Method for short-range recovery of valuable metal from waste ternary lithium battery

Abstract

Disclosed is a method for short-range recovery of a valuable metal from a waste ternary lithium battery. By means of the steps of nickel and cobalt precipitation by a two-stage chemical precipitation method and trisodium phosphate-based lithium precipitation, the problem in the prior art of high content of impurities in lithium carbonate is solved and high-quality lithium carbonate is obtained; in addition, the whole process is carried out in a normal pressure environment. Compared with the complex process of recovering nickel, cobalt, and manganese metals by an extraction + MVR evaporative crystallization method and recovering a lithium metal after MVR concentration, the demand of a waste ternary lithium battery recovery process for energy consumption and the pollution of the waste ternary lithium battery recovery process to the environment are greatly reduced, and industrial production is facilitated.

Description

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

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

[0002] Since entering the market in 1992, lithium-ion batteries have been widely used in electronic information products such as cameras, mobile phones, and laptop computers, serving as power sources. Lithium-ion batteries are excellent secondary batteries with advantages such as high operating voltage, high specific capacity, long cycle life, and excellent safety. They are typically composed of a positive electrode, a negative electrode, a separator, an electrolyte, and a binder. During operation, lithium ions are embedded in and deintercalated between the positive and negative electrodes. During charging, lithium ions are deintercalated from the positive electrode and transferred through the electrolyte to the negative electrode. Released electrons are transferred from the outside to the negative electrode to maintain charge balance at the negative electrode. This process oxidizes cobalt ions, leaving the positive electrode lithium-deficient. During discharge, the opposite occurs: lithium ions are deintercalated and transferred to the positive electrode, while cobalt ions are reduced, leaving the negative electrode lithium-deficient. With the widespread use of lithium-ion batteries, a large number of used lithium-ion batteries have emerged. These used lithium-ion batteries contain a large amount of valuable metals and toxic chemicals. Landfilling them as municipal waste pollutes the environment and wastes resources.

[0003] Lithium-ion batteries gradually lose capacity during their charge-discharge cycles. Generally, a battery is considered ready for retirement when its capacity drops to 70-80%. Industrially, the recycling of spent lithium-ion batteries is primarily divided into two cycles: secondary use and recycling. Lithium iron phosphate batteries, due to their superior cycle performance, are primarily recycled, while ternary lithium batteries, due to their inclusion of valuable metals such as lithium, nickel, and cobalt, are primarily recycled.

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

[0005] There are a lot of studies on the recovery of valuable metals in waste ternary lithium batteries in the prior art. CN116121544A uses an extractant to recover some metals, resulting in a large amount of wastewater output and high energy consumption for wastewater treatment, which is not conducive to industrial production.

[0006] In view of this, this article is proposed.

[0007] Summary of the Invention

[0008] The purpose of this paper is to provide a method for short-range recovery of valuable metals from waste ternary lithium batteries, improve the metal recovery rate and realize the comprehensive utilization of waste batteries.

[0009] This article implements it as follows:

[0010] In a first aspect, this article provides a method for short-range recovery of valuable metals from waste ternary lithium batteries, comprising:

[0011] Nickel, cobalt and manganese precipitation, comprising sequentially subjecting the iron and aluminum removal solution to a first-stage nickel, cobalt and manganese precipitation and a second-stage nickel, cobalt and manganese precipitation, and solid-liquid separation to obtain nickel, cobalt and manganese hydroxide and a nickel, cobalt and manganese precipitation solution; wherein the pH value in the first-stage nickel, cobalt and manganese precipitation step is 8-9, and the pH value in the second-stage nickel, cobalt and manganese precipitation step is 10-11, and the iron and aluminum removal solution is obtained by sequentially subjecting battery black powder to pyrolysis, first-stage reduction leaching, copper removal, and iron and aluminum removal;

[0012] Trisodium phosphate lithium precipitation, using trisodium phosphate to precipitate lithium in the solution after nickel, cobalt and manganese precipitation, and perform solid-liquid separation to obtain lithium phosphate intermediate and sodium salt solution.

[0013] Lithium phosphate leaching, adding iron salt and a first acid solution to the lithium phosphate intermediate slurry for leaching, and then performing solid-liquid separation to obtain iron phosphate slag and a lithium salt solution;

[0014] Lithium carbonate is precipitated, and carbonate is added to the lithium salt solution to obtain lithium carbonate after solid-liquid separation.

[0015] In some embodiments, a first acid solution is added to the solution after nickel, cobalt and manganese precipitation to adjust the pH value to 8.0-8.5, and then trisodium phosphate is added to precipitate lithium, and the mass of the trisodium phosphate added is 1.05-1.15 times the theoretical amount.

[0016] In some embodiments, the first acid solution is sulfuric acid or hydrochloric acid.

[0017] In some embodiments, the slurry of the lithium phosphate intermediate is obtained by first slurrying lithium phosphate and water at a solid-liquid ratio of 1:(3-4).

[0018] In some embodiments, in the lithium phosphate leaching step, the iron salt is ferric sulfate, and the molar ratio of the lithium phosphate to ferric sulfate is (2.3-2.7):1.

[0019] In some embodiments, in the lithium phosphate leaching step, the first acid solution is sulfuric acid, and the pH value of the solution is adjusted to 2.5-3.5 using the first acid solution. In some embodiments, in the lithium carbonate precipitation step, the reaction temperature is 80°C-85°C, and the reaction time is greater than 2 hours.

[0020] In some embodiments, in the lithium carbonate precipitation step, the pH value of the solution is first adjusted to 10.5-11.5 and then a water-soluble carbonate is added, wherein the mass of the water-soluble carbonate added is 1.1-1.3 times the theoretical amount.

[0021] In some embodiments, the battery black powder is obtained by immersing a ternary lithium battery in salt water for discharge, and then crushing and screening the discharged ternary lithium battery.

[0022] In some embodiments, the temperature for pyrolyzing the battery black powder is 400° C.-600° C., and the pyrolysis time is 1 hour-3 hours.

[0023] In some embodiments, the first stage reduction leaching is to add water to the battery black powder after pyrolysis for a second slurry, then use a second acid solution to adjust the pH value to 1-2, and introduce a first reducing agent into the slurry for reduction leaching. After the leaching is completed, solid-liquid separation is performed to obtain acid leaching residue and reduction leaching liquid.

[0024] In some embodiments, the solid-to-liquid ratio of battery black powder to water in the slurry obtained in the second slurrying step is 1:(3-4).

[0025] In some embodiments, the second acid solution is sulfuric acid or hydrochloric acid.

[0026] 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.

[0027] In some embodiments, the duration of one reduction leaching step is 1 hour to 2 hours.

