Recovery treatment method based on lithium-extracted battery powder

Abstract

A recovery treatment method based on a lithium-extracted battery powder, which method comprises the following steps: subjecting the battery powder, which has been subjected to lithium extraction, to a pulping operation, so as to obtain a slurry; mixing sulfuric acid, a reducing agent and the slurry, and then subjecting the mixture to a first-section leaching and filtering operation, so as to obtain a first leachate and a first leaching residue; subjecting the first leachate to a P204 extraction and impurity removal operation, so as to obtain a battery-grade nickel-cobalt-manganese solution; mixing sulfuric acid, the reducing agent and the first leaching residue, and then subjecting the mixture to a second-section leaching and filtering operation, so as to obtain a second leachate and a second leaching residue; subjecting the second leachate to an impurity removal and filtration operation, so as obtain a filtrate and a filtering residue; and subjecting the second leaching residue to a high-acid leaching and filtering operation, so as to obtain a battery-grade graphite raw material, wherein the pH value in the first-section leaching and filtering operation is 4-6, and the pH value in the second-section leaching and filtering operation is 1-2.

Description

Recycling method based on lithium battery powder extraction Technical Field

[0001] The present application relates to a recycling method based on the extraction of lithium battery powder. Background Art

[0002] The new energy industry is developing rapidly, and the waste battery recycling industry supporting the new energy industry is growing. However, there are still technical bottlenecks in how to recycle efficiently and greenly.

[0003] Currently, there are two processes for producing battery-grade nickel, cobalt and manganese from lithium battery powder: the pyrometallurgical process and the wet process. The pyrometallurgical process uses a process of prioritizing lithium extraction, drying, smelting, ball milling, leaching and purification. While the pyrometallurgical process consumes a lot of energy and causes significant pollution, its advantage is that after pyrometallurgical impurities removal, only impurities need to be extracted during the purification process to produce a battery-grade nickel, cobalt and manganese solution, saving a significant amount of acid and alkali consumption and saving costs. However, in order to comply with the concept of green recycling, the wet process for producing battery-grade nickel, cobalt and manganese from lithium battery powder generally uses a leaching-impurity removal-extraction-lithium extraction process to treat the battery powder. Most battery powder impurities are removed by adjusting the solution pH with soda ash / calcium carbonate to remove iron and aluminum from the solution. To achieve a better impurity removal effect, the amount of residual acid introduced into the solution during the impurity removal process increases, leading to increased auxiliary material consumption. To ensure the leached nickel-cobalt-manganese solution meets battery-grade standards, the extraction process typically uses P507 for nickel-cobalt extraction. This extraction requires extracting all nickel and cobalt from the leachate into the organic phase, which is then stripped with sulfuric acid or hydrochloric acid. This requires double the amount of hydrogen ions required for stripping, equal to the amount of nickel and cobalt ions present. The organic phase is then saponified with liquid caustic soda, resulting in excessive consumption of auxiliary materials such as sulfuric acid and liquid caustic soda. Furthermore, the full extraction process complicates the entire recovery process. Furthermore, current methods for recycling spent lithium battery powder typically treat the leached residue as solid or hazardous waste. However, the leached residue contains large amounts of graphite, resulting in a waste of graphite resources.

[0004] Therefore, there is an urgent need for a battery powder recovery and processing method with simplified process, low auxiliary material consumption, good impurity removal effect, and the ability to prepare battery-grade nickel-cobalt-manganese solution and battery-grade graphite raw materials.

[0005] Summary of the Invention

[0006] Based on this, it is necessary to provide a recycling method for lithium-ion battery powder that has a simplified process, low auxiliary material consumption, good impurity removal effect, and can prepare battery-grade nickel-cobalt-manganese solution and battery-grade graphite raw materials.

[0007] A recycling method for lithium battery powder, comprising the following steps:

[0008] The battery powder after lithium extraction is subjected to a slurrying operation to obtain a slurry;

[0009] After mixing sulfuric acid, a reducing agent and the slurry, performing a first leaching and filtering operation to obtain a first leachate and a first leach residue;

[0010] The first leachate is subjected to a P204 extraction and impurity removal operation to obtain a battery-grade nickel-cobalt-manganese solution;

[0011] The sulfuric acid, the reducing agent and the first leaching residue are mixed and then subjected to a second leaching and filtering operation to obtain a second leachate and a second leaching residue;

[0012] performing impurity removal and filtration operations on the second leachate to obtain a filtrate and a filter residue;

[0013] performing a high-acid leaching and filtering operation on the second leached residue to obtain a battery-grade graphite raw material;

[0014] Wherein, the pH value in the first stage leaching and filtration operation is 4-6;

[0015] The pH value in the second stage leaching and filtration operation is 1-2.

[0016] The details of one or more embodiments of the present application are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the present application will become apparent from the description, drawings, and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, without paying any creative work, they can also obtain drawings of other embodiments based on these drawings.

[0018] FIG1 is a schematic flow chart of a method for recycling lithium battery powder according to an embodiment;

[0019] FIG2 is a process flow chart of a recycling method based on lithium battery powder extraction. DETAILED DESCRIPTION

[0020] To facilitate understanding of the present application, a more comprehensive description of the present application will be provided below with reference to the accompanying drawings. The accompanying drawings illustrate preferred embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the disclosure of the present application.

