrogen peroxide is controlled at 1 mL / min). The reaction temperature is controlled at 60~80℃. If the reaction temperature exceeds the upper limit, the injection of hydrogen peroxide is stopped. After the temperature drops to the required range, the injection is resumed. After 200 mL of hydrogen peroxide is injected, the injection is stopped. The solution is visually clear and free of visible impurities. After filtration, a nickel-iron-manganese metal solution and waste residue are obtained.

[0042] 25g of reduced iron powder was added to a nickel-iron-manganese metal solution. After reacting for 12 hours, a qualified nickel-iron-manganese metal solution was obtained by filtration. ICP analysis showed that the Fe content in the metal solution was [missing value]. 3+ The content is 0g / L.

[0043] Example 2: First, 200g of waste nickel-iron-manganese precursor material was placed in 400mL of pure water and thoroughly stirred and dispersed using a magnetic stirrer;

[0044] Sulfuric acid with a concentration of 7.14 mol / L is injected using a peristaltic pump (the flow rate of sulfuric acid is controlled at 5 mL / min). The reaction temperature is controlled at 60-80℃. If the reaction temperature exceeds the upper limit, the injection of sulfuric acid is stopped. The injection is resumed after the temperature drops to the required range. The injection of sulfuric acid is stopped after 600 mL of sulfuric acid has been injected.

[0045] Then, hydrogen peroxide with a concentration of 9.79 mol / L is injected through a peristaltic pump (the flow rate of hydrogen peroxide is controlled at 1 mL / min). The reaction temperature is controlled at 60-80℃. If the reaction temperature exceeds the upper limit, the injection of hydrogen peroxide is stopped. After the temperature drops to the required range, the injection is resumed. After 200 mL of hydrogen peroxide is injected, the injection is stopped. The solution is visually clear and free of visible impurities. After filtration, a nickel-iron-manganese metal solution and waste residue are obtained.

[0046] 19.5g of reduced iron powder was added to a nickel-iron-manganese metal solution. After reacting for 12 hours, a qualified nickel-iron-manganese metal solution was obtained by filtration. ICP analysis showed that the Fe content in the metal solution was [missing value]. 3+ The content is 0.001 g / L.

[0047] Example 3: First, 200g of waste nickel-iron-manganese precursor material was placed in 400mL of pure water and stirred and dispersed thoroughly using a magnetic stirrer;

[0048] Sulfuric acid with a concentration of 7.14 mol / L is injected using a peristaltic pump (the flow rate of sulfuric acid is controlled at 5 mL / min). The reaction temperature is controlled at 60-80℃. If the reaction temperature exceeds the upper limit, the injection of sulfuric acid is stopped. The injection is resumed after the temperature drops to the required range. The injection of sulfuric acid is stopped after 600 mL of sulfuric acid has been injected.

[0049] Then, hydrogen peroxide with a concentration of 9.79 mol / L is injected through a peristaltic pump (the flow rate of hydrogen peroxide is controlled at 1 mL / min). The reaction temperature is controlled at 60-80℃. If the reaction temperature exceeds the upper limit, the injection of hydrogen peroxide is stopped. After the temperature drops to the required range, the injection is resumed. After 200 mL of hydrogen peroxide is injected, the injection is stopped. The solution is visually clear and free of visible impurities. After filtration, a nickel-iron-manganese metal solution and waste residue are obtained.

[0050] 15g of reduced iron powder was added to a nickel-iron-manganese metal solution. After reacting for 12 hours, a qualified nickel-iron-manganese metal solution was obtained by filtration. ICP analysis showed that the Fe content in the metal solution was [missing value]. 3+ The content is 0.053g / L.

[0051] Comparative Example 1:

[0052] First, place 200g of waste nickel-iron-manganese precursor material in 400mL of pure water and use a magnetic stirrer to fully disperse it.