[0028] In some embodiments, further comprising:

[0029] Second stage high acid leaching, mixing the acid leaching residue with water for a third slurrying, then adding a third acid solution for high acid leaching, and performing solid-liquid separation after the leaching is completed to obtain second stage high acid leaching residue and second stage high acid leaching solution;

[0030] The high-acid leaching residue is washed, and the second-stage high-acid leaching residue is washed and filtered to obtain high-acid leaching residue containing carbon powder.

[0031] In some embodiments, the second-stage high-acid leaching solution is returned to the first-stage reduction leaching step for mixing with black powder into slurry.

[0032] In some embodiments, in the third slurrying step, the acid leaching residue and water are slurried at a solid-to-liquid ratio of 1:(3-4).

[0033] In some embodiments, the third acid solution is sulfuric acid or hydrochloric acid.

[0034] In some embodiments, in the second-stage high-acid leaching step, a third acid solution is added to adjust the slurry hydrogen ion equivalent to 4N.

[0035] In some embodiments, the high acid leaching time is 1 hour to 2 hours.

[0036] In some embodiments, the copper removal step includes adding a second reducing agent to the reduced 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 a copper-removed liquid.

[0037] In some embodiments, the second reducing agent is iron powder, and the added mass of the iron powder is 1.05-1.15 times the theoretical amount.

[0038] In some embodiments, the reduction leaching solution is further filtered twice, the separated liquid phase enters the copper removal step, and the solid phase is mixed with the acid leaching residue to perform high acid leaching.

[0039] In some embodiments, the iron-aluminum removal step includes adding an oxidant to the copper-removed liquid to carry out an iron-aluminum removal reaction, and after the iron-aluminum removal reaction is completed, solid-liquid separation is performed to obtain iron-aluminum slag and iron-aluminum-removed liquid.

[0040] 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 solution after copper removal.

[0041] 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 minutes to 60 minutes before solid-liquid separation.

[0042] In some embodiments,

[0043] The one-stage nickel, cobalt and manganese precipitation step comprises adding alkali solution to the iron and aluminum removal solution to adjust the pH value to 8-9 and maintain it for 60-90 minutes, and then performing solid-liquid separation to obtain a refined nickel, cobalt and manganese hydroxide product and a one-stage nickel, cobalt and manganese precipitation solution;

[0044] The second stage nickel-cobalt-manganese precipitation step includes continuously adding alkali solution to the first stage nickel-cobalt-manganese precipitation solution to adjust the pH value to 10-11 and maintain it for 60-90 minutes, and then performing solid-liquid separation to obtain a crude nickel-cobalt-manganese hydroxide product and a nickel-cobalt-manganese precipitation solution.

[0045] In some embodiments, the alkali solution is an aqueous solution of a strong base.

[0046] This article has the following beneficial effects:

[0047] This scheme can preliminarily classify the obtained nickel cobalt manganese hydroxide products through a two-stage chemical precipitation method. The pH value of the first stage is 8-9, which can precipitate nickel cobalt manganese hydroxide products with relatively high purity. The pH value of the second stage is adjusted to 10-11, and nickel cobalt manganese hydroxide products with relatively high impurity content are precipitated. The scheme is simple to operate, has low production costs and high recovery rates. At the same time, the amount of wastewater generated is extremely small, which reduces wastewater treatment costs and improves production efficiency.

[0048] This solution first precipitates lithium through trisodium phosphate, then leaches and converts it through iron salt and the first acid solution to obtain a high-concentration lithium-containing solution, and then precipitates lithium with sodium carbonate to obtain a lithium carbonate product with a high main content, achieving efficient lithium recovery and providing a wet recovery method with a short process and high efficiency for lithium recovery. It also overcomes the problem of high impurity content of lithium carbonate in the existing technology and obtains higher-quality lithium carbonate. Moreover, the entire process is carried out under normal pressure, which is conducive to industrial production.

[0049] Compared with the traditional wet recycling technology of waste ternary lithium batteries, this solution has the advantages of short process flow and low production cost. It eliminates the complex process of using extraction + MVR evaporation crystallization to recover nickel, cobalt and manganese metals and recovering lithium metal after MVR concentration in the traditional process, greatly reducing the energy consumption demand and environmental pollution in the recycling process of waste ternary lithium batteries. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the technical solutions of the embodiments of this invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of this invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0051] Figure 1 is the flow chart of this article;

[0052] FIG2 is a flow chart of an embodiment of the present invention. DETAILED DESCRIPTION

[0053] To make the purpose, technical solutions and advantages of the embodiments herein clearer, the technical solutions in the embodiments herein are described clearly and completely below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer were followed. Where the manufacturer of the reagents or instruments used is not specified, all are commercially available conventional products.

[0054] This embodiment provides a method for recovering valuable metals from waste ternary lithium batteries in a short-range manner, as shown in FIG1 , comprising:

[0055] Nickel, cobalt and manganese precipitation, comprising sequentially subjecting the iron and aluminum removal solution to a first-stage nickel, cobalt and manganese precipitation and a second-stage nickel, cobalt and manganese precipitation, and solid-liquid separation to obtain nickel, cobalt and manganese hydroxide and a nickel, cobalt and manganese precipitation solution; wherein the pH value in the first-stage nickel, cobalt and manganese precipitation step is 8-9, and the pH value in the second-stage nickel, cobalt and manganese precipitation step is 10-11, and the iron and aluminum removal solution is obtained by sequentially subjecting battery black powder to pyrolysis, first-stage reduction leaching, copper removal, and iron and aluminum removal;

[0056] Trisodium phosphate lithium precipitation, using trisodium phosphate to precipitate lithium in the solution after nickel, cobalt and manganese precipitation, and perform solid-liquid separation to obtain lithium phosphate intermediate and sodium salt solution.

[0057] Lithium phosphate leaching, adding iron salt and a first acid solution to the lithium phosphate intermediate slurry for leaching, and then performing solid-liquid separation to obtain iron phosphate slag and a lithium salt solution;

[0058] Lithium carbonate is precipitated, carbonate is added to the lithium salt solution, and lithium carbonate is obtained after solid-liquid separation.

[0059] This solution uses a two-stage chemical precipitation method to perform preliminary classification of the obtained nickel, cobalt, and manganese hydroxide products. The pH value of the first stage is 8-9, which can precipitate a relatively high-purity nickel, cobalt, and manganese hydroxide product. The pH value of the second stage is adjusted to 10-11, precipitating a nickel, cobalt, and manganese hydroxide product with a relatively high impurity content. The method is simple to operate, has low production costs, and a high recovery rate. It also generates minimal wastewater, reducing wastewater treatment costs and improving production efficiency. Compared to the one-step precipitation method, the two-stage chemical precipitation method has certain advantages in terms of the overall recovery rate and quality of the nickel, cobalt, and manganese hydroxide products obtained, and is also conducive to improving the subsequent recovery rate of lithium metal and the quality of lithium carbonate products.