[0021] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly attached to the other element or there may be an intermediate element. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only implementation methods.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are intended only to describe specific embodiments and are not intended to limit this application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0023] Referring to FIG1 , a method for recycling battery powder based on lithium extraction according to one embodiment includes some or all of the following steps:

[0024] S100, slurrying the battery powder after lithium extraction to obtain slurry.

[0025] In this embodiment, the lithium extraction slag after lithium extraction is lithium-extracted battery powder, and the battery powder is subjected to a slurrying operation to obtain a slurry to facilitate subsequent recycling and processing.

[0026] S200, sulfuric acid, a reducing agent and the slurry are mixed and then subjected to a first leaching and filtering operation to obtain a first leachate and a first leach residue.

[0027] In this embodiment, the battery powder after lithium extraction primarily contains the metallic elements iron, aluminum, copper, nickel, cobalt, and manganese. A first leaching and filtration operation is performed in a leaching tank after mixing sulfuric acid, a reducing agent, and a slurry. The pH value of the first leaching and filtration operation is controlled between 4 and 6. At a pH between 4 and 6 and under the action of the reducing agent, the metallic elements iron, aluminum, and copper readily precipitate. This allows nickel, cobalt, and manganese to be separated from iron, aluminum, and copper, facilitating the recovery of the metallic elements nickel, cobalt, and manganese.

[0028] S300, performing a P204 extraction and impurity removal operation on the first leachate to obtain a battery-grade nickel-cobalt-manganese solution.

[0029] In this embodiment, the battery powder after lithium extraction is doped with calcium, which is incorporated into the first leachate after the first leaching and filtration operation. Due to the excellent calcium ion extraction performance of the P204 extractant, the calcium ions in the first leachate are extracted by adding the P204 extractant to remove impurities from the first leachate to obtain a battery-grade nickel-cobalt-manganese solution. Therefore, there is no need to perform a full extraction process on the leachate, effectively reducing the consumption of auxiliary materials. This also significantly simplifies the preparation method of the battery-grade nickel-cobalt-manganese solution, thereby simplifying the recovery and processing steps of the lithium-extracted battery powder.

[0030] Furthermore, by designing a treatment method for battery powder to first extract lithium and then recycle it, there is no need to additionally extract lithium ions when preparing battery-grade nickel-cobalt-manganese solution, which can further simplify the preparation process of battery-grade nickel-cobalt-manganese solution.

[0031] It should also be noted that the content of nickel + cobalt + manganese is 100g / L to 120g / L, which is battery-grade nickel-cobalt-manganese solution.

[0032] S400: mixing the sulfuric acid, the reducing agent and the first leaching residue, and performing a second leaching and filtering operation to obtain a second leachate and a second leaching residue.

[0033] In this embodiment, sulfuric acid, a reducing agent, and the first leaching residue are mixed and then a second leaching and filtration operation is performed in a second-stage leaching tank. At the same time, the pH value of the second leaching and filtration operation is controlled at 1-2. A second leaching residue is formed under the action of the reducing agent at a pH value of 1-2, and the iron, aluminum, and copper elements in the first leaching residue are leached to form a second leachate, thereby recovering the iron, aluminum, and copper elements.

[0034] S500, performing impurity removal and filtration operations on the second leachate to obtain a filtrate and a filter residue.

[0035] In this embodiment, the second leachate is subjected to impurity removal and filtration operations, and the filtered residue is iron-aluminum-copper residue, thereby realizing the recovery of iron, aluminum and copper elements.

[0036] S600: performing high-acid leaching and filtering operations on the second leached residue to obtain battery-grade graphite raw material.

[0037] In this embodiment, since the second leaching residue is rich in graphite, battery-grade graphite raw materials can be obtained by performing high-acid leaching and filtration operations on the second leaching residue, thereby realizing the recycling and reuse of graphite, while saving the cost of disposing the second leaching residue as solid waste or hazardous waste.

[0038] It should be noted that battery-grade graphite raw materials only need to be graphitized once to obtain battery-grade graphite, and battery-grade graphite raw materials can only be obtained when the nickel, cobalt and manganese content in the leached residue is less than 0.08%, and there is no need for secondary impurity removal.

[0039] It should also be noted that high acid here refers to acid with an acidity of more than 100 g / L, while the acidity of the first-stage filtration operation and the second-stage filtration operation are both below 100 g / L.

[0040] The pH value in the first leaching and filtration operation is 4-6; the pH value in the second leaching and filtration operation is 1-2.

[0041] The above-mentioned recovery and treatment method based on lithium battery powder extraction is to mix sulfuric acid, a reducing agent and a slurry and then perform a first leaching and filtration operation. At the same time, the pH value is strictly controlled between 4 and 6. Under the action of the reducing agent, the iron, aluminum and copper elements in the battery powder after lithium extraction are formed into a precipitate, namely the first leaching residue. The first leaching residue and the first leachate are separated by filtration, and the first leachate is then subjected to a P204 extraction and impurity removal operation, that is, the calcium ions in the first leachate are extracted and impurities are removed by the P204 extractant, thereby preparing a battery-grade nickel-cobalt-manganese solution. Therefore, the preparation of the battery-grade nickel-cobalt-manganese solution can be completed without a full extraction process, which can effectively reduce the consumption of auxiliary materials and greatly simplify the preparation method of the battery-grade nickel-cobalt-manganese solution, thereby simplifying the recovery and treatment steps of the lithium battery powder, thereby effectively improving the recovery and treatment efficiency of the lithium battery powder and reducing the recovery and treatment cost of the lithium battery powder.

