A method for short-range recovery of valuable metals from waste ternary lithium batteries

Abstract

The application discloses a method for short-range recovery of valuable metals from waste ternary lithium batteries, which comprises the steps of precipitating nickel and cobalt by a two-stage chemical precipitation method, precipitating lithium by combined phosphoric acid trisodium, and the like, overcomes the problem of high impurity content of lithium carbonate in the prior art, and obtains high-quality lithium carbonate, and the whole process is carried out in an atmospheric environment; compared with a complex process of recovering nickel, cobalt and manganese metals by using extraction + MVR evaporation crystallization and recovering lithium metal by MVR concentration, the energy consumption requirement of the waste ternary lithium battery recovery process and the environmental pollution are greatly reduced, and the industrial production is facilitated.

Description

Technical Field

[0001] This article relates to the field of lithium battery recycling technology, specifically to a method for short-range recovery of valuable metals from waste ternary lithium batteries. Background Technology

[0002] Since entering the market in 1992, lithium-ion batteries have been widely used in electronic information products, such as power banks for cameras, mobile phones, and laptops. Lithium-ion batteries are excellent rechargeable batteries with advantages such as high operating voltage, large specific capacity, long cycle life, and good safety performance. They are typically composed of a positive electrode, a negative electrode, a separator, an electrolyte, and a binder. During operation, lithium ions are inserted and extracted at the positive and negative electrodes. During charging, lithium ions are extracted from the positive electrode and move to the negative electrode through the electrolyte. The released electrons are transferred from the outside to the negative electrode to maintain charge balance. At this time, cobalt ions are oxidized, and the positive electrode is in a lithium-deficient state. During discharging, the opposite occurs: lithium ions are extracted and move towards the positive electrode, cobalt ions are reduced, and the negative electrode is in a lithium-deficient state. With the widespread use of lithium-ion batteries, a large number of waste lithium-ion batteries have been generated. These waste lithium-ion batteries contain a large amount of valuable metals and toxic chemicals. Landfilling them as municipal waste causes environmental pollution and wastes resources.

[0003] During the cyclic charging and discharging process of lithium-ion batteries, the battery capacity gradually decreases. Generally, when the battery capacity drops to 70-80%, it is considered that the battery can be retired. In industry, the recycling of waste lithium-ion power batteries is mainly divided into two cycles: secondary use and recycling. Among them, lithium iron phosphate batteries are mainly used for secondary use due to their better cycle performance, while ternary lithium batteries, which contain valuable metals such as lithium, nickel, and cobalt, are mainly used for recycling.

[0004] Waste batteries possess the dual attributes of environmental pollution and metal resource utilization. If waste lithium-ion batteries can be disposed of harmlessly and recyclably, it can not only avoid the environmental pollution they cause but also alleviate the pressure on related metal resources and promote the steady development of the new energy industry.

[0005] Existing technologies include a large amount of research on the recovery of valuable metals from waste ternary lithium batteries. CN116121544A uses an extractant to recover some metals, but the wastewater output is large and the energy consumption of wastewater treatment is high, which is not conducive to industrial production.

[0006] Therefore, this article is presented. Summary of the Invention

[0007] The purpose of this paper is to provide a method for short-range recovery of valuable metals from waste ternary lithium batteries, thereby improving the metal recovery rate and realizing the comprehensive utilization of waste batteries.

[0008] This article implements it as follows:

[0009] Firstly, this paper provides a method for short-range recovery of valuable metals from spent ternary lithium batteries, including:

[0010] The process involves sequentially performing a first-stage and a second-stage nickel-cobalt-manganese precipitation process on the iron-aluminum-removed liquid, followed by solid-liquid separation to obtain nickel-cobalt-manganese hydroxide and a post-precipitation liquid. The pH value in the first-stage nickel-cobalt-manganese precipitation step is 8-9, and the pH value in the second-stage step is 10-11. The post-precipitation liquid is obtained from battery black powder through sequential pyrolysis, a first-stage reduction leaching, copper removal, and iron-aluminum removal.

[0011] Lithium precipitation with trisodium phosphate: Trisodium phosphate is used to precipitate lithium from the solution after nickel, cobalt, and manganese precipitation. Solid-liquid separation is then performed to obtain a lithium phosphate intermediate and a sodium salt solution.

[0012] Lithium phosphate leaching: Iron salt and a first acid solution are added to the slurry of the lithium phosphate intermediate for leaching, followed by solid-liquid separation to obtain iron phosphate slag and lithium salt solution.

[0013] Lithium carbonate is precipitated by adding carbonate to the lithium salt solution and then separating the solid and liquid phases to obtain lithium carbonate.

[0014] In some embodiments, a first acid solution is added to the nickel-cobalt-manganese precipitate solution to adjust the pH value to 8.0-8.5, and then trisodium phosphate is added to precipitate lithium. The mass of trisodium phosphate added is 1.05-1.15 times the theoretical amount.

[0015] In some embodiments, the first acid solution is sulfuric acid or hydrochloric acid.

[0016] In some embodiments, the slurry of the lithium phosphate intermediate is obtained by first pulping lithium phosphate and water at a solid-liquid ratio of 1:(3-4).

[0017] In some embodiments, in the lithium phosphate leaching step, the iron salt is ferric sulfate, and the molar ratio of lithium phosphate to ferric sulfate is (2.3-2.7):1.

[0018] In some embodiments, during the lithium phosphate leaching step, the first acid solution is sulfuric acid, which is used to adjust the pH of the solution to 2.5-3.5. In some embodiments, during the lithium carbonate precipitation step, the reaction temperature is 80℃-85℃, and the reaction time is greater than 2 hours.

[0019] In some embodiments, in the step of precipitating lithium carbonate, the pH of the solution is first adjusted to 10.5-11.5, and then water-soluble carbonate is added, with the mass of the added water-soluble carbonate being 1.1-1.3 times the theoretical amount.

[0020] In some embodiments, the battery black powder is obtained by immersing a ternary lithium battery in salt water for discharge, and then crushing and sieving the discharged ternary lithium battery.

[0021] In some implementations, the temperature for pyrolyzing the battery black powder is 400℃-600℃, and the pyrolysis time is 1h-3h.

[0022] In some embodiments, the first-stage reduction leaching involves adding water to the pyrolyzed battery black powder for a second slurrying, then adjusting the pH value to 1-2 using a second acid solution, and introducing a first reducing agent into the slurry for reduction leaching. After leaching is completed, solid-liquid separation is performed to obtain acid leaching residue and reduction leaching solution.

[0023] In some embodiments, the solid-liquid ratio of battery black powder to water in the slurry obtained in the second slurrying step is 1:(3-4).

[0024] In some embodiments, the second acid is sulfuric acid or hydrochloric acid.

[0025] In some embodiments, the first reducing agent is sodium metabisulfite or sulfur dioxide, and the amount of the first reducing agent added is the sum of 0.5-1 times the molar amount of trivalent cobalt and 1-1.5 times the molar amount of trivalent manganese in the black powder.