[0060] This solution first uses trisodium phosphate to precipitate lithium, then uses iron salts and a first acid solution for leaching and conversion to obtain a high-concentration lithium-containing solution, and then uses sodium carbonate to precipitate lithium to obtain a lithium carbonate product with a high main content, achieving efficient lithium recovery. It provides a wet recovery method for lithium with a short process and high efficiency, and overcomes the problem of high impurity content of lithium carbonate in the existing technology, obtaining high-quality lithium carbonate. Moreover, the entire process is carried out under normal pressure, which is conducive to industrial production. Using trisodium phosphate to precipitate lithium, due to the introduction of sodium salt, the sodium ion concentration of the solution is increased. When the sodium ion content reaches a certain concentration, it is conducive to the precipitation of lithium, thereby improving the recovery rate and quality of lithium carbonate.

[0061] In this scheme, in order to provide a high-sodium environment for the precipitation of lithium carbonate, when recovering other metals, sodium ions can be selected as cations as much as possible under the conditions that meet the needs. At the same time, in order to make the treatment of discharged wastewater more difficult and facilitate recovery or treatment, sulfate ions can be selected as anions as much as possible to facilitate the generation of sodium sulfate solution for reuse, which has relatively little impact on the environment.

[0062] Compared with the traditional wet recycling technology of waste ternary lithium batteries, this solution has the advantages of short process flow and low production cost. It eliminates the complex process of using extraction + MVR evaporation crystallization to recover nickel, cobalt and manganese metals and recovering lithium metal after MVR concentration in the traditional process, greatly reducing the energy consumption demand and environmental pollution in the recycling process of waste ternary lithium batteries.

[0063] In some embodiments, a first acid solution is added to the solution after nickel, cobalt and manganese precipitation to adjust the pH value to 8.0-8.5, and then trisodium phosphate is added to precipitate lithium, and the mass of the trisodium phosphate added is 1.05-1.15 times the theoretical amount.

[0064] A slight excess of trisodium phosphate is added to facilitate more complete precipitation of lithium ions. Specifically, in this solution, the pH value can be adjusted to 8.0, 8.1, 8.2, 8.3, 8.4, 8.5, or any value between 8.0 and 8.5. The added mass of trisodium phosphate can be 1.05 times, 1.1 times, 1.15 times, or any value between 1.05 and 1.15 times the theoretical amount.

[0065] In some embodiments, the first acid solution is sulfuric acid or hydrochloric acid, and sulfuric acid is beneficial to the recovery and utilization of subsequent products.

[0066] In some embodiments, the slurry of the lithium phosphate intermediate is obtained by first slurrying lithium phosphate and water at a solid-to-liquid ratio (mass ratio, all subsequent solid-to-liquid ratios are solid-to-liquid mass ratios) of 1:(3-4).

[0067] In some embodiments, in the lithium phosphate leaching step, the iron salt is ferric sulfate, and the molar ratio of the lithium phosphate to ferric sulfate is (2.3-2.7):1.

[0068] In some embodiments, during the lithium phosphate leaching step, the first acid solution is sulfuric acid, and the pH of the solution is adjusted to 2.5-3.5 using the first acid solution. In some embodiments, during the lithium carbonate precipitation step, the reaction temperature is 80°C-85°C, specifically 80°C, 81°C, 82°C, 83°C, 84°C, 85°C, or any value between 80°C and 85°C; the reaction time is greater than 3 hours. Generally, the reaction is stopped when no precipitate is formed or the formation rate falls below a preset standard.

[0069] In some embodiments, in the step of precipitating lithium carbonate, the pH value of the solution is first adjusted to 10.5-11.5 and then a water-soluble carbonate is added. Specifically, the pH value of the solution can be adjusted to 10.5, 10.7, 10.9, 11.1, 11.3, 11.5 or any value between 10.5 and 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 1.1 times, 1.15 times, 1.2 times, 1.25 times, 1.3 times or any value between 1.1 and 1.3 times.

[0070] In some embodiments, the battery black powder is obtained by immersing a ternary lithium battery in salt water for discharge, and then crushing and screening the discharged ternary lithium battery.

[0071] In this embodiment, the composition of the battery black powder varies with different ternary lithium batteries, but is applicable to this embodiment.

[0072] When discharging, the used ternary lithium battery can be discharged with sodium carbonate or sodium chloride brine, and the discharge time is generally greater than 2 hours.

[0073] In some embodiments, the temperature for pyrolysis of battery black powder is 400°C-600°C, specifically 400°C, 450°C, 500°C, 550°C, 600°C or any value between 400°C-600°C; the pyrolysis time is 1h-3h, specifically 1h, 1.5h, 2h, 2.5h, 3h or any value between 1h-3h. Pyrolysis can remove substances such as electrolyte and diaphragm in battery black powder.

[0074] In some embodiments, the first stage reduction leaching is to add water to the battery black powder after pyrolysis for a second slurry, then use a second acid solution to adjust the pH value to 1-2, and introduce a first reducing agent into the slurry for reduction leaching. After the leaching is completed, solid-liquid separation is performed to obtain acid leaching residue and reduction leaching liquid, and the metal elements to be recovered are dissolved in the reduction leaching liquid for the next step of utilization.

[0075] In some embodiments, the solid-liquid ratio of battery black powder and water in the slurry obtained in the second slurrying step is 1: (3-4), specifically 1: 3.2, 1: 3.4, 1: 3.6, 1: 3.8, 1: 4.0 or any value between 1: (3-4), to extract undissolved metal elements, wherein the solid-liquid ratio of battery black powder and water is too low, which will reduce the metal dissolution rate. If the solid-liquid ratio is too high, the target ion content in the system is low, and the recovery rate will be reduced due to part of the solution in the solution during the later precipitation process, and the amount of wastewater generated will increase, thereby increasing the impact on the environment.

[0076] In some embodiments, the second acid solution is sulfuric acid or hydrochloric acid, preferably sulfuric acid.

[0077] 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 1 hour, 1.5 hours, 2 hours, or any value between 1 hour and 2 hours.

[0078] In some embodiments, further comprising:

[0079] Second stage high acid leaching, mixing the acid leaching residue with water for a third slurrying, then adding a third acid solution for high acid leaching, and performing solid-liquid separation after the leaching is completed to obtain second stage high acid leaching residue and second stage high acid leaching solution;

[0080] The high-acid leaching residue is washed, and the second-stage high-acid leaching residue is washed and filtered to obtain high-acid leaching residue containing carbon powder.