[0042] Furthermore, after mixing sulfuric acid, a reducing agent, and the first leaching residue, a second leaching and filtration operation is performed. At the same time, the pH value is strictly controlled between 1 and 2, and a second leaching residue is formed under the action of the reducing agent. At the same time, the iron, aluminum, and copper elements in the first leaching residue are leached and a second leachate is formed. The second leaching residue and the second leachate are separated by filtration. Then, the second leachate is subjected to an impurity removal and filtration operation to obtain a filter residue, which is a mixed precipitate of iron, aluminum, and copper, thereby achieving a good impurity removal and recovery effect. Furthermore, since the second leaching residue is rich in graphite, by performing a high-acid leaching and filtration operation on the second leaching residue, battery-grade graphite raw material can be obtained, realizing the recycling and reuse of graphite, while saving the cost of disposing the second leaching residue as solid waste or hazardous waste.

[0043] In one embodiment, the lithium-extracted battery powder is slurried to obtain a slurry, and the specific operation steps are: adding pure water to the lithium-extracted battery powder to perform a slurrying operation to obtain the slurry having a solid content of 20% to 30%. It should be noted that the lithium-extracted battery powder is slurried with pure water to obtain a slurry having a solid content of 20% to 30%.

[0044] In one embodiment, after subjecting the first leachate to a P204 extraction and impurity removal operation to obtain a battery-grade nickel-cobalt-manganese solution, and before subjecting the sulfuric acid, the reducing agent, and the first leach residue to a second-stage leaching and filtration operation to obtain a second leachate and a second leach residue, the recovery method further includes the step of dissolving the first leach residue. It should be noted that the first leach residue obtained by filtration must first be formed into a liquid form, and then dissolved by adding pure water to facilitate the subsequent second-stage leaching and filtration operation.

[0045] In one embodiment, after the step of dissolving the first leaching residue and before the step of subjecting the first leachate to a P204 extraction and impurity removal operation to obtain a battery-grade nickel-cobalt-manganese solution, the recovery method further includes the following steps:

[0046] performing a content detection operation on the dissolved first leaching residue;

[0047] The content of the first leaching residue is judged as follows:

[0048] When the mass percentage of the iron and aluminum content in the first leaching residue is greater than or equal to 5%, the sulfuric acid, the reducing agent and the first leaching residue are mixed and then a second leaching and filtering operation is performed;

[0049] When the mass percentage of the iron and aluminum content in the first leaching residue is less than 5%, the sulfuric acid, the reducing agent, the first leaching residue and the slurry are mixed and then a first stage leaching and filtering operation is performed.

[0050] It should be noted that by detecting the iron and aluminum content of the first leaching residue, the impurity content in the first leaching residue can be obtained. When the mass percentage of the impurity content is less than 5%, the first leaching residue is returned to the first leaching tank and the first leaching and filtration operation is circulated, which can effectively increase the impurity content in the second leachate, facilitate impurity removal, and reduce the waste of auxiliary materials for multiple impurity removal, thereby effectively reducing the use of impurity removal auxiliary materials, and further effectively reducing the recycling and processing costs of lithium battery powder.

[0051] In one embodiment, the first leachate is subjected to a P204 extraction and impurity removal operation to obtain a battery-grade nickel-cobalt-manganese solution in the following specific steps:

[0052] P204 extractant is added to the first leachate and then an extraction operation is performed to obtain the battery-grade nickel-cobalt-manganese solution.

[0053] It should be noted that by extracting other impurity ions in the first leachate into the P204 extractant, a better impurity removal effect can be achieved, and battery-grade nickel-cobalt-manganese solution can also be prepared.

[0054] In one embodiment, the specific steps of performing impurity removal and filtration operation on the second leachate are:

[0055] adding active metals to the second leachate to perform copper removal;

[0056] An alkaline salt is added to the second leachate after copper removal to perform a filtration operation to obtain a filter residue and a filtrate.

[0057] It should be noted that copper ions in the second leachate can be replaced by adding active metals to the second leachate for copper replacement. Alkaline salts are then added to adjust the pH of the second leachate to between 3 and 4, allowing both iron and aluminum to form corresponding metal salt precipitates. Filtration is then performed to obtain a filter residue and a filtrate, wherein the filter residue is an iron-aluminum-copper slag, thereby effectively recovering the iron, aluminum, and copper metal elements.

[0058] In one embodiment, the active metal is one of iron powder, manganese powder or nickel powder. It should be noted that according to the metal activity ranking table, the copper ions in the second leachate can be replaced by selecting an active metal with a greater activity than copper.