[0026] In some implementations, the duration of a reduction leaching step is 1-2 hours.

[0027] In some implementations, it also includes:

[0028] In the second-stage high-acid leaching, the acid leaching residue is mixed with water for a third pulping, followed by the addition of a third acid solution for high-acid leaching. After leaching, solid-liquid separation is performed to obtain the second-stage high-acid leaching residue and the second-stage high-acid leaching solution.

[0029] The high-acid leaching residue is washed and filtered to obtain high-acid leaching residue containing carbon powder.

[0030] In some embodiments, the second-stage high-acid leachate is returned to a first-stage reductive leaching step for mixing and pulping with black powder.

[0031] In some embodiments, in the third pulping step, the acid leaching residue and water are pulped at a solid-liquid ratio of 1:(3-4).

[0032] In some embodiments, the third acid solution is sulfuric acid or hydrochloric acid.

[0033] In some embodiments, during the two-stage high-acid leaching step, a third acid solution is added to adjust the hydrogen ion equivalent of the slurry to 4N.

[0034] In some implementations, the high acid leaching time is 1-2 hours.

[0035] In some embodiments, the copper removal step includes adding a second reducing agent to the reducing leaching solution to carry out a copper removal reaction, and after the copper removal reaction is completed, performing solid-liquid separation to obtain sponge copper and copper-removed liquid.

[0036] In some embodiments, the second reducing agent is iron powder, and the mass of the iron powder added is 1.05-1.15 times the theoretical amount.

[0037] In some embodiments, the reducing leaching solution is further filtered twice, and the separated liquid phase enters the copper removal step, while the solid phase is mixed with the acid leaching residue for high-acid leaching.

[0038] In some embodiments, the iron and aluminum removal step includes adding an oxidant to the copper-removed liquid to carry out an iron and aluminum removal reaction, and performing solid-liquid separation after the iron and aluminum removal reaction is completed to obtain iron and aluminum slag and iron and aluminum-removed liquid.

[0039] In some embodiments, the oxidant is hydrogen peroxide, and the amount of hydrogen peroxide added is 0.5-1 times the molar amount of divalent iron in the copper-removed solution.

[0040] In some embodiments, after the iron and aluminum removal reaction is completed, the pH value is adjusted to 4.5-5.0 and maintained for 30-60 minutes before solid-liquid separation is performed.

[0041] In some implementations...

[0042] The first-stage nickel-cobalt-manganese precipitation step includes adding alkaline solution to the iron and aluminum removal liquid to adjust the pH value to 8-9 and maintaining it for 60-90 minutes, then performing solid-liquid separation to obtain refined nickel-cobalt-manganese hydroxide product and the first-stage nickel-cobalt-manganese precipitation liquid.

[0043] The two-stage nickel-cobalt-manganese precipitation step includes adding alkali solution to the post-precipitation solution of the first-stage nickel-cobalt-manganese precipitation to adjust the pH value to 10-11 and maintaining it for 60-90 minutes, followed by solid-liquid separation to obtain crude nickel-cobalt-manganese hydroxide product and post-precipitation solution.

[0044] In some embodiments, the alkaline solution is an aqueous solution of a strong base.

[0045] This article has the following beneficial effects:

[0046] This method uses a two-stage chemical precipitation process to preliminarily classify the obtained nickel cobalt manganese hydroxide product. The first stage, with a pH of 8-9, precipitates a nickel cobalt manganese hydroxide product with relatively high purity. The second stage adjusts the pH to 10-11, precipitating a nickel cobalt manganese hydroxide product with relatively higher impurity content. The method is simple to operate, has low production costs, and high recovery rates. At the same time, it generates very little wastewater, reducing wastewater treatment costs and improving production efficiency.

[0047] This method first precipitates lithium using trisodium phosphate, then leaches and converts it using iron salts and a first acid solution to obtain a high-concentration lithium-containing solution. Finally, it precipitates lithium using sodium carbonate to obtain a lithium carbonate product with a high lithium content, achieving efficient lithium recovery. This provides a short and efficient wet recovery method for lithium, overcoming the problem of high impurity content in lithium carbonate in existing technologies, and obtaining higher quality lithium carbonate. Moreover, the entire process is carried out under normal pressure, which is conducive to industrial production.

[0048] Compared to traditional wet recycling technology for spent ternary lithium batteries, this solution has advantages such as a shorter process flow and lower production costs. It eliminates the complex process of using extraction + MVR evaporation crystallization to recover nickel, cobalt, and manganese metals and then using MVR concentration to recover lithium metals, which greatly reduces the energy consumption and environmental pollution of the spent ternary lithium battery recycling process. Attached Figure Description

[0049] To more clearly illustrate the technical solutions of the embodiments in this paper, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this paper and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0050] Figure 1 This is the flowchart for this article;

[0051] Figure 2 This is a flowchart of an embodiment in this article. Detailed Implementation

[0052] To make the objectives, technical solutions, and advantages of the embodiments described herein clearer, the technical solutions in the embodiments will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0053] This embodiment provides a method for short-range recovery of valuable metals from spent ternary lithium batteries. Figure 1 As shown, it includes:

[0054] The process involves sequentially performing a first-stage and a second-stage nickel-cobalt-manganese precipitation process on the iron-aluminum-removed liquid, followed by solid-liquid separation to obtain nickel-cobalt-manganese hydroxide and a post-precipitation liquid. The pH value in the first-stage nickel-cobalt-manganese precipitation step is 8-9, and the pH value in the second-stage step is 10-11. The post-precipitation liquid is obtained from battery black powder through sequential pyrolysis, a first-stage reduction leaching, copper removal, and iron-aluminum removal.

[0055] Lithium precipitation with trisodium phosphate: Trisodium phosphate is used to precipitate lithium from the solution after nickel, cobalt, and manganese precipitation. Solid-liquid separation is then performed to obtain a lithium phosphate intermediate and a sodium salt solution.

[0056] Lithium phosphate leaching: Iron salt and a first acid solution are added to the slurry of the lithium phosphate intermediate for leaching, followed by solid-liquid separation to obtain iron phosphate slag and lithium salt solution.

[0057] Lithium carbonate is precipitated by adding carbonate to the lithium salt solution, followed by solid-liquid separation to obtain lithium carbonate.

[0058] This method employs a two-stage chemical precipitation process to preliminarily classify the obtained nickel-cobalt-manganese hydroxide product. The first stage, with a pH of 8-9, precipitates a nickel-cobalt-manganese hydroxide product with relatively high purity. The second stage adjusts the pH to 10-11, precipitating a nickel-cobalt-manganese hydroxide product with a relatively higher impurity content. This method is characterized by its simple operation, low production cost, and high recovery rate. Simultaneously, it generates minimal wastewater, reducing wastewater treatment costs and improving production efficiency. Compared to a one-stage precipitation method, the two-stage chemical precipitation method offers advantages in overall recovery rate and quality of the nickel-cobalt-manganese hydroxide product, and also contributes to improving the subsequent recovery rate of lithium metal and the quality of lithium carbonate products.