[0081] This embodiment adopts high acid leaching, and washes the high acid leaching residue as needed to further improve the leaching rate of the target element and increase the content of carbon powder in the acid leaching residue.

[0082] In some embodiments, the second-stage high-acid leaching solution is returned to the first reduction leaching step for mixing with black powder for slurrying, and the washing solution obtained by washing the high-acid leaching residue can also be returned to the first reduction leaching step for mixing with black powder for slurrying to reduce the loss of target elements.

[0083] In some embodiments, in the third slurrying step, the acid leaching residue is slurried with water at a solid-liquid ratio of 1:(3-4). In some embodiments, the third acid solution is sulfuric acid or hydrochloric acid, and sulfuric acid is more conducive to subsequent wastewater treatment.

[0084] In some embodiments, in the second-stage high-acid leaching step, a third acid solution is added to adjust the slurry hydrogen ion equivalent to 4N.

[0085] In some embodiments, the high acid leaching time is 1 h-2 h, specifically 1 h, 1.5 h, 2 h or any value between 1 h and 2 h.

[0086] In some embodiments, the copper removal step includes adding a second reducing agent to the reduced leaching solution to carry out a copper removal reaction, and after the copper removal reaction is completed, solid-liquid separation is performed to obtain sponge copper and a copper-removed liquid.

[0087] In some embodiments, the second reducing agent is iron powder, and the amount of iron powder added is 1.05-1.15 times the theoretical amount, specifically 1.05 times, 1.1 times, 1.15 times, or any value between 1.05-1.15 times. Using iron powder as a reducing agent does not introduce elements not already present in the system, facilitating their removal in the subsequent iron and aluminum removal step.

[0088] In some embodiments, the reduction leaching liquid is further filtered twice, the separated liquid phase enters the copper removal step, the solid phase is mixed with the acid leaching residue for high acid leaching, and the secondary filtration further separates the copper slag with smaller particle size in the liquid phase, thereby improving the recovery rate of the copper element.

[0089] In some embodiments, the iron-aluminum removal step includes adding an oxidant to the copper-removed liquid to carry out an iron-aluminum removal reaction, and after the iron-aluminum removal reaction is completed, solid-liquid separation is performed to obtain iron-aluminum slag and iron-aluminum-removed liquid.

[0090] 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 ferrous iron in the solution after copper removal. The hydrogen peroxide is reduced to water and no new impurities are introduced.

[0091] 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 minutes to 60 minutes before solid-liquid separation.

[0092] Specifically, in this embodiment, the pH value can be adjusted to 4.5, 4.6, 4.7, 4.8, 4.9, 5.0, or any value between 4.5 and 5.0; the holding time can be adjusted to 30 minutes, 40 minutes, 50 minutes, 60 minutes, or any value between 30 minutes and 60 minutes. After adjusting the pH value, the solution is maintained for a period of time to allow the iron and aluminum to fully precipitate before solid-liquid separation. Rapid stirring is avoided as much as possible during pH maintenance.

[0093] In some embodiments,

[0094] The one-stage nickel, cobalt and manganese precipitation step includes adding alkali solution to the iron and aluminum removal liquid to adjust the pH value to 8-9 and maintaining it for 60 minutes to 90 minutes, and then performing solid-liquid separation to obtain a refined nickel, cobalt and manganese hydroxide product and a one-stage nickel, cobalt and manganese precipitation liquid; specifically, the pH value can be adjusted to 8.0, 8.2, 8.4, 8.6, 8.8, 9.0 or any value between 8 and 9; the maintenance time can be adjusted to 60 minutes, 70 minutes, 80 minutes, 90 minutes or any value between 60 minutes and 90 minutes.

[0095] The second-stage nickel, cobalt and manganese precipitation step includes continuously adding alkali solution to the first-stage nickel, cobalt and manganese precipitation liquid to adjust the pH value to 10-11 and maintain it for 60 minutes to 90 minutes, and then performing solid-liquid separation to obtain a crude nickel, cobalt and manganese hydroxide product and the nickel, cobalt and manganese precipitation liquid; specifically, the pH value can be adjusted to 10.0, 10.2, 10.4, 10.6, 10.8, 11.0 or any value between 8 and 9; the maintenance time can be adjusted to 60 minutes, 70 minutes, 80 minutes, 90 minutes or any value between 60 minutes and 90 minutes.

[0096] In some embodiments, the alkali solution is an aqueous solution of a strong base. In this embodiment, sodium hydroxide can be selected to facilitate wastewater treatment and precipitation of lithium carbonate in the subsequent step.

[0097] It should be noted that the main purpose of the acid and base in this article is to adjust the pH value, so the concentration has little effect on the system. A higher concentration solution or a lower concentration solution 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.

[0098] In this article, each solid-liquid separation step can adopt a conventional solid-liquid separation method, such as filter press; the solid phase residue obtained in each solid-liquid separation step can also be washed before entering the next process, and the washing liquid can be returned to the previous step for reuse. Specifically, the solid phase residue can be washed by pulping and then filter press, or by CCD countercurrent washing and then filter press.

[0099] The features and performance of this invention are further described in detail below in conjunction with the embodiments.

[0100] Example 1

[0101] A method for short-range recovery of valuable metals from waste ternary lithium batteries, the specific process of which is shown in Figure 2, includes:

[0102] (1) The waste ternary lithium battery was immersed in a sodium chloride solution for discharge treatment. The discharge time was 2 hours. After the discharge was completed, it was crushed, screened and roasted. The roasting temperature was 400℃ and the roasting time was 1 hour. The mass fractions of the components 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.

[0103] (2) Battery black powder and water are mixed into a slurry at a solid-liquid ratio of 1:3, sulfuric acid is added to adjust the pH value to 1.0, and sulfur dioxide is introduced during the reaction process to perform a reduction leaching. The amount of sulfur dioxide used is 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 is 1 hour. After the reaction is completed, solid-liquid separation is performed to obtain a reduction leaching solution and acid leaching residue. The reduction leaching solution is further subjected to precise filtration to obtain a leaching filtrate. The acid leaching residue is further subjected to precise filtration to obtain a leaching filtrate. The leaching residue is mixed with water to form a slurry, and the acid leaching residue is mixed with water at a solid-liquid ratio of 1:3. Sulfuric acid is added for high-acid leaching, and the pH value 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 liquid and a second-stage high-acid leaching residue. The second-stage high-acid leaching liquid is returned to the first-stage leaching process to be slurried with battery black powder; the second-stage high-acid leaching residue is washed to obtain qualified second-stage high-acid leaching residue after washing, and the high-acid leaching residue is then packaged for treatment. The main component of the high-acid leaching residue is carbon powder.