[0059] In one embodiment, the alkaline salt is industrial-grade sodium carbonate or industrial-grade sodium hydroxide. It should be noted that the use of high-purity raw materials such as industrial-grade sodium carbonate and industrial-grade sodium hydroxide as alkaline salts can effectively reduce the incorporation of impurities, thereby reducing the use of impurity removal auxiliary materials, and further effectively reducing the recycling and processing costs of lithium battery powder.

[0060] In one embodiment, the specific steps of performing high acid leaching and filtering operation on the second leaching residue to obtain battery-grade graphite raw material are as follows:

[0061] The sulfuric acid, the reducing agent and the second leaching residue are mixed and then subjected to a first high-acid leaching and filtering operation to obtain a first high-acid leaching residue and a first high-acid leaching liquid;

[0062] The sulfuric acid, the reducing agent and the first high-acid leaching residue are mixed and then subjected to a second high-acid leaching and filtering operation to obtain the battery-grade graphite raw material.

[0063] It should be noted that the metal content in the second leaching residue after the first and second leaching and filtration operations is relatively low. To meet the leaching requirements of battery-grade graphite raw materials, the metal in the second leaching residue is first leached through a first high-acid leaching and filtration operation, using a high-acid leaching method with an acidity greater than 100 g / L. That is, by increasing the acidity of the sulfuric acid, the number of back-and-forth collisions between the sulfuric acid and the metal to be leached in the second leaching residue is increased, allowing the metal to be leached in the second leaching residue to dissolve in the sulfuric acid, thereby effectively reducing the metal content in the first high-acid leaching residue. Secondly, the metal content in the first high-acid leaching residue after the first high-acid leaching filtration operation is lower than the metal content in the second leaching residue. By setting the acidity of the second high-acid leaching filtration operation to be greater than the acidity of the first high-acid leaching filtration operation, that is, further increasing the acidity of the sulfuric acid, thereby further increasing the number of back-and-forth collisions between the sulfuric acid and the metal to be leached in the first high-acid leaching residue, the metal to be leached in the first high-acid leaching residue can be dissolved in the sulfuric acid, thereby enabling the second high-acid leaching residue to meet the standards of battery-grade graphite raw materials.

[0064] In one embodiment, after mixing the sulfuric acid, the reducing agent, and the second leaching residue and performing a first high-acid leaching and filtration operation to obtain the first high-acid leaching residue and the first high-acid leachate, the recovery and treatment method further includes the following steps: mixing the sulfuric acid, the reducing agent, the first high-acid leachate, and the first leaching residue and performing a second leaching and filtration operation. It should be noted that by returning the first high-acid leachate to the second-stage leaching tank, the amount of sulfuric acid added in the second-stage leaching and filtration operation can be reduced, enabling the recovery and reuse of auxiliary materials, thereby effectively reducing the consumption of auxiliary materials and, in turn, effectively reducing the recovery and treatment costs of lithium battery powder.

[0065] In one embodiment, after mixing the sulfuric acid, the reducing agent, and the first high-acid leaching residue and then performing a second high-acid leaching and filtering operation to obtain the battery-grade graphite raw material, the recovery method further includes the following steps: mixing the sulfuric acid, the reducing agent, the second high-acid leaching solution, and the second leaching residue and then performing a first high-acid leaching and filtering operation. It should be noted that by returning the second high-acid leaching solution to the first high-acid leaching tank, the amount of sulfuric acid added in the first high-acid leaching and filtering operation can be reduced, enabling the recovery and reuse of auxiliary materials, thereby effectively reducing the consumption of auxiliary materials and, in turn, effectively reducing the recovery and processing costs of lithium battery powder.

[0066] In one embodiment, the acidity of the first high-acid leaching and filtration operation is 200 g / L to 300 g / L. It is understood that at an acidity of 200 g / L to 300 g / L, the number of back-and-forth collisions between the sulfuric acid and the metal to be leached in the second leaching residue can be increased, allowing the metal to be dissolved in the sulfuric acid, i.e., leaching the metal in the second leaching residue into the first high-acid leachate.

[0067] In one embodiment, the acidity of the second high-acid leaching and filtration operation is 300 g / L to 500 g / L. It is understood that at an acidity of 300 g / L to 500 g / L, the number of back-and-forth collisions between sulfuric acid and the metal to be leached in the first high-acid leaching residue can be further increased, further dissolving the metal to be leached in the sulfuric acid, allowing the second high-acid leaching residue to meet the standards of battery-grade graphite raw materials. This not only saves the cost of disposing the leaching residue as hazardous waste or solid waste, but also enables the recycling of graphite.

[0068] In one embodiment, the temperature of the first high-acid leaching and filtration operation and the second high-acid leaching and filtration operation are both 80° C. to 100° C. It can be understood that at a temperature of 80° C. to 100° C., the first high-acid leaching and filtration operation and the second high-acid leaching and filtration operation can both leach the metals in the leached residue to the greatest extent, thereby achieving a better impurity removal effect.