[0059] This method first precipitates lithium using trisodium phosphate, then leaches and converts it using iron salts and a first acid solution to obtain a high-concentration lithium-containing solution. Finally, it precipitates lithium again using sodium carbonate, yielding a high-content lithium carbonate product. This achieves efficient lithium recovery and provides a concise and efficient wet lithium recovery method. It overcomes the problem of high impurity content in lithium carbonate found in existing technologies, obtaining higher-quality lithium carbonate. Furthermore, the entire process is conducted under normal pressure, which is beneficial for industrial production. The use of trisodium phosphate precipitation increases the sodium ion concentration in the solution. When the sodium ion concentration reaches a certain level, it promotes lithium precipitation, thereby improving the recovery rate and quality of lithium carbonate.

[0060] In this scheme, in order to provide a high sodium environment for the precipitation of lithium carbonate, sodium ions can be selected as much as possible as the required cations when recovering other metals. At the same time, in order to reduce the difficulty of treating the discharged wastewater and facilitate recovery or treatment, sulfate ions can be selected as much as possible as the anions, which can easily generate sodium sulfate solution for reuse and have a relatively small impact on the environment.

[0061] Compared to traditional wet recycling technology for spent ternary lithium batteries, this solution has advantages such as a shorter process flow and lower production costs. It eliminates the complex process of using extraction + MVR evaporation crystallization to recover nickel, cobalt, and manganese metals and then using MVR concentration to recover lithium metals, which greatly reduces the energy consumption and environmental pollution of the spent ternary lithium battery recycling process.

[0062] In some embodiments, a first acid solution is added to the nickel-cobalt-manganese precipitate solution to adjust the pH value to 8.0-8.5, and then trisodium phosphate is added to precipitate lithium. The mass of trisodium phosphate added is 1.05-1.15 times the theoretical amount.

[0063] Adding a slightly excessive amount of trisodium phosphate is beneficial for the more complete precipitation of lithium ions. Specifically, in this scheme, the pH value can be adjusted to any value between 8.0, 8.1, 8.2, 8.3, 8.4, 8.5 or 8.0-8.5, and the mass of trisodium phosphate added can be any value between 1.05 times, 1.1 times, 1.15 times or 1.05-1.15 times the theoretical amount.

[0064] In some embodiments, the first acid solution is sulfuric acid or hydrochloric acid, with sulfuric acid being beneficial for the recovery and utilization of subsequent products.

[0065] In some embodiments, the slurry of the lithium phosphate intermediate is obtained by first pulping lithium phosphate and water at a solid-liquid ratio (mass ratio, all subsequent solid-liquid ratios are solid-liquid mass ratios) of 1:(3-4).

[0066] In some embodiments, in the lithium phosphate leaching step, the iron salt is ferric sulfate, and the molar ratio of lithium phosphate to ferric sulfate is (2.3-2.7):1.

[0067] In some embodiments, in the lithium phosphate leaching step, the first acid solution is sulfuric acid, which is used to adjust the pH of the solution to 2.5-3.5. In some embodiments, in the lithium carbonate precipitation step, the reaction temperature is 80℃-85℃, specifically any value between 80℃, 81℃, 82℃, 83℃, 84℃, 85℃, or 80℃-85℃; the reaction time is greater than 3 hours, and the reaction is usually stopped when the precipitate no longer forms or the formation rate falls below a preset standard.

[0068] In some embodiments, in the step of precipitating lithium carbonate, the pH of the solution is first adjusted to 10.5-11.5, and then a water-soluble carbonate is added. Specifically, the pH of the solution can be adjusted to any value between 10.5, 10.7, 10.9, 11.1, 11.3, 11.5, or 10.5-11.5. The water-soluble carbonate can be sodium carbonate, potassium carbonate, etc. The mass of the water-soluble carbonate added is 1.1-1.3 times the theoretical amount, specifically, it can be any value between 1.1 times, 1.15 times, 1.2 times, 1.25 times, 1.3 times, or 1.1-1.3 times.

[0069] In some embodiments, the battery black powder is obtained by immersing a ternary lithium battery in salt water for discharge, and then crushing and sieving the discharged ternary lithium battery.

[0070] In this embodiment, the composition of the battery black powder varies depending on the type of ternary lithium battery, but all of them are applicable to this embodiment.

[0071] During discharge, used ternary lithium batteries can be discharged using sodium carbonate or sodium chloride saline solution, and the discharge time is generally greater than 2 hours.

[0072] In some embodiments, the temperature for pyrolyzing the battery black powder is 400℃-600℃, specifically any value between 400℃, 450℃, 500℃, 550℃, 600℃ or 400℃-600℃; the pyrolysis time is 1h-3h, specifically any value between 1h, 1.5h, 2h, 2.5h, 3h or 1h-3h. Pyrolysis can remove electrolyte and separator substances from the battery black powder.

[0073] In some embodiments, the first-stage reduction leaching involves adding water to the pyrolyzed battery black powder for a second slurrying, then adjusting the pH value to 1-2 using a second acid solution, and introducing a first reducing agent into the slurry for reduction leaching. After leaching, solid-liquid separation is performed to obtain acid leaching residue and reduction leaching solution. The metal elements to be recovered are dissolved in the reduction leaching solution for further utilization.

[0074] In some embodiments, the solid-liquid ratio of battery black powder to water in the slurry obtained in the second slurrying step is 1:(3-4), specifically any value between 1:3.2, 1:3.4, 1:3.6, 1:3.8, 1:4.0 or 1:(3-4), to extract undissolved metal elements. If the solid-liquid ratio of battery black powder to water is too low, the metal dissolution rate will be reduced. If the solid-liquid ratio is too high, the content of target ions in the system will be low. During the later precipitation process, the recovery rate will be reduced due to some solution remaining in the solution, and the amount of wastewater generated will increase, thereby increasing the environmental impact.

[0075] In some embodiments, the second acid is sulfuric acid or hydrochloric acid, preferably sulfuric acid.

[0076] In some embodiments, the first reducing agent is sodium metabisulfite or sulfur dioxide, and the amount of the first reducing agent added is the sum of 0.5-1 times the molar amount of trivalent cobalt and 1-1.5 times the molar amount of trivalent manganese in the black powder. In some embodiments, the duration of a reduction leaching step is 1-2 hours, specifically any value between 1 hour, 1.5 hours, 2 hours, or 1-2 hours.

[0077] In some implementations, it also includes:

[0078] In the second-stage high-acid leaching, the acid leaching residue is mixed with water for a third pulping, followed by the addition of a third acid solution for high-acid leaching. After leaching, solid-liquid separation is performed to obtain the second-stage high-acid leaching residue and the second-stage high-acid leaching solution.

[0079] The high-acid leaching residue is washed and filtered to obtain high-acid leaching residue containing carbon powder.

[0080] This embodiment employs high-acid leaching and washes the high-acid leaching residue as needed to further improve the leaching rate of the target elements, while also increasing the carbon content in the acid leaching residue.