[0104] (3) Iron powder is added to the first-stage leaching filtrate to remove copper. The mass of the added iron powder is 1.05 times the theoretical amount (theoretical amount of reduced copper). The replacement is carried out at room temperature for 40 minutes. After the reaction is completed, sponge copper and copper-removed liquid are obtained by solid-liquid separation. 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 addition of hydrogen peroxide is completed, sodium carbonate solution is continued to be added to adjust the pH value to 4.5. The pH value is maintained at 4.5, and the reaction is carried out for 0.5 hours. After solid-liquid separation, the iron-aluminum-removed liquid and iron-aluminum slag are obtained. The iron-aluminum slag is subjected to three-stage filter pressing CCD washing to obtain qualified iron-aluminum slag after washing, and the iron-aluminum slag is then packaged for processing.

[0105] (4) adding sodium hydroxide solution to the liquid after iron and aluminum removal to adjust the pH value to 8.0, and maintaining the pH value for 1 hour; after the reaction is completed, performing solid-liquid separation to obtain nickel-cobalt-manganese hydroxide product and a first-stage nickel-cobalt-manganese precipitation liquid; continuing to add sodium hydroxide solution to the first-stage nickel-cobalt-manganese precipitation liquid to adjust the pH value to 10.0, and maintaining the pH value for 1 hour; after the reaction is completed, performing 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 slurried with water and returned to the first-stage reduction leaching process for recycling.

[0106] (5) sulfuric acid is added dropwise to the solution after the second stage nickel, cobalt and manganese precipitation to adjust the pH value to 8.0, trisodium phosphate is added to carry out lithium precipitation reaction, and the mass of trisodium phosphate added is 1.05 times the theoretical amount (theoretical amount of lithium precipitation). After the reaction is complete, solid-liquid separation is carried out to obtain a lithium phosphate intermediate and a sodium sulfate solution; the lithium phosphate intermediate is slurried with water at a solid-liquid ratio of 1:3, and ferric sulfate and sulfuric acid are added for leaching, with the molar ratio of lithium phosphate to ferric sulfate being 2.5:1. At the same time, sulfuric acid is added to adjust the pH value of the solution to 2.5, and lithium is dissolved in the solution to obtain a high-concentration lithium sulfate solution.

[0107] (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. The pH value of the solution is maintained at 10.5. The reaction time is 3 h. After the reaction is completed, solid-liquid separation is performed to obtain a lithium carbonate product.

[0108] Example 2:

[0109] A method for short-range recovery of valuable metals from waste ternary lithium batteries, comprising:

[0110] (1) The waste ternary lithium battery was placed in a sodium chloride solution for discharge treatment. The discharge time was 3 hours. After the discharge was completed, it was crushed, screened and roasted. The roasting temperature was 500°C and the roasting time was 1.5 hours. The contents of the components 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.

[0111] (2) Battery black powder and water are mixed into a slurry at a solid-liquid ratio of 1:3.5, sulfuric acid is added to adjust the pH value to 2.0, and sulfur dioxide is introduced during the reaction process to perform a reduction leaching. The amount of sulfur dioxide added is 0.8 times the molar amount of high-valent cobalt and 1.2 times the molar amount of high-valent manganese in the battery black powder. The reaction time is 1 hour. After the reaction is completed, solid-liquid separation is performed to obtain a reduction leaching solution and acid leaching residue. The reduction leaching solution is further subjected to fine filtration to obtain a leaching fine filter. liquid; the acid leaching residue is mixed with water to form a slurry, the acid leaching residue and water are mixed at a solid-liquid ratio of 1:3.5, sulfuric acid is added for high-acid leaching, the pH value of the slurry is adjusted to 0.5, and after reacting for 1.5 hours, solid-liquid separation is performed to obtain a second-stage high-acid leaching liquid and a second-stage high-acid leaching residue. The second-stage high-acid leaching liquid can be returned to the first-stage leaching process for slurrying with battery black powder; the second-stage high-acid leaching residue is subjected to a three-stage filter press CCD washing to obtain qualified second-stage high-acid leaching residue after washing, and the high-acid leaching residue is then packaged for treatment.

[0112] (3) Iron powder is added to the first-stage leaching filtrate to remove copper. The mass of the added iron powder is 1.10 times the theoretical amount. The replacement is carried out at room temperature for 40 minutes. After the reaction is completed, sponge copper and copper-removed liquid are obtained by solid-liquid separation. Hydrogen peroxide is added dropwise to the copper-removed liquid. The amount of hydrogen peroxide is 0.8 times the molar amount of divalent iron in the copper-removed liquid. After the addition of hydrogen peroxide is completed, sodium carbonate solution is added to adjust the pH value to 4.8. The pH value is maintained at 4.8, and the reaction is carried out for 0.8 hours. After solid-liquid separation, the iron-aluminum-removed liquid and iron-aluminum slag are obtained. The iron-aluminum slag is subjected to three-stage filter pressing CCD washing to obtain qualified iron-aluminum slag, which is then packaged for processing.

[0113] (4) adding sodium hydroxide solution to the liquid after iron and aluminum removal to adjust the pH value to 8.5, and maintaining the pH value for 1.2 hours; after the reaction is completed, performing solid-liquid separation to obtain nickel-cobalt-manganese hydroxide product and a first-stage nickel-cobalt-manganese precipitation liquid; continuing to add sodium hydroxide solution to the first-stage nickel-cobalt-manganese precipitation liquid to adjust the pH value to 10.5, and maintaining the pH value for 1.2 hours; after the reaction is completed, performing 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 slurried with water and returned to the first-stage reduction leaching process for recycling.

[0114] (5) Sulfuric acid is added dropwise to the solution after the second stage precipitation of nickel, cobalt and manganese to adjust the pH value to 8.2, trisodium phosphate is added to carry out lithium precipitation reaction, and the mass of trisodium phosphate added is 1.10 times the theoretical amount. After the reaction is complete, solid-liquid separation is carried out to obtain a lithium phosphate intermediate and a sodium sulfate solution; the lithium phosphate intermediate is slurried with water at a solid-liquid ratio of 1:3.5, and ferric sulfate and sulfuric acid are added for leaching, and the molar ratio of lithium phosphate to ferric sulfate is 2.5:1. At the same time, sulfuric acid is added to adjust the pH value of the solution to 2.5, and lithium is dissolved in the solution to obtain a high-concentration lithium sulfate solution.

[0115] (6) The lithium sulfate solution is heated to 83° C., and sodium carbonate solution is added to precipitate lithium. The amount of sodium carbonate used is 1.2 times the theoretical amount. The pH value of the solution is maintained at 11.0. The reaction time is 4 h. After the reaction is completed, solid-liquid separation is performed to obtain a lithium carbonate product.