[0053] Sulfuric acid with a concentration of 7.14 mol / L is injected using a peristaltic pump (the flow rate of sulfuric acid is controlled at 5 mL / min). The reaction temperature is controlled at 60-80℃. If the reaction temperature exceeds the upper limit, the injection of sulfuric acid is stopped. The injection is resumed after the temperature drops to the required range. The injection of sulfuric acid is stopped after 600 mL of sulfuric acid has been injected.

[0054] Then, hydrogen peroxide with a concentration of 9.79 mol / L is injected through a peristaltic pump (the flow rate of hydrogen peroxide is controlled at 1 mL / min). The reaction temperature is controlled at 60-80℃. If the reaction temperature exceeds the upper limit, the injection of hydrogen peroxide is stopped. After the temperature drops to the required range, the injection is resumed. After 200 mL of hydrogen peroxide is injected, the injection is stopped. The solution is visually clear and free of visible impurities. After filtration, a nickel-iron-manganese metal solution and waste residue are obtained.

[0055] 10g of reduced iron powder was added to a nickel-iron-manganese metal solution. After reacting for 12 hours, a qualified nickel-iron-manganese metal solution was obtained by filtration. ICP analysis showed that Fe in the metal solution was... 3+ The content is 0.113 g / L.

[0056] Comparative Example 2:

[0057] First, place 200g of waste nickel-iron-manganese precursor material in 400mL of pure water and use a magnetic stirrer to fully disperse it.

[0058] Sulfuric acid with a concentration of 7.14 mol / L is injected using a peristaltic pump (the flow rate of sulfuric acid is controlled at 5 mL / min). The reaction temperature is controlled at 60-80℃. If the reaction temperature exceeds the upper limit, the injection of sulfuric acid is stopped. The injection is resumed after the temperature drops to the required range. The injection of sulfuric acid is stopped after 400 mL of sulfuric acid has been injected.

[0059] Next, hydrogen peroxide with a concentration of 9.79 mol / L is injected using a peristaltic pump (the flow rate of hydrogen peroxide is controlled at 1 mL / min). The reaction temperature is controlled at 60-80℃. If the reaction temperature exceeds the upper limit, the injection of hydrogen peroxide is stopped. After the temperature drops to the required range, the injection is resumed. After 200 mL of hydrogen peroxide is injected, the injection is stopped. The solution is visually inspected to be clear and free of visible impurities. After filtration, a nickel-iron-manganese metal solution and waste residue are obtained. The filtered nickel-iron-manganese metal solution is analyzed by ICP. The Fe content in the metal solution is... 3+ The content is 13.6 g / L.

[0060] Comparative Example 3:

[0061] First, place 200g of waste nickel-iron-manganese precursor material in 400mL of pure water and use a magnetic stirrer to fully disperse it.

[0062] Sulfuric acid with a concentration of 7.14 mol / L is injected using a peristaltic pump (the flow rate of sulfuric acid is controlled at 5 mL / min). The reaction temperature is controlled at 60-80℃. If the reaction temperature exceeds the upper limit, the injection of sulfuric acid is stopped. The injection is resumed after the temperature drops to the required range. The injection of sulfuric acid is stopped after 500 mL of sulfuric acid has been injected.

[0063] Then, hydrogen peroxide with a concentration of 9.79 mol / L is injected using a peristaltic pump (the flow rate of hydrogen peroxide is controlled at 1 mL / min). The reaction temperature is controlled at 60-80℃. If the reaction temperature exceeds the upper limit, the injection of hydrogen peroxide is stopped. After the temperature drops to the required range, the injection is resumed. After 150 mL of hydrogen peroxide is injected, the injection is stopped. The solution appears turbid and not completely dissolved. Subsequent steps are not carried out.

[0064] Comparative Example 4:

[0065] First, place 200g of waste nickel-iron-manganese precursor material in 400mL of pure water and use a magnetic stirrer to fully disperse it.

[0066] Sulfuric acid with a concentration of 7.14 mol / L is injected using a peristaltic pump (the flow rate of sulfuric acid is controlled at 5 mL / min). The reaction temperature is controlled at 60-80℃. If the reaction temperature exceeds the upper limit, the injection of sulfuric acid is stopped. The injection is resumed after the temperature drops to the required range. The injection of sulfuric acid is stopped after 600 mL of sulfuric acid has been injected.