[0081] In some embodiments, the second-stage high-acid leachate is returned to the first-stage reduction leaching step for mixing and pulping with black powder, and the washing liquid obtained from washing the high-acid leachate residue can also be returned to the first-stage reduction leaching step for mixing and pulping with black powder, thereby reducing the loss of target elements.

[0082] In some embodiments, during the third pulping step, the acid leaching residue and water are pulped at a solid-liquid ratio of 1:(3-4). In some embodiments, the third acid solution is sulfuric acid or hydrochloric acid, with sulfuric acid being more beneficial for subsequent wastewater treatment.

[0083] In some embodiments, during the two-stage high-acid leaching step, a third acid solution is added to adjust the hydrogen ion equivalent of the slurry to 4N.

[0084] In some implementations, the high acid leaching time is 1-2 hours, specifically any value between 1 hour, 1.5 hours, 2 hours, or 1-2 hours.

[0085] In some embodiments, the copper removal step includes adding a second reducing agent to the reducing leaching solution to carry out a copper removal reaction, and after the copper removal reaction is completed, performing solid-liquid separation to obtain sponge copper and copper-removed liquid.

[0086] In some embodiments, the second reducing agent is iron powder, and the mass of the iron powder added is 1.05-1.15 times the theoretical amount, specifically any value between 1.05 times, 1.1 times, 1.15 times, or 1.05-1.15 times. Using iron powder as a reducing agent does not introduce elements that are not present in the system, making it convenient to remove them in the subsequent iron and aluminum removal steps.

[0087] In some embodiments, the reducing leaching solution is further filtered twice, and the separated liquid phase enters the copper removal step. The solid phase is mixed with the acid leaching residue for high acid leaching. The secondary filtration further separates the copper slag with smaller particle size in the liquid phase, thereby improving the copper recovery rate.

[0088] In some embodiments, the iron and aluminum removal step includes adding an oxidant to the copper-removed liquid to carry out an iron and aluminum removal reaction, and performing solid-liquid separation after the iron and aluminum removal reaction is completed to obtain iron and aluminum slag and iron and aluminum-removed liquid.

[0089] In some embodiments, the oxidant is hydrogen peroxide, and the amount of hydrogen peroxide added is 0.5-1.0 times the molar amount of divalent iron in the copper-removed solution. The hydrogen peroxide is reduced to water and no new impurities are introduced.

[0090] In some embodiments, after the iron and aluminum removal reaction is completed, the pH value is adjusted to 4.5-5.0 and maintained for 30-60 minutes before solid-liquid separation is performed.

[0091] Specifically, in this embodiment, the pH value can be adjusted to any value between 4.5, 4.6, 4.7, 4.8, 4.9, 5.0, or 4.5-5.0; the holding time can be adjusted to any value between 30 min, 40 min, 50 min, 60 min, or 30 min-60 min. After adjusting the pH value, maintain it for a period of time to allow the iron and aluminum to fully precipitate before solid-liquid separation. Rapid stirring should be avoided as much as possible during pH maintenance.

[0092] In some implementations...

[0093] The first-stage nickel-cobalt-manganese precipitation step includes adding an alkaline solution to the iron-aluminum-removed liquid to adjust the pH value to 8-9, maintaining it for 60-90 minutes, and then performing solid-liquid separation to obtain a refined nickel-cobalt-manganese hydroxide product and a first-stage nickel-cobalt-manganese precipitation liquid. Specifically, the pH value can be adjusted to any value between 8.0, 8.2, 8.4, 8.6, 8.8, 9.0, or 8-9; the maintenance time can be adjusted to any value between 60 minutes, 70 minutes, 80 minutes, 90 minutes, or 60-90 minutes.

[0094] The two-stage nickel-cobalt-manganese precipitation step includes adding alkali solution to the post-precipitation solution of the first-stage nickel-cobalt-manganese precipitation to adjust the pH value to 10-11, maintaining it for 60-90 minutes, and then performing solid-liquid separation to obtain crude nickel-cobalt-manganese hydroxide product and post-precipitation solution. Specifically, the pH value can be adjusted to any value between 10.0, 10.2, 10.4, 10.6, 10.8, 11.0 or 8-9; the maintenance time can be adjusted to any value between 60 minutes, 70 minutes, 80 minutes, 90 minutes or 60-90 minutes.

[0095] In some embodiments, the alkaline solution is an aqueous solution of a strong alkali. In this embodiment, sodium hydroxide can be selected to facilitate wastewater treatment and the subsequent precipitation of lithium carbonate.

[0096] It should be noted that the main purpose of the acids and bases in this article is to adjust the pH value, so the concentration has little effect on the system. Higher concentration solutions or lower concentration solutions can be selected. Some liquid acids, such as hydrochloric acid, can also be used directly without dilution, but actual conditions need to be considered to avoid safety accidents.

[0097] In this paper, each solid-liquid separation step can adopt conventional solid-liquid separation methods, such as pressure filtration. The solid residue obtained from each solid-liquid separation step can also be washed before entering the next process. The washing liquid can be returned to the previous step for reuse. Specifically, the solid residue can be washed by pulping and then pressure filtration, or by CCD countercurrent washing and then pressure filtration.

[0098] The features and performance of this document are further described in detail below with reference to embodiments.

[0099] Example 1

[0100] A method for short-range recovery of valuable metals from spent ternary lithium batteries, the specific process is as follows: Figure 2 As shown, it includes:

[0101] (1) The waste ternary lithium batteries were immersed in sodium chloride solution for discharge treatment for 2 hours. After discharge, they were crushed, screened and roasted at 400℃ for 1 hour. The mass fraction of each component of the battery black powder obtained after pretreatment was: 7.0% Co, 0.2% Cu, 15% Ni, 0.5% Fe, 3.0% Al, 8.0% Mn, 0.3% Ca, 0.3% Mg, 0.1% Zn, 0.002% Pb, 0.001% Cd, 0.001% Cr and 2.5% Li.

[0102] (2) Battery black powder and water were mixed and slurried at a solid-liquid ratio of 1:3. Sulfuric acid was added to adjust the pH to 1.0. Simultaneously, sulfur dioxide was introduced during the reaction for a first-stage reductive leaching. The amount of sulfur dioxide used was the sum of 0.5 times the molar amount of trivalent cobalt and 1 times the molar amount of trivalent manganese in the battery black powder. The reaction time was 1 hour. After the reaction was completed, solid-liquid separation was performed to obtain a first-stage reductive leaching solution and acid leaching residue. The first-stage reductive leaching solution was further subjected to precision filtration to obtain a first-stage fine leaching solution. The acid... The leaching residue is mixed with water and slurryed. The acid leaching residue and water are mixed at a solid-liquid ratio of 1:3, and sulfuric acid is added for high acid leaching. The pH of the slurry is adjusted to 0.5. After reacting for 1.5 hours, solid-liquid separation is performed to obtain a second-stage high acid leaching solution and a second-stage high acid leaching residue. The second-stage high acid leaching solution is returned to the first-stage leaching process to slurry with battery black powder. The second-stage high acid leaching residue is washed to obtain qualified second-stage high acid leaching residue. The high acid leaching residue is then packaged. The main component of the high acid leaching residue is carbon powder.