[0116] Specific embodiment 3:

[0117] A method for short-range recovery of valuable metals from waste ternary lithium batteries, comprising:

[0118] (1) The waste ternary lithium battery is placed in a sodium chloride solution for discharge treatment. The discharge time is 4 hours. After the discharge is completed, it is crushed, screened and roasted. The roasting temperature is 600℃ and the roasting time is 2 hours. The contents of the components of the battery black powder obtained after pretreatment are: 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.

[0119] (2) Battery black powder and water are mixed into a slurry at a solid-liquid ratio of 1:4, sulfuric acid is added to adjust the pH value to 2.0, and sulfur dioxide is introduced during the reaction process to perform a reduction leaching. The amount of sulfur dioxide added is 1.0 times the molar amount of high-valent cobalt and 1.5 times the molar amount of high-valent manganese in the battery black powder. The reaction time is 1 hour. After the reaction is completed, solid-liquid separation is performed to obtain a reduction leaching solution and acid leaching residue. The reduction leaching solution is further subjected to fine filtration to obtain a leaching fine filter. liquid; the acid leaching residue is mixed with water to form a slurry, the acid leaching residue and water are mixed at a solid-liquid ratio of 1:4, sulfuric acid is added for high-acid leaching, the pH value of the slurry is adjusted to 0.5, and after reacting for 1.5 hours, solid-liquid separation is performed to obtain a second-stage high-acid leaching liquid and a second-stage high-acid leaching residue. The second-stage high-acid leaching liquid can be returned to the first-stage leaching process for slurrying with battery black powder; the second-stage high-acid leaching residue is subjected to a three-stage filter press CCD washing to obtain qualified second-stage high-acid leaching residue after washing, and the high-acid leaching residue is then packaged for treatment.

[0120] (3) Iron powder is added to the first-stage leaching filtrate to remove copper. The mass of the added iron powder is 1.15 times the theoretical amount. The replacement is carried out at room temperature for 40 minutes. After the reaction is completed, sponge copper and copper-removed liquid are obtained by solid-liquid separation. Hydrogen peroxide is added dropwise to the copper-removed liquid. The amount of hydrogen peroxide is 1.0 times the divalent iron content in the copper-removed liquid. After the addition of hydrogen peroxide is completed, sodium carbonate solution is added to adjust the pH value to 5.0. The pH value is maintained at this reaction value for 1 hour, and then solid-liquid separation is carried out to obtain iron-aluminum-removed liquid and iron-aluminum slag. The iron-aluminum slag is subjected to three-stage filter pressing CCD washing to obtain qualified iron-aluminum slag after washing, and the iron-aluminum slag is then packaged for processing.

[0121] (4) adding sodium hydroxide solution to the liquid after iron and aluminum removal to adjust the pH value to 9.0, and maintaining the pH value for 1.5 hours; after the reaction is completed, performing solid-liquid separation to obtain nickel-cobalt-manganese hydroxide product and a first-stage nickel-cobalt-manganese precipitation liquid; continuing to add sodium hydroxide solution to the first-stage nickel-cobalt-manganese precipitation liquid to adjust the pH value to 11.0, and maintaining the pH value for 1.5 hours; after the reaction is completed, performing 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 slurried with water and returned to the first-stage reduction leaching process for recycling.

[0122] (5) sulfuric acid is added dropwise to the solution after the second stage precipitation of nickel, cobalt and manganese to adjust the pH value to 8.5, trisodium phosphate is added to carry out lithium precipitation reaction, and the mass of trisodium phosphate added is 1.15 times the theoretical amount. After the reaction is complete, solid-liquid separation is carried out to obtain a lithium phosphate intermediate and a sodium sulfate solution; the lithium phosphate intermediate is slurried with water at a solid-liquid ratio of 1:4, and ferric sulfate and sulfuric acid are added for leaching, and the molar ratio of lithium phosphate to ferric sulfate is 2.5:1. At the same time, sulfuric acid is added to adjust the pH value of the solution to 2.5, and lithium is dissolved in the solution to obtain a high-concentration lithium sulfate solution.

[0123] (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. The pH value of the solution is maintained at 11.5. The reaction time is 5 h. After the reaction is completed, solid-liquid separation is performed to obtain a lithium carbonate product.

[0124] Example 4:

[0125] A method for short-range recovery of valuable metals from waste ternary lithium batteries, which differs from Example 3 only in that step (4) is adjusted as follows: sodium hydroxide solution is added dropwise to the liquid after iron and aluminum removal to adjust the pH value to 7.5, and the pH value is maintained for reaction for 1 hour. After the reaction is completed, solid-liquid separation is performed to obtain a nickel, cobalt and manganese hydroxide product and a first-stage nickel, cobalt and manganese precipitation liquid; sodium hydroxide solution is continued to be added to the first-stage nickel, cobalt and manganese precipitation liquid to adjust the pH value to 9.5, and the pH value is maintained for reaction for 1 hour. After the reaction is completed, solid-liquid separation is performed to obtain crude nickel, cobalt and manganese hydroxide and a second-stage nickel, cobalt and manganese precipitation liquid. The crude nickel, cobalt and manganese hydroxide can be slurried with water and returned to the first-stage reduction leaching process for recycling.

[0126] Example 5:

[0127] A method for short-range recovery of valuable metals from waste ternary lithium batteries, which differs from Example 3 only in that the sodium hydroxide used therein is replaced by potassium hydroxide, the sodium carbonate is replaced by potassium carbonate, and the trisodium phosphate is replaced by tripotassium phosphate. The lithium content of the subsequently obtained lithium carbonate product is 85%. In addition, the introduction of potassium ions in the entire process requires additional wastewater treatment for the potassium ions, which increases the reaction time of the entire process and increases a certain amount of wastewater treatment cost.

[0128] Comparative Example 1:

[0129] A method for short-range recovery of valuable metals from waste ternary lithium batteries, comprising:

[0130] (1) Reduction roasting: Take 100 parts of disassembled and crushed ternary lithium battery positive electrode materials, mix them evenly with 20 parts of carbon powder, place them in a reduction furnace, heat to 600°C, and keep warm for 1.5 hours;

[0131] (2) Water immersion: Pour the calcined material after being fully calcined and reduced in step (1) into 100 parts of the reducing solution while it is still hot and soak for 0.5 hours;

[0132] (3) Selective lithium extraction: 5% dilute sulfuric acid was added dropwise to the mixed liquid after water immersion in step (2) to adjust the pH value to 2.0, and the mixture was reacted for 2.5 hours, and then the pH value was adjusted to 8.5. The mixture was reacted for 1 hour to perform alkali precipitation, and the solid-liquid separation of the lithium solution and the metal slags such as nickel, cobalt, and manganese was achieved after filtration;

[0133] (4) Acid leaching: Add 300 parts of pure water to the filter cake obtained by filtration in step (3), slurry it, and then pump it into a stirred reactor. Heat it to 60°C, add concentrated sulfuric acid dropwise, and keep the pH value of the roasting material mixture in the stirred reactor at 0.5. At the same time, add 5g / L hydrogen peroxide dropwise. After soaking for 1 hour, filter and wash it.