[0069] In one embodiment, the temperature of the first leaching and filtration operation is 80°C to 100°C. It should be noted that when the temperature is 80°C to 100°C and the pH value is strictly controlled between 4 and 6, the impurity content of iron, aluminum, copper, etc. in the first leachate is less than 2ppm. That is, when the impurity content is less than 2ppm, the first leachate can meet the requirements of P204 extraction without further impurity removal. The first leachate is subjected to extraction and impurity removal operation by the P204 extractant, so that a battery-grade nickel-cobalt-manganese solution can be obtained. Therefore, a battery-grade nickel-cobalt-manganese solution can be prepared without a full extraction process, which can greatly simplify the preparation process of the battery-grade nickel-cobalt-manganese solution, thereby simplifying the recovery and processing steps of the lithium battery powder, and further improving the recovery and processing efficiency of the lithium battery powder.

[0070] In one embodiment, the reducing agent is at least one of hydrogen peroxide, sulfur dioxide, and sodium sulfite. It should be noted that the addition of the reducing agent reduces the metal elements, such as iron, aluminum, copper, nickel, cobalt, and manganese, in the lithium battery powder to corresponding metal ions, facilitating impurity removal and recovery.

[0071] Examples are listed below, but it should be noted that the following examples do not exhaust all possible situations, and the materials used in the following examples can be obtained from commercial channels unless otherwise specified.

[0072] Example 1

[0073] Pure water is added to the extracted lithium battery powder to obtain a slurry with a solid content of 20%. Sulfuric acid, a reducing agent, and the slurry are mixed and the pH is adjusted to 4.3, followed by a first leaching and filtration operation to obtain a first leachate and a first leach residue. The first leachate is subjected to a P204 extraction and impurity removal operation to obtain a battery-grade nickel-cobalt-manganese solution. Sulfuric acid, a reducing agent, and the first leach residue are mixed and the pH is adjusted to 1.5, followed by a second leaching and filtration operation to obtain a second leachate and a second leach residue. The second leachate is subjected to an impurity removal and filtration operation to obtain a filtrate and a filter residue. The second leach residue is subjected to a high-acid leaching and filtration operation to obtain a battery-grade graphite raw material.

[0074] The first leachate is shown in Table 1:

[0075] The first leachate after P204 extraction and impurity removal is shown in Table 2:

[0076] After the first leaching residue was circulated for three times in the first stage leaching and filtration operation, the second leachate obtained by the second stage leaching and filtration operation was shown in Table 3:

[0077] The second highest acid leaching residue (battery-grade graphite raw material) is shown in Table 4:

[0078] Example 2

[0079] Pure water is added to the extracted lithium battery powder to obtain a slurry with a solid content of 20%. Sulfuric acid, a reducing agent, and the slurry are mixed and the pH is adjusted to 4.8 before a first leaching and filtration operation is performed to obtain a first leachate and a first leach residue. The first leachate is subjected to a P204 extraction and impurity removal operation to obtain a battery-grade nickel-cobalt-manganese solution. Sulfuric acid, a reducing agent, and the first leach residue are mixed and the pH is adjusted to 1.5 before a second leaching and filtration operation is performed to obtain a second leachate and a second leach residue. The second leachate is subjected to an impurity removal and filtration operation to obtain a filtrate and a filter residue. The second leach residue is subjected to a high-acid leaching and filtration operation to obtain a battery-grade graphite raw material.

[0080] The element content of the first leachate is shown in Table 5:

[0081] The element content of the raffinate after P204 extraction and impurity removal is shown in Table 6:

[0082] After the first leaching residue was recycled for three times in the first leaching and filtration operation, the element content of the second leachate obtained by the second leaching and filtration operation was shown in Table 7:

[0083] The element content of the second highest acid leaching residue (battery-grade graphite raw material) is shown in Table 8:

[0084] Example 3

[0085] Prepare 180g / L sulfuric acid solution. Add pure water to the lithium battery powder to obtain a slurry with a solid content of 20%. Mix the sulfuric acid, reducing agent and slurry and adjust the pH value to 5.2, then perform the first leaching and filtration operation to obtain the first leachate and the first leach residue. Perform a P204 extraction and impurity removal operation on the first leachate to obtain a battery-grade nickel-cobalt-manganese solution. Mix the sulfuric acid, reducing agent and the first leach residue and adjust the pH to 1.5, then perform a second leaching and filtration operation to obtain the second leachate and the second leach residue. Perform an impurity removal and filtration operation on the second leachate to obtain a filtrate and a filter residue. Perform a high-acid leaching and filtration operation on the second leach residue to obtain battery-grade graphite raw material.

[0086] The element content of the first leachate is shown in Table 9:

[0087] The element content of the raffinate after P204 extraction and impurity removal is shown in Table 10:

[0088] After the first leaching residue was recycled for three times in the first leaching and filtration operation, the element content of the second leachate obtained by the second leaching and filtration operation was shown in Table 11:

[0089] The element content of the second highest acid leaching residue (battery-grade graphite raw material) is shown in Table 12:

[0090] Example 4

[0091] Pure water is added to the lithium battery powder to obtain a slurry with a solid content of 20%. Sulfuric acid, a reducing agent, and the slurry are mixed and the pH is adjusted to 5.7 before a first leaching and filtration operation is performed to obtain a first leachate and a first leach residue. The first leachate is subjected to a P204 extraction and impurity removal operation to obtain a battery-grade nickel-cobalt-manganese solution. Sulfuric acid, a reducing agent, and the first leach residue are mixed and the pH is adjusted to 1.5 before a second leaching and filtration operation is performed to obtain a second leachate and a second leach residue. The second leachate is subjected to an impurity removal and filtration operation to obtain a filtrate and a filter residue. The second leach residue is subjected to a high-acid leaching and filtration operation to obtain a battery-grade graphite raw material.