[0103] (3) Add iron powder to the first-stage leaching filtrate to remove copper. The mass of iron powder added is 1.05 times the theoretical amount (the theoretical amount of copper reduction). Displacement is carried out at room temperature for 40 minutes. After the reaction is completed, solid-liquid separation is performed to obtain sponge copper and copper-removed liquid. Hydrogen peroxide is added dropwise to the copper-removed liquid. The amount of hydrogen peroxide is 0.5 times the molar amount of divalent iron in the copper-removed liquid. After the hydrogen peroxide is added dropwise, sodium carbonate solution is added to adjust the pH value to 4.5. The reaction is maintained at this pH value for 0.5 hours. Solid-liquid separation is then performed to obtain iron-aluminum-removed liquid and iron-aluminum slag. The iron-aluminum slag is subjected to three-stage pressure filtration and CCD washing. After washing, qualified iron-aluminum slag is obtained. The iron-aluminum slag is then packaged.

[0104] (4) After removing iron and aluminum, add sodium hydroxide solution to adjust the pH value to 8.0 and maintain this pH value for 1 hour. After the reaction is completed, perform solid-liquid separation to obtain nickel cobalt manganese hydroxide product and a first-stage nickel cobalt manganese precipitation liquid. Add sodium hydroxide solution to the first-stage nickel cobalt manganese precipitation liquid to adjust the pH value to 10.0 and maintain this pH value for 1 hour. After the reaction is completed, perform solid-liquid separation to obtain crude nickel cobalt manganese hydroxide and a second-stage nickel cobalt manganese precipitation liquid. The crude nickel cobalt manganese hydroxide can be returned to the first-stage reduction leaching process for recycling after being slurried with water.

[0105] (5) After the second stage of nickel, cobalt and manganese precipitation, sulfuric acid was added dropwise to adjust the pH value to 8.0. Trisodium phosphate was added to carry out the lithium precipitation reaction. The mass of trisodium phosphate added was 1.05 times the theoretical amount (the theoretical amount of lithium precipitation). After the reaction was complete, solid-liquid separation was carried out to obtain lithium phosphate intermediate and sodium sulfate solution. The lithium phosphate intermediate was mixed with water at a solid-liquid ratio of 1:3 for pulping treatment. Ferric sulfate and sulfuric acid were added for leaching. The molar ratio of lithium phosphate to ferric sulfate was 2.5:1. At the same time, sulfuric acid was added to adjust the pH value of the solution to 2.5, and lithium was dissolved in the solution to obtain a high concentration of lithium sulfate solution.

[0106] (6) The lithium sulfate solution is heated to 80°C, and sodium carbonate solution is added to precipitate lithium. The amount of sodium carbonate used is 1.2 times the theoretical amount. At the same time, the pH value of the solution is maintained at 10.5. The reaction time is 3h. After the reaction is completed, solid-liquid separation is performed to obtain the lithium carbonate product.

[0107] Example 2:

[0108] A method for short-range recovery of valuable metals from spent ternary lithium batteries includes:

[0109] (1) Waste ternary lithium batteries were discharged in sodium chloride solution for 3 hours. After discharge, they were crushed, screened and roasted at 500°C for 1.5 hours. The contents of each component of the battery black powder obtained after pretreatment were: 7.0% Co, 0.2% Cu, 15% Ni, 0.5% Fe, 3.0% Al, 8.0% Mn, 0.3% Ca, 0.3% Mg, 0.1% Zn, 0.002% Pb, 0.001% Cd, 0.001% Cr and 2.5% Li.

[0110] (2) Battery black powder and water were mixed and slurried at a solid-liquid ratio of 1:3.5. Sulfuric acid was added to adjust the pH to 2.0. At the same time, sulfur dioxide was introduced during the reaction for a first-stage reductive leaching. The amount of sulfur dioxide added was the sum of 0.8 times the molar amount of high-valence cobalt and 1.2 times the molar amount of high-valence manganese in the battery black powder. The reaction time was 1 hour. After the reaction was completed, solid-liquid separation was performed to obtain a first-stage reductive leaching solution and acid leaching residue. The first-stage reductive leaching solution was further subjected to precision filtration to obtain a first-stage fine leaching filter. The acid leaching residue is mixed with water and slurryed at a solid-liquid ratio of 1:3.5. Sulfuric acid is added for high-acid leaching, and the pH of the slurry is adjusted to 0.5. After reacting for 1.5 hours, solid-liquid separation is performed to obtain a second-stage high-acid leaching solution and a second-stage high-acid leaching residue. The second-stage high-acid leaching solution can be returned to the first-stage leaching process to slurry with battery black powder. The second-stage high-acid leaching residue is subjected to three-stage pressure filtration and CCD washing to obtain qualified second-stage high-acid leaching residue, which is then packaged.

[0111] (3) Iron powder was added to the first-stage leaching filtrate to remove copper. The mass of the added iron powder was 1.10 times the theoretical amount. The displacement was carried out at room temperature for 40 minutes. After the reaction was completed, sponge copper and copper-removed liquid were obtained by solid-liquid separation. Hydrogen peroxide was added dropwise to the copper-removed liquid. The amount of hydrogen peroxide was 0.8 times the molar amount of divalent iron in the copper-removed liquid. After the hydrogen peroxide was added, sodium carbonate solution was added to adjust the pH value to 4.8. The reaction was maintained at this pH value for 0.8 hours. Solid-liquid separation was then carried out to obtain iron-aluminum-removed liquid and iron-aluminum slag. The iron-aluminum slag was subjected to three-stage pressure filtration and CCD washing. After washing, qualified iron-aluminum slag was obtained. The iron-aluminum slag was then packaged.

[0112] (4) After removing iron and aluminum, add sodium hydroxide solution to adjust the pH value to 8.5 and maintain this pH value for 1.2h. After the reaction is completed, perform solid-liquid separation to obtain nickel cobalt manganese hydroxide product and a first-stage nickel cobalt manganese precipitation liquid. Add sodium hydroxide solution to the first-stage nickel cobalt manganese precipitation liquid to adjust the pH value to 10.5 and maintain this pH value for 1.2h. After the reaction is completed, perform solid-liquid separation to obtain crude nickel cobalt manganese hydroxide and a second-stage nickel cobalt manganese precipitation liquid. The crude nickel cobalt manganese hydroxide can be recycled back to the first-stage reduction leaching process after being slurried with water.

[0113] (5) After the second stage of nickel, cobalt and manganese precipitation, sulfuric acid was added dropwise to adjust the pH value to 8.2. Trisodium phosphate was added to carry out the lithium precipitation reaction. The mass of trisodium phosphate added was 1.10 times the theoretical amount. After the reaction was complete, solid-liquid separation was carried out to obtain lithium phosphate intermediate and sodium sulfate solution. The lithium phosphate intermediate was mixed with water at a solid-liquid ratio of 1:3.5 and slurry was carried out. Ferric sulfate and sulfuric acid were added for leaching. The molar ratio of lithium phosphate to ferric sulfate was 2.5:1. At the same time, sulfuric acid was added to adjust the pH value of the solution to 2.5, and lithium was dissolved in the solution to obtain a high concentration of lithium sulfate solution.