[0067] Then, hydrogen peroxide with a concentration of 9.79 mol / L is injected using a peristaltic pump (the flow rate of hydrogen peroxide is controlled at 1 mL / min). The reaction temperature is controlled at 60-80℃. If the reaction temperature exceeds the upper limit, the injection of hydrogen peroxide is stopped. After the temperature drops to the required range, the injection is resumed. After 100 mL of hydrogen peroxide is injected, the injection is stopped. The solution appears turbid and not completely dissolved. Subsequent steps are not carried out.

[0068] The main difference between Comparative Example 1 and Example 1 is that the amount of reducing agent iron powder added is significantly reduced. Under the same dissolution process conditions, the nickel-iron-manganese metal solution obtained in Comparative Example 1 is clear and free of visible impurities. However, upon testing, Fe in the solution... 3+ The concentration was 0.113 g / L, which failed to meet the standard specified in the process (Fe). 3+ ≤0.06g / L).

[0069] A comparison of the test results of each embodiment and comparative example shows (see Table 1) that the "clear and impurity-free" appearance of the solution is ensured by sufficient sulfuric acid (600 mL) and hydrogen peroxide (200 mL), while Fe... 3+ The concentration requirement (≤0.06 g / L) was controlled by a sufficient amount of reduced iron powder (>15 g / L). In summary, the process parameters of Example 1 (25 g / L iron powder) and Example 2 (19.5 g / L iron powder) ensured that the solution parameters met the requirements for reuse. Furthermore, in Example 2, under the process condition of an iron powder dosage of 19.5 g / L, the Fe content in the obtained nickel-iron-manganese metal solution... 3+ The concentration can be stably controlled below 0.06 g / L, meeting the process specifications (Fe). 3+ (≤0.06g / L), demonstrating good economic efficiency and practical value.

[0070] Table 1 Comparison of different addition amounts

[0071]

[0072] Example 1 (600mL sulfuric acid + 200mL hydrogen peroxide + 25g iron powder) The reaction system was clear and free of impurities, and Fe 3+ A concentration of 0 indicates that when iron powder is in sufficient quantity, Fe... 3+ Completely reduced to Fe 2+ The solution showed no precipitate or turbidity.

[0073] Example 2 (19.5g iron powder) Fe 3+ The concentration was 0.001 g / L. Example 3 (15 g of iron powder) Fe 3+ The concentration increased to 0.053 g / L, indicating that the amount of iron powder added directly affected the Fe concentration. 3+ Residual amount, Fe can be achieved when iron powder ≥15g / L. 3+ Almost completely removed, while in Comparative Example 2, without added iron powder, although the solution was clear, Fe... 3+ The concentration was as high as 13.6 g / L, indicating that Fe under conditions without reducing agent... 3+ Unable to be reduced, it remains in the system. Therefore, by optimizing the ratio of sulfuric acid, hydrogen peroxide, and iron powder, and utilizing the reducing properties of iron powder in an acidic environment, the residual Fe can be removed. 3+ Efficient reduction to Fe 2+ To avoid precipitation.

[0074] Comparative Example 2 confirms that Fe is present without iron powder. 3+ A large amount of residue remained, and comparative examples 3-4 showed that an imbalance in the reactant ratio would lead to turbidity, further highlighting the effectiveness of the formulation of this invention (as in Example 2) in achieving solution clarification and thorough removal of Fe. 3+ The necessity of this aspect.

[0075] In Comparative Examples 3-4, if the amount of sulfuric acid or hydrogen peroxide is insufficient, the solution will be cloudy and contain impurities. This may be due to the precipitation of intermediate products or the presence of undissolved solid residues caused by insufficient reactants.

[0076] Therefore, Example 2 embodies the core technical points of the present invention—by optimizing the material ratio and utilizing the reducing properties of iron powder, Fe³⁺ is removed most efficiently and thoroughly, and a clear solution is obtained.