[0092] The element contents of the first leachate are shown in Table 13:

[0093] The element content of the raffinate after P204 extraction and impurity removal is shown in Table 14:

[0094] After the first leaching residue was recycled for three times in the first leaching and filtration operation, the element contents of the second leachate obtained by the second leaching and filtration operation were shown in Table 15:

[0095] The element content of the second highest acid leaching residue (battery-grade graphite raw material) is shown in Table 16:

[0096] Example 5

[0097] Pure water is added to the lithium battery powder to obtain a slurry with a solid content of 20%. Sulfuric acid, a reducing agent, and the slurry are mixed and the pH is adjusted to 6.0, followed by a first leaching and filtration operation to obtain a first leachate and a first leach residue. The first leachate is subjected to a P204 extraction and impurity removal operation to obtain a battery-grade nickel-cobalt-manganese solution. Sulfuric acid, a reducing agent, and the first leach residue are mixed and the pH is adjusted to 1.5, followed by a second leaching and filtration operation to obtain a second leachate and a second leach residue. The second leachate is subjected to an impurity removal and filtration operation to obtain a filtrate and a filter residue. The second leach residue is subjected to a high-acid leaching and filtration operation to obtain a battery-grade graphite raw material.

[0098] The element contents of the first leachate are shown in Table 17:

[0099] The element content of the raffinate after P204 extraction and impurity removal is shown in Table 18:

[0100] After the first leaching residue was recycled three times for the first leaching and filtration operation, the element content of the second leachate obtained by the second leaching and filtration operation was shown in Table 19:

[0101] The element content of the second highest acid leaching residue (battery-grade graphite raw material) is shown in Table 20:

[0102] Example 6

[0103] Pure water is added to the extracted lithium battery powder to obtain a slurry with a solid content of 20%. Sulfuric acid, a reducing agent, and the slurry are mixed and the pH is adjusted to 4.0, followed by a first leaching and filtration operation to obtain a first leachate and a first leach residue. The first leachate is subjected to a P204 extraction and impurity removal operation to obtain a battery-grade nickel-cobalt-manganese solution. Sulfuric acid, a reducing agent, and the first leach residue are mixed and the pH is adjusted to 1.5, followed by a second leaching and filtration operation to obtain a second leachate and a second leach residue. The second leachate is subjected to an impurity removal and filtration operation to obtain a filtrate and a filter residue. The second leach residue is subjected to a high-acid leaching and filtration operation to obtain battery-grade graphite raw material.

[0104] The element content of the first leachate is shown in Table 21:

[0105] The element content of the raffinate after P204 extraction and impurity removal is shown in Table 22:

[0106] After the first leaching residue was recycled three times for the first leaching and filtration operation, the element content of the second leachate obtained by the second leaching and filtration operation was shown in Table 23:

[0107] The element content of the second highest acid leaching residue (battery-grade graphite raw material) is shown in Table 24:

[0108] Comparative Example 1

[0109] Pure water is added to the extracted lithium battery powder to obtain a slurry with a solid content of 20%. Sulfuric acid, a reducing agent, and the slurry are mixed and the pH is adjusted to 2.0, followed by a first leaching and filtration operation to obtain a first leachate and a first leach residue. The first leachate is subjected to a P204 extraction and impurity removal operation to obtain a battery-grade nickel-cobalt-manganese solution. Sulfuric acid, a reducing agent, and the first leach residue are mixed and the pH is adjusted to 1.5, followed by a second leaching and filtration operation to obtain a second leachate and a second leach residue. The second leachate is subjected to an impurity removal and filtration operation to obtain a filtrate and a filter residue. The second leach residue is subjected to a high-acid leaching and filtration operation to obtain battery-grade graphite raw material.

[0110] The element contents of the first leachate are shown in Table 25:

[0111] The element content of the raffinate after P204 extraction and impurity removal is shown in Table 26:

[0112] After the first leaching residue was recycled three times for the first leaching and filtration operation, the element content of the second leachate obtained by the second leaching and filtration operation was shown in Table 27:

[0113] The element content of the second highest acid leaching residue (battery-grade graphite raw material) is shown in Table 28:

[0114] Comparative Example 2

[0115] Pure water is added to the extracted lithium battery powder to obtain a slurry with a solid content of 20%. Sulfuric acid, a reducing agent, and the slurry are mixed and the pH is adjusted to 2.5 before a first leaching and filtration operation is performed to obtain a first leachate and a first leach residue. The first leachate is subjected to a P204 extraction and impurity removal operation to obtain a battery-grade nickel-cobalt-manganese solution. Sulfuric acid, a reducing agent, and the first leach residue are mixed and the pH is adjusted to 1.5 before a second leaching and filtration operation is performed to obtain a second leachate and a second leach residue. The second leachate is subjected to an impurity removal and filtration operation to obtain a filtrate and a filter residue. The second leach residue is subjected to a high-acid leaching and filtration operation to obtain a battery-grade graphite raw material.