[0114] (6) The lithium sulfate solution was heated to 83°C, and sodium carbonate solution was added to precipitate lithium. The amount of sodium carbonate used was 1.2 times the theoretical amount. At the same time, the pH value of the solution was maintained at 11.0. The reaction time was 4 hours. After the reaction was completed, solid-liquid separation was performed to obtain the lithium carbonate product. Specific Implementation Example 3:

[0116] A method for short-range recovery of valuable metals from spent ternary lithium batteries includes:

[0117] (1) Waste ternary lithium batteries were discharged in sodium chloride solution for 4 hours. After discharge, they were crushed, screened and roasted at 600℃ for 2 hours. The contents of each component of the battery black powder obtained after pretreatment were: 7.0% Co, 0.2% Cu, 15% Ni, 0.5% Fe, 3.0% Al, 8.0% Mn, 0.3% Ca, 0.3% Mg, 0.1% Zn, 0.002% Pb, 0.001% Cd, 0.001% Cr and 2.5% Li.

[0118] (2) Battery black powder and water were mixed and slurried at a solid-liquid ratio of 1:4. Sulfuric acid was added to adjust the pH to 2.0. At the same time, sulfur dioxide was introduced during the reaction for a first-stage reductive leaching. The amount of sulfur dioxide added was the sum of 1.0 times the molar amount of high-valence cobalt and 1.5 times the molar amount of high-valence manganese in the battery black powder. The reaction time was 1 hour. After the reaction was completed, solid-liquid separation was performed to obtain a first-stage reductive leaching solution and acid leaching residue. The first-stage reductive leaching solution was further subjected to precision filtration to obtain a first-stage fine leaching filter. The acid leaching residue is mixed with water and slurryed at a solid-liquid ratio of 1:4. Sulfuric acid is added for high-acid leaching, and the pH of the slurry is adjusted to 0.5. After reacting for 1.5 hours, solid-liquid separation is performed to obtain a second-stage high-acid leaching solution and a second-stage high-acid leaching residue. The second-stage high-acid leaching solution can be returned to the first-stage leaching process to slurry with battery black powder. The second-stage high-acid leaching residue is subjected to three-stage pressure filtration and CCD washing to obtain qualified second-stage high-acid leaching residue, which is then packaged.

[0119] (3) Add iron powder to the first-stage leaching filtrate to remove copper. The mass of iron powder added is 1.15 times the theoretical amount. Displacement is carried out at room temperature for 40 minutes. After the reaction is completed, solid-liquid separation is performed to obtain sponge copper and copper-removed liquid. Hydrogen peroxide is added dropwise to the copper-removed liquid. The amount of hydrogen peroxide is 1.0 times the content of divalent iron in the copper-removed liquid. After the hydrogen peroxide is added, sodium carbonate solution is added to adjust the pH value to 5.0. After maintaining this pH value for 1 hour, solid-liquid separation is performed to obtain iron-aluminum-removed liquid and iron-aluminum slag. The iron-aluminum slag is subjected to three-stage pressure filtration and CCD washing. After washing, qualified iron-aluminum slag is obtained. The iron-aluminum slag is then packaged.

[0120] (4) After removing iron and aluminum, add sodium hydroxide solution to adjust the pH value to 9.0 and maintain this pH value for 1.5h. After the reaction is completed, perform solid-liquid separation to obtain nickel cobalt manganese hydroxide product and a first-stage nickel cobalt manganese precipitation liquid. Add sodium hydroxide solution to the first-stage nickel cobalt manganese precipitation liquid to adjust the pH value to 11.0 and maintain this pH value for 1.5h. After the reaction is completed, perform solid-liquid separation to obtain crude nickel cobalt manganese hydroxide and a second-stage nickel cobalt manganese precipitation liquid. The crude nickel cobalt manganese hydroxide can be recycled back to the first-stage reduction leaching process after being slurried with water.

[0121] (5) After the second stage of nickel, cobalt and manganese precipitation, sulfuric acid was added dropwise to adjust the pH value to 8.5. Trisodium phosphate was added to carry out the lithium precipitation reaction. The mass of trisodium phosphate added was 1.15 times the theoretical amount. After the reaction was complete, solid-liquid separation was carried out to obtain lithium phosphate intermediate and sodium sulfate solution. The lithium phosphate intermediate was mixed with water at a solid-liquid ratio of 1:4 and slurryed. Ferric sulfate and sulfuric acid were added for leaching. The molar ratio of lithium phosphate to ferric sulfate was 2.5:1. At the same time, sulfuric acid was added to adjust the pH value of the solution to 2.5, and lithium was dissolved in the solution to obtain a high concentration of lithium sulfate solution.

[0122] (6) The lithium sulfate solution is heated to 85°C, and sodium carbonate solution is added to precipitate lithium. The amount of sodium carbonate used is 1.2 times the theoretical amount. At the same time, the pH value of the solution is maintained at 11.5. The reaction time is 5h. After the reaction is completed, solid-liquid separation is performed to obtain the lithium carbonate product.

[0123] Example 4:

[0124] A method for short-range recovery of valuable metals from waste ternary lithium batteries differs from Example 3 only in step (4): sodium hydroxide solution is added dropwise to the liquid after iron and aluminum removal to adjust the pH value to 7.5, and the reaction is maintained at this pH value for 1 hour. After the reaction is completed, solid-liquid separation is performed to obtain nickel cobalt manganese hydroxide product and a first-stage nickel cobalt manganese precipitation liquid. Sodium hydroxide solution is added to the first-stage nickel cobalt manganese precipitation liquid to adjust the pH value to 9.5, and the reaction is maintained at this pH value for 1 hour. After the reaction is completed, solid-liquid separation is performed to obtain crude nickel cobalt manganese hydroxide and a second-stage nickel cobalt manganese precipitation liquid. The crude nickel cobalt manganese hydroxide can be returned to the first-stage reduction leaching process for recycling after being slurried with water.

[0125] Example 5:

[0126] A method for short-range recovery of valuable metals from waste ternary lithium batteries differs from Example 3 only in that: sodium hydroxide is replaced with potassium hydroxide, sodium carbonate with potassium carbonate, and trisodium phosphate with tripotassium phosphate. The lithium content in the resulting lithium carbonate product is 85%. In addition, the introduction of potassium ions into the entire process requires additional wastewater treatment for potassium ions, which increases the reaction time of the entire process and also increases the wastewater treatment cost.

[0127] Comparative Example 1:

[0128] A method for short-range recovery of valuable metals from spent ternary lithium batteries includes:

[0129] (1) Reduction calcination: Take 100 parts of the disassembled and crushed ternary lithium battery cathode material, mix it evenly with 20 parts of carbon powder, place it in a reduction furnace, heat it to 600℃, and keep it warm for 1.5h.