[0134] (5) Purification of nickel-cobalt-manganese solution: adjusting the pH of the mixed filtrate obtained in (4) to 2.0, filtering, and analyzing to obtain Fe2O3, Al2O3 products and a second filtrate; adding 1.0 times the theoretical amount of fluoride salt to the second filtrate, stirring at a temperature of 50°C for 1 hour, filtering, and obtaining CaF2, MgF2, LiF filter cakes and a nickel-cobalt-manganese salt mixed solution; extracting the impurity-removed liquid obtained after the nickel-cobalt-manganese leachate is subjected to the steps of removing iron, aluminum, calcium, magnesium, and lithium to obtain an impurity-removed liquid; and then organically extracting cobalt, manganese, and nickel from the impurity-removed liquid, wherein the extraction rates of nickel, cobalt, and manganese after extraction are 8%, 24%, and 60%, respectively.

[0135] Although the lithium recovery rate in the steps described in this comparative example can reach 95%, the impurity content is relatively high, and the LiF content is only 10wt%, and subsequent operations such as impurity removal and purification are required. In addition, the extraction and impurity removal are performed by extraction, and the entire process takes 15 hours, while the entire process in Examples 1-4 takes between 11 and 12 hours, which saves 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, and the raffinate needs to be further treated to meet the wastewater discharge standard. The treatment method in this embodiment does not adopt the extraction and impurity removal method for purification and impurity removal. At the same time, the wastewater generated by the entire process is recycled in this process, without any wastewater treatment costs.

[0136] Comparative Example 2:

[0137] A method for short-range recovery of valuable metals from waste ternary lithium batteries, which differs from Example 3 only in that step (5) is omitted and step (6) is adjusted to: heating the solution after the second-stage nickel, cobalt and manganese precipitation to 95°C, adding sodium carbonate solution to precipitate lithium, while maintaining the pH value of the solution at 11.5, and reacting for 5 hours. After the reaction is completed, solid-liquid separation is performed to obtain a lithium carbonate product.

[0138] Comparative Example 3:

[0139] A method for short-range recovery of valuable metals from waste ternary lithium batteries, which differs from Example 3 only in that step (4) is adjusted to: adding sodium hydroxide solution to the liquid after iron and aluminum removal to adjust the pH value to 11.0, and maintaining this pH value for 1 hour. After the reaction is completed, solid-liquid separation is performed to obtain nickel, cobalt and manganese hydroxide and the liquid after nickel, cobalt and manganese precipitation.

[0140] Comparative Example 4:

[0141] A method for short-range recovery of valuable metals from waste ternary lithium batteries, which differs from Example 3 only in that step (4) is adjusted to: adding sodium hydroxide solution to the liquid after iron and aluminum removal to adjust the pH value to 9.0, and maintaining the pH value for 1 hour. After the reaction is completed, solid-liquid separation is performed to obtain a nickel-cobalt-manganese hydroxide product and a liquid after a nickel-cobalt-manganese precipitation.

[0142] The recovery of the main metal elements in the examples and comparative examples herein is shown in the table below. Industrial Applicability

[0143] This scheme can preliminarily classify the obtained nickel cobalt manganese hydroxide products through a two-stage chemical precipitation method. The pH value of the first stage is 8-9, which can precipitate nickel cobalt manganese hydroxide products with relatively high purity. The pH value of the second stage is adjusted to 10-11, and nickel cobalt manganese hydroxide products with relatively high impurity content are precipitated. The scheme is simple to operate, has low production costs and high recovery rates. At the same time, the amount of wastewater generated is extremely small, which reduces wastewater treatment costs and improves production efficiency.

[0144] This solution first precipitates lithium through trisodium phosphate, then converts it through leaching with ferric sulfate to obtain a high-concentration lithium-containing solution, and then uses sodium carbonate to precipitate lithium to obtain a lithium carbonate product with a high main content, achieving efficient lithium recovery. It provides a wet recovery method with a short process and high efficiency for recovering lithium, and overcomes the problem of high impurity content of lithium carbonate in the existing technology, thereby obtaining higher-quality lithium carbonate. Moreover, the entire process is carried out under normal pressure, which is conducive to industrial production.

[0145] Compared with the traditional wet recycling technology of waste ternary lithium batteries, this solution has the advantages of short process flow and low production cost. It eliminates the complex process of using extraction + MVR evaporation crystallization to recover nickel, cobalt and manganese metals and recovering lithium metal after MVR concentration in the traditional process, greatly reducing the energy consumption demand and environmental pollution in the recycling process of waste ternary lithium batteries.

Claims

1. A method for short-range recovery of valuable metals from waste ternary lithium batteries, characterized in that: include: Precipitating nickel, cobalt and manganese, comprising sequentially performing a first stage of nickel, cobalt and manganese precipitation and a second stage of nickel, cobalt and manganese precipitation on the liquid after iron and aluminum removal, and separating the solid and liquid to obtain nickel, cobalt and manganese hydroxide and a liquid after nickel, cobalt and manganese precipitation; wherein the pH value in the first stage of nickel, cobalt and manganese precipitation is 8-9, and the pH value in the second stage of nickel, cobalt and manganese precipitation is 10-11, and the liquid after iron and aluminum removal is obtained by sequentially performing pyrolysis, first stage of reduction leaching, copper removal and iron and aluminum removal on battery black powder; Trisodium phosphate lithium precipitation, using trisodium phosphate to precipitate lithium in the solution after nickel, cobalt and manganese precipitation, and perform solid-liquid separation to obtain lithium phosphate intermediate and sodium salt solution. Lithium phosphate leaching, adding iron salt and a first acid solution to the slurry of the lithium phosphate intermediate to perform leaching, and then performing solid-liquid separation to obtain iron phosphate slag and a lithium salt solution; Lithium carbonate is precipitated, and carbonate is added to the lithium salt solution to obtain lithium carbonate after solid-liquid separation.

2. A method for short-range recovery of valuable metals from waste ternary lithium batteries according to claim 1, characterized in that: The first acid solution is added to the solution after nickel, cobalt and manganese precipitation to adjust the pH value to 8.0-8.5, and then trisodium phosphate is added to precipitate lithium, and the mass of trisodium phosphate added is 1.05-1.15 times the theoretical amount.

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

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

5. A method for short-range recovery of valuable metals from waste ternary lithium batteries according to any one of claims 1 to 4, characterized in that: In the lithium phosphate leaching step, the iron salt is ferric sulfate, and the molar ratio of the lithium phosphate to ferric sulfate is (2.3-2.7):

1.