[0116] The element contents of the first leachate are shown in Table 29:

[0117] The element content of the raffinate after P204 extraction and impurity removal is shown in Table 30:

[0118] After the first leaching residue was recycled three times for the first leaching and filtration operation, the element content of the second leachate obtained by the second leaching and filtration operation was shown in Table 31:

[0119] The element content of the second highest acid leaching residue (battery-grade graphite raw material) is shown in Table 32:

[0120] Comparative Example 3

[0121] Pure water is added to the extracted lithium battery powder to obtain a slurry with a solid content of 20%. Sulfuric acid, a reducing agent, and the slurry are mixed and the pH is adjusted to 3.0, followed by a first leaching and filtration operation to obtain a first leachate and a first leach residue. The first leachate is subjected to a P204 extraction and impurity removal operation to obtain a battery-grade nickel-cobalt-manganese solution. Sulfuric acid, a reducing agent, and the first leach residue are mixed and the pH is adjusted to 1.5, followed by a second leaching and filtration operation to obtain a second leachate and a second leach residue. The second leachate is subjected to an impurity removal and filtration operation to obtain a filtrate and a filter residue. The second leach residue is subjected to a high-acid leaching and filtration operation to obtain a battery-grade graphite raw material.

[0122] The element contents of the first leachate are shown in Table 33:

[0123] The element content of the raffinate after P204 extraction and impurity removal is shown in Table 34:

[0124] After the first leaching residue was recycled three times for the first leaching and filtration operation, the element content of the second leachate obtained by the second leaching and filtration operation was shown in Table 35:

[0125] The element content of the second highest acid leaching residue (battery-grade graphite raw material) is shown in Table 36:

[0126] Tables 1 to 36 show that when the pH value of the first leaching and filtration operation is not between 4 and 6, the iron, aluminum, and copper contents in the first leachate increase significantly, resulting in the raffinate after P204 extraction and impurity removal failing to meet battery-grade nickel, cobalt, and manganese requirements. This demonstrates that strictly controlling the pH value between 4 and 6 during the first leaching and filtration operation reduces the iron, aluminum, and copper contents in the first leachate, and ensures that the raffinate after P204 extraction and impurity removal meets battery-grade nickel, cobalt, and manganese requirements. This not only significantly simplifies the battery-grade nickel, cobalt, and manganese recovery process, but also reduces the consumption of auxiliary materials. It also streamlines the lithium battery powder recovery process, aligning with the concept of green recycling. Furthermore, the leached residues after both the first and second high-acid leaching and filtration operations meet the standards for battery-grade graphite raw materials. This demonstrates that the implementation of the first and second high-acid leaching and filtration operations not only enables the recovery of battery-grade graphite raw materials but also reduces the cost of disposing the leached residue as hazardous or solid waste.

[0127] Compared with the prior art, this application has at least the following advantages:

[0128] 1. The recycling and processing method based on lithium battery powder extraction of the present application is to mix sulfuric acid, a reducing agent and a slurry and then perform a first leaching and filtering operation. At the same time, the pH value is strictly controlled between 4-6 and under the action of the reducing agent, so that the iron, aluminum and copper elements in the battery powder after lithium extraction form a precipitate, namely the first leaching residue. The first leaching residue and the first leachate are separated by filtration, and then the first leachate is subjected to a P204 extraction and impurity removal operation, that is, the calcium ions in the first leachate are extracted and impurities are removed by the P204 extractant, so that a battery-grade nickel-cobalt-manganese solution can be prepared. Therefore, the preparation of the battery-grade nickel-cobalt-manganese solution can be completed without a full extraction process, which can effectively reduce the consumption of auxiliary materials and greatly simplify the preparation method of the battery-grade nickel-cobalt-manganese solution, thereby simplifying the recycling and processing steps of the lithium battery powder, thereby effectively improving the recycling and processing efficiency of the lithium battery powder and reducing the recycling and processing cost of the lithium battery powder.

[0129] 2. The recycling and treatment method based on lithium battery powder extraction of the present application is to mix sulfuric acid, a reducing agent and a first leaching residue and then perform a second leaching and filtering operation. At the same time, the pH value is strictly controlled between 1-2 and a second leaching residue is formed under the action of the reducing agent. At the same time, the iron, aluminum and copper elements in the first leaching residue are leached and a second leachate is formed. The second leaching residue and the second leachate are separated by filtration. The second leachate is then subjected to an impurity removal and filtration operation to obtain a filter residue, which is a mixed precipitate of iron, aluminum and copper, thereby achieving a better impurity removal and recovery effect. Furthermore, since the second leaching residue is rich in graphite, by performing a high-acid leaching and filtration operation on the second leaching residue, battery-grade graphite raw materials can be obtained, thereby realizing the recycling and reuse of graphite and saving the cost of disposing of the second leaching residue as solid waste or hazardous waste.