[0130] (2) Water soaking: Pour the roasted material that has been fully roasted and reduced in step (1) into 100 parts of the reduction solution while it is still hot, and soak for 0.5 hours;

[0131] (3) Selective lithium extraction: Add 5% dilute sulfuric acid to the mixed liquid after water immersion in step (2) to adjust the solution pH to 2.0, react for 2.5 h, then adjust the pH to 8.5, react for 1 h to precipitate alkali, and filter to achieve solid-liquid separation of lithium liquid from metal slag such as nickel, cobalt, and manganese.

[0132] (4) Acid leaching: Add 300 parts of pure water to the filter cake obtained by filtration in step (3), slurry it, pump it into a stirred reactor, heat it to 60°C, add concentrated sulfuric acid, keep the pH value of the calcined mixture in the stirred reactor at 0.5, add 5g / L hydrogen peroxide, soak for 1 hour, filter and wash.

[0133] (5) Purification of nickel-cobalt-manganese solution: Adjust the pH of the mixed filtrate obtained in (4) to 2.0, filter, and analyze to obtain Fe2O3, Al2O3 products and a second filtrate; add 1.0 times the theoretical amount of fluoride salt to the second filtrate, stir at 50°C for 1 hour, filter, and obtain CaF2, MgF2, LiF filter cake and nickel-cobalt-manganese salt mixture; after the nickel-cobalt-manganese leaching solution has undergone iron, aluminum, calcium, magnesium and lithium removal processes, the purified liquid is further purified to obtain the purified liquid; then organically extract the cobalt, manganese and nickel in the purified liquid, and the extraction rates of nickel, cobalt and manganese after extraction are 8%, 24% and 60%, respectively.

[0134] Although the lithium recovery rate in the steps described in this comparative example can reach 95%, the impurity content is relatively high, with the LiF content being only 10wt%. Subsequent impurity removal and purification operations are still required. In addition, the extraction method is used for impurity removal, and the entire process takes 15 hours, while the entire process in Examples 1-4 takes between 11-12 hours. The examples save at least 3 hours compared to this comparative example. At the same time, for every ton of black powder processed, up to 40 tons of raffinate are required, which needs to be further treated to meet wastewater discharge standards. However, the treatment method in this example does not use extraction for impurity removal, and the wastewater generated in the entire process is recycled within the process, eliminating any wastewater treatment costs.

[0135] Comparative Example 2:

[0136] A method for short-range recovery of valuable metals from waste ternary lithium batteries differs from Example 3 only in that step (5) is omitted and step (6) is adjusted as follows: the liquid after the two-stage nickel-cobalt-manganese precipitation is heated to 95°C, sodium carbonate solution is added to precipitate lithium, while maintaining the pH of the solution at 11.5, the reaction time is 5h, and after the reaction is completed, solid-liquid separation is performed to obtain lithium carbonate product.

[0137] Comparative Example 3:

[0138] A method for short-range recovery of valuable metals from waste ternary lithium batteries differs from Example 3 only in that step (4) is adjusted as follows: sodium hydroxide solution is added to the liquid after iron and aluminum removal to adjust the pH value to 11.0, and this pH value is maintained for 1 hour. After the reaction is completed, solid-liquid separation is performed to obtain nickel cobalt manganese hydroxide and nickel cobalt manganese precipitated liquid.

[0139] Comparative Example 4:

[0140] A method for short-range recovery of valuable metals from waste ternary lithium batteries differs from Example 3 only in that step (4) is adjusted as follows: sodium hydroxide solution is added to the liquid after iron and aluminum removal to adjust the pH value to 9.0, and the pH value is maintained for 1 hour. After the reaction is completed, solid-liquid separation is performed to obtain nickel-cobalt-manganese hydroxide product and a first-stage nickel-cobalt-manganese precipitated liquid.

[0141] The recovery status of the main metal elements in the embodiments and comparative examples in this article is shown in the table below.

[0142]

[0143]

[0144] Industrial applicability

[0145] This method uses a two-stage chemical precipitation process to preliminarily classify the obtained nickel cobalt manganese hydroxide product. The first stage, with a pH of 8-9, precipitates a nickel cobalt manganese hydroxide product with relatively high purity. The second stage adjusts the pH to 10-11, precipitating a nickel cobalt manganese hydroxide product with relatively higher impurity content. The method is simple to operate, has low production costs, and high recovery rates. At the same time, it generates very little wastewater, reducing wastewater treatment costs and improving production efficiency.

[0146] This method first precipitates lithium using trisodium phosphate, then converts it by leaching with ferric sulfate to obtain a high-concentration lithium-containing solution. Finally, it precipitates lithium using sodium carbonate to obtain a lithium carbonate product with a high lithium content, achieving efficient lithium recovery. This provides a short and efficient wet recovery method for lithium, overcoming the problem of high impurity content in lithium carbonate in existing technologies, and obtaining higher quality lithium carbonate. Moreover, the entire process is carried out under normal pressure, which is conducive to industrial production.

[0147] Compared to traditional wet recycling technology for spent ternary lithium batteries, this solution has advantages such as a shorter process flow and lower production costs. It eliminates the complex process of using extraction + MVR evaporation crystallization to recover nickel, cobalt, and manganese metals and then using MVR concentration to recover lithium metals, which greatly reduces the energy consumption and environmental pollution of the spent ternary lithium battery recycling process.

Claims

1. A method for short-range recovery of valuable metals from spent ternary lithium batteries, characterized in that, include: The process involves sequentially performing a first-stage and a second-stage nickel-cobalt-manganese precipitation process on the iron-aluminum-removed liquid, followed by solid-liquid separation to obtain nickel-cobalt-manganese hydroxide and a post-precipitation liquid. The pH value in the first-stage nickel-cobalt-manganese precipitation step is 8-9, and the pH value in the second-stage step is 10-11. The post-precipitation liquid is obtained from battery black powder through sequential pyrolysis, a first-stage reduction leaching, copper removal, and iron-aluminum removal. Lithium precipitation with trisodium phosphate involves precipitating lithium from the solution after nickel-cobalt-manganese precipitation, followed by solid-liquid separation to obtain an intermediate lithium phosphate product and a sodium salt solution. Specifically, this includes adding a first acid solution to the solution after nickel-cobalt-manganese precipitation to adjust the pH to 8.0-8.5, and then adding trisodium phosphate to precipitate lithium. The mass of trisodium phosphate added is 1.05-1.15 times the theoretical amount. Lithium phosphate leaching: Iron salt and a first acid solution are added to the slurry of the lithium phosphate intermediate for leaching, followed by solid-liquid separation to obtain iron phosphate residue and lithium salt solution; the iron salt is iron sulfate, and the molar ratio of lithium phosphate to iron sulfate is (2.3-2.7):1; Lithium carbonate is precipitated by adding carbonate to the lithium salt solution and then separating the solid and liquid phases to obtain lithium carbonate.