6. A method for short-range recovery of valuable metals from waste ternary lithium batteries according to any one of claims 1 to 5, characterized in that: In the lithium phosphate leaching step, the first acid solution is sulfuric acid, and the pH value of the solution is adjusted to 2.5-3.5 using the first acid solution.

7. A method for short-range recovery of valuable metals from waste ternary lithium batteries according to any one of claims 1 to 6, characterized in that: In the lithium carbonate precipitation step, the reaction temperature is 80° C.-85° C., and the reaction time is greater than 2 hours.

8. A method for short-range recovery of valuable metals from waste ternary lithium batteries according to any one of claims 1 to 7, characterized in that: In the lithium carbonate precipitation step, the pH value of the solution is first adjusted to 10.5-11.5 and then a water-soluble carbonate is added. The mass of the water-soluble carbonate added is 1.1-1.3 times the theoretical amount.

9. A method for short-range recovery of valuable metals from waste ternary lithium batteries according to any one of claims 1 to 8, characterized in that: The battery black powder is obtained by immersing the ternary lithium battery in salt water for discharge, and then crushing and screening the discharged ternary lithium battery.

10. A method for short-range recovery of valuable metals from waste ternary lithium batteries according to any one of claims 1 to 9, characterized in that: The temperature for pyrolysis of battery black powder is 400°C-600°C, and the pyrolysis time is 1h-3h.

11. A method for short-range recovery of valuable metals from waste ternary lithium batteries according to any one of claims 1 to 10, characterized in that: The first stage reduction leaching is to add water to the battery black powder after pyrolysis for a second slurry, then use the second acid solution to adjust the pH value to 1-2, and introduce the first reducing agent into the slurry for reduction leaching. After the leaching is completed, solid-liquid separation is performed to obtain acid leaching residue and reduction leaching liquid.

12. A method for short-range recovery of valuable metals from waste ternary lithium batteries according to claim 11, characterized in that: The solid-to-liquid ratio of battery black powder to water in the slurry obtained in the second slurrying step is 1:(3-4).

13. A method for short-range recovery of valuable metals from waste ternary lithium batteries according to claim 11 or 12, characterized in that: The second acid solution is sulfuric acid or hydrochloric acid.

14. A method for short-range recovery of valuable metals from waste ternary lithium batteries according to any one of claims 11 to 13, characterized in that: The first reducing agent is sodium pyrosulfite or sulfur dioxide, and the added amount of the first reducing agent 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.

15. A method for short-range recovery of valuable metals from waste ternary lithium batteries according to any one of claims 11 to 14, characterized in that: The time for a reduction leaching step is 1h-2h.

16. A method for short-range recovery of valuable metals from waste ternary lithium batteries according to any one of claims 11 to 15, characterized in that: Also includes: The second stage high acid leaching is to mix the acid leaching residue with water for a third slurrying, and then add the third acid solution for high acid leaching. After the leaching is completed, solid-liquid separation is performed to obtain the second stage high acid leaching residue and the second stage high acid leaching solution.

17. A method for short-range recovery of valuable metals from waste ternary lithium batteries according to claim 16, characterized in that: The second-stage high-acid leaching solution is returned to the first-stage reduction leaching step to be mixed with black powder for slurrying.

18. A method for short-range recovery of valuable metals from waste ternary lithium batteries according to claim 16 or 17, characterized in that: In the third slurrying step, the acid leaching residue and water are slurried at a solid-to-liquid ratio of 1:(3-4).

19. A method for short-range recovery of valuable metals from waste ternary lithium batteries according to any one of claims 16 to 18, characterized in that: The third acid solution is sulfuric acid or hydrochloric acid.

20. A method for short-range recovery of valuable metals from waste ternary lithium batteries according to any one of claims 16 to 19, characterized in that: In the second-stage high-acid leaching step, a third acid solution is added to adjust the slurry hydrogen ion equivalent to 4N.

21. A method for short-range recovery of valuable metals from waste ternary lithium batteries according to any one of claims 16 to 20, characterized in that: The high acid leaching time is 1h-2h.

22. A method for short-range recovery of valuable metals from waste ternary lithium batteries according to any one of claims 11 to 21, characterized in that: The copper removal step comprises adding a second reducing agent to the reduction leaching solution to carry out a copper removal reaction, and after the copper removal reaction is completed, solid-liquid separation is carried out to obtain sponge copper and a copper-removed liquid.

23. A method for short-range recovery of valuable metals from waste ternary lithium batteries according to claim 22, characterized in that: The second reducing agent is iron powder, and the added mass of the iron powder is 1.05-1.15 times of the theoretical amount.

24. A method for short-range recovery of valuable metals from waste ternary lithium batteries according to any one of claims 11 to 23, characterized in that: The reduction leaching solution is further filtered twice, the separated liquid phase enters the copper removal step, and the solid phase is mixed with the acid leaching residue for high acid leaching.

25. A method for short-range recovery of valuable metals from waste ternary lithium batteries according to claim 22 or 23, characterized in that: The step of removing iron and aluminum comprises adding an oxidant to the copper-removed liquid to carry out an iron-removal aluminum reaction, and after the iron-removal aluminum reaction is completed, solid-liquid separation is carried out to obtain iron-aluminum slag and iron-removal aluminum liquid.

26. A method for short-range recovery of valuable metals from waste ternary lithium batteries according to claim 25, 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.

27. A method for short-range recovery of valuable metals from waste ternary lithium batteries according to claim 25 or 26, characterized in that: After the iron and aluminum removal reaction is completed, the pH value is adjusted to 4.5-5.0 and maintained for 30min-60min before solid-liquid separation.

28. A method for short-range recovery of valuable metals from waste ternary lithium batteries according to any one of claims 25 to 27, characterized in that: The one-stage nickel-cobalt-manganese precipitation step comprises adding alkali solution to the iron-aluminum-removed liquid to adjust the pH value to 8-9 and maintaining for 60-90 minutes, and then performing solid-liquid separation to obtain a refined nickel-cobalt-manganese hydroxide product and a one-stage nickel-cobalt-manganese precipitation liquid; The second stage nickel-cobalt-manganese precipitation step includes continuously adding alkali solution to the first stage nickel-cobalt-manganese precipitation liquid to adjust the pH value to 10-11 and maintaining for 60-90 minutes, and then performing solid-liquid separation to obtain a crude nickel-cobalt-manganese hydroxide product and a nickel-cobalt-manganese precipitation liquid.

29. A method for short-range recovery of valuable metals from waste ternary lithium batteries according to claim 28, characterized in that: The alkali solution is an aqueous solution of a strong base.

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