[0077] In summary, this invention, through precise control of the dosage of each component, has the beneficial effects of thorough reaction, pure product, and no impurity residue.

[0078] This invention successfully achieves the goal of efficient recovery of valuable metal resources from waste nickel-iron-manganese precursor materials. The method ultimately produces a mixed solution of nickel sulfate, ferrous sulfate, and manganese sulfate, which can be precisely formulated to the target stoichiometric ratio according to product requirements, thus allowing it to be directly used as a qualified raw material in the production of cathode material precursors. This method has significant advantages such as short process, simple operation, and low recycling cost, providing clear economic benefits for material recycling and possessing excellent prospects for industrial application.

[0079] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A method for recovering valuable metals from waste nickel-iron-manganese precursors, characterized in that: include: Step 1: Disperse the waste nickel-iron-manganese precursor material in pure water to obtain a first mixture. The mass ratio of the waste nickel-iron-manganese precursor material to pure water in the first mixture is controlled at (0.4~0.6):

1. Step 2: Add the acid solution to the first mixture, utilizing the reaction between the acid solution and the OH- in the waste nickel-iron-manganese precursor. - The reaction disrupts its layered structure, releasing metal ions containing nickel, iron, and manganese, resulting in a second mixture. Step 3: Add the oxidant solution to the second mixture to oxidize the low-valence metal ions to high-valence states, improving the dissolution efficiency. Then filter out the solid impurities to obtain the third mixture. At this point, the third mixture contains nickel, iron, and manganese metal ions, wherein the iron ions are oxidized to Fe... 2+ It turned into Fe 3+ ; Step 4: Add the reducing agent to the third mixture, using the reducing agent to remove Fe from the third mixture. 3+ Reduced to Fe 2+ After filtration, a nickel-iron-manganese metal solution is obtained.

2. The method for recovering valuable metals from waste nickel-iron-manganese precursors according to claim 1, characterized in that: The acid solution is added at a rate of 2-10 mL / min, and the liquid-solid ratio of the acid solution added to the waste nickel-iron-manganese precursor material is 1-5 mL / g.

3. The method for recovering valuable metals from waste nickel-iron-manganese precursors according to claim 1, characterized in that: In step one, the liquid-to-solid ratio of water to waste nickel-iron-manganese ternary precursor material is 1~5 mL / g.

4. The method for recovering valuable metals from waste nickel-iron-manganese precursors according to claim 1, characterized in that: In step two, the reaction conditions include: pH value of 0.2-3, temperature of 60-80℃, and time of 1-4h.

5. A method for recovering valuable metals from waste nickel-iron-manganese precursors according to claim 1 or 2, characterized in that: In step three, the oxidant solution is added at a rate of 1-5 mL / min, and the reaction conditions include: pH value of 0.2-3, temperature of 60-80℃, time of 2-6 h, liquid-solid ratio of oxidant solution to waste nickel-iron-manganese precursor material of 1-3 mL / g, and no visible impurities in the clear liquid of the third mixture before filtration.

6. A method for recovering valuable metals from waste nickel-iron-manganese precursors according to claim 1 or 2, characterized in that: In step four, the amount of reducing agent added is controlled at 10~30g / L.

7. A method for recovering valuable metals from waste nickel-iron-manganese precursors according to claim 1 or 2, characterized in that: The acid solution is selected from at least one of hydrochloric acid solution, sulfuric acid solution, nitric acid solution, and phosphoric acid solution; The concentration of the acid solution is 2~10 mol / L.

8. A method for recovering valuable metals from waste nickel-iron-manganese precursors according to claim 1 or 2, characterized in that: The reducing agent is selected from at least one of iron powder, oxalic acid, and zinc powder.

9. A method for recovering valuable metals from waste nickel-iron-manganese precursors according to claim 1 or 2, characterized in that: The oxidant solution is selected from at least one of hydrogen peroxide solution, sodium persulfate solution, and sodium chlorate solution.

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