[0130] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0131] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art could make various modifications and improvements without departing from the spirit of the present application, all of which fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A recycling method based on lithium battery powder extraction, characterized in that: The following steps are involved: The battery powder after lithium extraction is subjected to slurrying operation to obtain slurry; After mixing sulfuric acid, a reducing agent and the slurry, a first leaching and filtering operation is performed to obtain a first leaching solution and a first leaching residue; The first leaching solution is subjected to a P204 extraction and impurity removal operation to obtain a battery-grade nickel-cobalt-manganese solution. The sulfuric acid, the reducing agent and the first leaching residue are mixed and then subjected to a second leaching and filtering operation to obtain a second leaching solution and a second leaching residue; performing impurity removal and filtration operations on the second leachate to obtain a filtrate and a filtrate residue; Wherein, the pH value in the first stage of leaching and filtration operation is 4-6; The pH value in the second stage leaching and filtration operation is 1-2.

2. The recycling method based on lithium battery powder extraction according to claim 1 is characterized in that: The specific steps for slurrying the lithium battery powder are as follows: Pure water is added to the lithium battery powder to perform slurrying operation to obtain the slurry with a solid content of 20% to 30%.

3. The recycling method based on lithium battery powder extraction according to claim 1 is characterized in that: After the step of subjecting the first leachate to a P204 extraction and impurity removal operation, and before the step of subjecting the sulfuric acid, the reducing agent and the first leaching residue to a second leaching and filtering operation, the recovery method further comprises the following steps: The first leaching residue is subjected to a dissolving operation.

4. The recycling method based on lithium battery powder according to claim 3 is characterized in that: After the step of dissolving the first leaching residue and before the step of extracting and removing impurities with P204 on the first leaching solution, the recovery method further comprises the following steps: Performing a content detection operation on the dissolved first leaching residue; The content result of the first leached residue is judged, and the specific judgment operation is as follows: When the mass percentage of the iron and aluminum content in the first leaching residue is greater than or equal to 5%, the sulfuric acid, the reducing agent and the first leaching residue are mixed and then a second leaching and filtering operation is performed; When the mass percentage of the iron and aluminum content in the first leaching residue is less than 5%, the sulfuric acid, the reducing agent, the first leaching residue and the slurry are mixed and then a first stage leaching and filtering operation is performed.

5. The recycling method based on lithium battery powder extraction according to claim 1 is characterized in that: The specific operation steps of subjecting the first leachate to P204 extraction and impurity removal operation to obtain a battery-grade nickel-cobalt-manganese solution are as follows: After adding P204 extractant to the first leaching solution, an extraction operation is performed to obtain the battery-grade nickel-cobalt-manganese solution.

6. The recycling method based on lithium battery powder extraction according to claim 1 is characterized in that: The specific operation steps of performing impurity removal and filtration operation on the second leachate are: adding active metals to the second leaching solution to perform copper removal operation; After copper removal, an alkaline salt is added to the second leaching solution to perform filtering operation to obtain filter residue and filtrate.

7. The recycling method based on lithium battery powder according to claim 6 is characterized in that: The active metal is one of iron powder, manganese powder or nickel powder.

8. The recycling method based on lithium battery powder extraction according to claim 6 is characterized in that: The alkaline salt is industrial grade sodium carbonate or industrial grade sodium hydroxide.

9. The recycling method based on lithium battery powder extraction according to claim 1 is characterized in that: The specific operation steps of performing high acid leaching and filtering operation on the second leaching residue are: The sulfuric acid, the reducing agent and the second leaching residue are mixed and then subjected to a first high-acid leaching filtration operation to obtain a first high-acid leaching residue and a first high-acid leaching solution; The sulfuric acid, the reducing agent and the first high-acid leaching residue are mixed and then subjected to a second high-acid leaching filtration operation to obtain the battery-grade graphite raw material.

10. The recycling method based on lithium battery powder extraction according to claim 9 is characterized in that: After the step of mixing the sulfuric acid, the reducing agent and the second leaching residue and then performing a first high-acid leaching filtration operation, and before the step of mixing the sulfuric acid, the reducing agent and the first high-acid leaching residue and then performing a second high-acid leaching filtration operation, the recovery method further includes the following steps: The sulfuric acid, the reducing agent, the first high-acid leaching solution and the first leaching residue are mixed and then subjected to a second stage leaching and filtering operation.

11. The recycling method based on lithium battery powder extraction according to claim 9, characterized in that: After the step of mixing the sulfuric acid, the reducing agent and the first high-acid leaching residue and performing a second high-acid leaching filtration operation to obtain the battery-grade graphite raw material, the recycling method further comprises the following steps: The sulfuric acid, the reducing agent, the second high-acid leaching solution and the second leaching residue are mixed and then subjected to a first high-acid leaching filtration operation.

12. The recycling method based on lithium battery powder extraction according to claim 9, characterized in that: The acidity of the first high-acid leaching and filtering operation is 200 g / L to 300 g / L.

13. The recycling method based on lithium battery powder according to claim 9, characterized in that: The acidity of the first high-acid leaching and filtering operation is 300 g / L to 500 g / L.

14. The recycling method based on lithium battery powder according to claim 9, characterized in that: The temperature of the first high acid leaching and filtering operation and the second high acid leaching and filtering operation are both 80°C to 100°C.

15. The recycling method based on lithium battery powder extraction according to claim 1, characterized in that: The temperature of the first stage leaching and filtering operation is 80°C to 100°C.

16. The recycling method based on lithium battery powder extraction according to claim 1, characterized in that: The reducing agent is at least one of hydrogen peroxide, sulfur dioxide and sodium sulfite.

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