2. The method for short-range recovery of valuable metals from spent ternary lithium batteries according to claim 1, characterized in that, The first acid solution is sulfuric acid or hydrochloric acid.

3. The method for short-range recovery of valuable metals from spent ternary lithium batteries according to claim 1, characterized in that, The slurry of the lithium phosphate intermediate is obtained by first pulping lithium phosphate and water at a solid-liquid mass ratio of 1: (3-4).

4. The method for short-range recovery of valuable metals from spent ternary lithium batteries according to claim 1, characterized in that, In the lithium phosphate leaching step, the first acid solution is sulfuric acid, which is used to adjust the pH of the solution to 2.5-3.

5.

5. A method for short-range recovery of valuable metals from spent ternary lithium batteries according to claim 1, characterized in that, In the lithium carbonate precipitation step, the reaction temperature is 80℃-85℃ and the reaction time is greater than 2 hours.

6. The method for short-range recovery of valuable metals from spent ternary lithium batteries according to claim 1, characterized in that, In the step of precipitating lithium carbonate, the pH of the solution is first adjusted to 10.5-11.5, and then water-soluble carbonate is added. The mass of the water-soluble carbonate added is 1.1-1.3 times the theoretical amount.

7. The method for short-range recovery of valuable metals from spent ternary lithium batteries according to claim 1, characterized in that, The battery black powder is obtained by immersing ternary lithium batteries in salt water for discharge, and then crushing and sieving the discharged ternary lithium batteries.

8. The method for short-range recovery of valuable metals from spent ternary lithium batteries according to claim 1, characterized in that, The temperature for pyrolysis of battery black powder is 400℃-600℃, and the pyrolysis time is 1 h-3 h.

9. A method for short-range recovery of valuable metals from spent ternary lithium batteries according to claim 1, characterized in that, The first stage of reduction leaching involves adding water to the pyrolyzed battery black powder for a second slurrying, then adjusting the pH value to 1-2 using a second acid solution, and introducing a first reducing agent into the slurry for reduction leaching. After leaching is completed, solid-liquid separation is performed to obtain acid leaching residue and reduction leaching solution.

10. A method for short-range recovery of valuable metals from spent ternary lithium batteries according to claim 9, characterized in that, The solid-liquid mass ratio of battery black powder and water in the slurry obtained in the second slurry step is 1:(3-4).

11. A method for short-range recovery of valuable metals from spent ternary lithium batteries according to claim 9, characterized in that, The second acid solution is sulfuric acid or hydrochloric acid.

12. A method for short-range recovery of valuable metals from spent ternary lithium batteries according to claim 9, characterized in that, The first reducing agent is sodium metabisulfite or sulfur dioxide, and the amount of the first reducing agent added is the sum of 0.5-1 times the molar amount of trivalent cobalt and 1-1.5 times the molar amount of trivalent manganese in the black powder.

13. A method for short-range recovery of valuable metals from spent ternary lithium batteries according to claim 9, characterized in that, The time for a single reductive leaching step is 1-2 hours.

14. A method for short-range recovery of valuable metals from spent ternary lithium batteries according to claim 9, characterized in that, Also includes: In the second-stage high-acid leaching, the acid leaching residue is mixed with water for a third pulping, followed by the addition of a third acid solution for high-acid leaching. After leaching, solid-liquid separation is performed to obtain the second-stage high-acid leaching residue and the second-stage high-acid leaching solution.

15. A method for short-range recovery of valuable metals from spent ternary lithium batteries according to claim 14, characterized in that, The second-stage high-acid leachate is returned to the first-stage reduction leaching step for mixing and pulping with black powder.

16. A method for short-range recovery of valuable metals from spent ternary lithium batteries according to claim 14, characterized in that, In the third pulping step, the acid leaching residue and water are pulped at a solid-liquid mass ratio of 1:(3-4).

17. A method for short-range recovery of valuable metals from spent ternary lithium batteries according to claim 14, characterized in that, The third acid solution is sulfuric acid or hydrochloric acid.

18. A method for short-range recovery of valuable metals from spent ternary lithium batteries according to claim 14, characterized in that, In the two-stage high-acid leaching step, a third acid solution is added to adjust the hydrogen ion equivalent of the slurry to 4N.

19. A method for short-range recovery of valuable metals from spent ternary lithium batteries according to claim 14, characterized in that, The high acid leaching time is 1-2 hours.

20. A method for short-range recovery of valuable metals from spent ternary lithium batteries according to claim 9, characterized in that, The copper removal step includes adding a second reducing agent to the reducing leaching solution to carry out a copper removal reaction. After the copper removal reaction is completed, solid-liquid separation is performed to obtain sponge copper and copper-removed liquid.

21. A method for short-range recovery of valuable metals from spent ternary lithium batteries according to claim 20, characterized in that, The second reducing agent is iron powder, and the mass of the iron powder added is 1.05-1.15 times the theoretical amount.

22. A method for short-range recovery of valuable metals from spent ternary lithium batteries according to claim 9, characterized in that, The reduction leaching solution is further filtered twice, and the separated liquid phase enters the copper removal step, while the solid phase is mixed with the acid leaching residue for high-acid leaching.

23. A method for short-range recovery of valuable metals from spent ternary lithium batteries according to claim 20, characterized in that, The iron and aluminum removal step includes adding an oxidant to the copper-removed liquid to carry out an iron and aluminum removal reaction. After the iron and aluminum removal reaction is completed, solid-liquid separation is performed to obtain iron and aluminum slag and iron and aluminum-removed liquid.

24. A method for short-range recovery of valuable metals from spent ternary lithium batteries according to claim 23, characterized in that, The oxidant is hydrogen peroxide, and the amount of hydrogen peroxide added is 0.5-1.0 times the molar amount of divalent iron in the solution after copper removal.

25. A method for short-range recovery of valuable metals from spent ternary lithium batteries according to claim 23, characterized in that, After the iron and aluminum removal reaction is completed, adjust the pH value to 4.5-5.0 and maintain it for 30-60 minutes before solid-liquid separation.

26. A method for short-range recovery of valuable metals from spent ternary lithium batteries according to claim 23, characterized in that, The first-stage nickel-cobalt-manganese precipitation step includes adding alkaline solution to the iron and aluminum removal liquid to adjust the pH value to 8-9 and maintaining it for 60-90 minutes, then performing solid-liquid separation to obtain refined nickel-cobalt-manganese hydroxide product and the first-stage nickel-cobalt-manganese precipitation liquid. The two-stage nickel-cobalt-manganese precipitation step includes adding alkali solution to the post-precipitation solution of the first-stage nickel-cobalt-manganese precipitation to adjust the pH value to 10-11 and maintaining it for 60-90 minutes, followed by solid-liquid separation to obtain crude nickel-cobalt-manganese hydroxide product and post-precipitation solution.

27. A method for short-range recovery of valuable metals from spent ternary lithium batteries according to claim 26, characterized in that, The alkaline solution is an aqueous solution of a strong alkali.

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