WO2021134517A1

WO2021134517A1 - Method for comprehensive extraction of metals from spent lithium-ion batteries

Info

Publication number: WO2021134517A1
Application number: PCT/CN2019/130635
Authority: WO
Inventors: 许开华; 蒋振康; 李琴香; 张坤; 王文杰; 王峻; 温世红
Original assignee: 荆门市格林美新材料有限公司; 格林美股份有限公司
Priority date: 2019-12-30
Filing date: 2019-12-31
Publication date: 2021-07-08
Also published as: CN111041218A

Abstract

Disclosed is a method for the comprehensive extraction of metals from spent lithium-ion batteries. The steps of the method comprise, in sequence, acid dissolution (S1), alkalization and impurity removal (S2), extraction 1 (S3), extraction 2 (S4), extraction 3 (S5), electrodeposition (S6), purification and refinement (S7), and purification and preparation (S8). A raffinate 1 and a copper sulfate solution are obtained by means of the extraction 1 (S3) step, and the copper sulfate solution is subjected to the electrodeposition (S6) to obtain negative electrode copper; the raffinate 1 is subjected to the extraction 2 (S4) step to obtain a raffinate 2 and a manganese sulfate solution, and the manganese sulfate solution is subjected to the refinement (S7) to obtain a battery-grade manganese sulfate solution; and the raffinate 2 is subjected to the extraction 3 (S5) step to obtain a raffinate 3 and a battery-grade Ni-Co mixed solution, and the raffinate 3 is subjected to the purification and preparation (S8) to obtain battery-grade lithium carbonate. By means of the three extractions stage by stage, the copper, battery-grade Ni-Co mixed solution, battery-grade manganese sulfate solution and battery-grade lithium carbonate are recovered in sequence, thereby achieving the comprehensive recovery of multiple metal elements from spent lithium-ion batteries and increasing the overall metal recovery rate.

Description

Method for comprehensively extracting metals from waste lithium ion batteries

Technical field

The invention relates to the field of lithium ion batteries, in particular to a method for comprehensively extracting metals from waste lithium ion batteries.

Background technique

Lithium-ion batteries are widely used in many fields such as mobile phones, notebook computers and new energy vehicles due to their own advantages such as high specific capacitance, excellent cycleability, light weight and portability. At present, the most widely used power lithium ion at home and abroad The battery system is mainly lithium iron phosphate and ternary systems, such as nickel-manganese-cobalt or nickel-cobalt-aluminum battery systems composed of three metal elements. With the gradual promotion of new energy vehicles, the demand for lithium-ion batteries is also increasing. The amount of waste lithium-ion batteries produced is also increasing rapidly, especially the nickel, cobalt, manganese and other metal elements contained in the cathode materials of lithium-ion batteries will cause great pollution to the environment and will continue to accumulate. The recycling and reuse of metal elements such as nickel, cobalt, and manganese in waste lithium-ion batteries will not only help solve the problem of environmental pollution, but also significantly reduce the production cost of vehicle batteries and bring objective economic benefits. Effective recycling of elements such as nickel, cobalt, manganese and lithium in waste lithium-ion batteries has become the current research direction.

At present, the recovery of metal elements such as nickel, cobalt, and manganese in waste lithium ion batteries mainly adopts wet processing methods, and the separation and extraction of metal elements such as nickel, cobalt, and manganese mainly adopts extraction methods. Patent CN201611136854 provides a method for all extraction of nickel, cobalt and manganese with P507 extractant. Although this method improves the efficiency of nickel, cobalt and manganese extraction, the problem with this solution is that only P507 extractant is used for extraction. The resulting solution still contains a considerable amount of lithium element, and this part of lithium element is difficult to remove, which not only leads to the lower purity of the resulting nickel-cobalt-manganese mixed solution, but also greatly reduces the amount of lithium recovered, and its metal recovery The quality is difficult to meet the requirements. Therefore, it is necessary to propose a new recovery and extraction method to solve the above technical problems.

Summary of the invention

The purpose of the present invention is to provide a method for comprehensively extracting metals from waste lithium-ion batteries, which is used to solve the problem of poor extraction effect in the prior art of wet recovery of elements such as nickel, cobalt, manganese, and lithium.

In order to solve the above technical problems, the present invention provides a comprehensive extraction method for metals from waste lithium-ion batteries. The steps include acid dissolution, alkalization and impurity removal, extraction 1, extraction 2, extraction 3, electrodeposition, purification and purification. Preparation; extraction 1 step specifically includes: using copper extractant DZ973 to extract the alkalized mixture after alkalization and impurity removal, to obtain raffinate 1 and copper sulfate solution.

Among them, the step of acid dissolution specifically includes: immersing the positive and negative electrode mixed powder of the lithium ion battery in an acid solution, and adding a reducing agent until completely dissolved to obtain an acid solution mixture; wherein the acid solution is sulfuric acid or hydrochloric acid, and the reducing agent is H _{A mixture of one or more of 2} O ₂ , SO ₂ , sodium sulfite, and sodium metabisulfite.

Wherein, the added amount of the acid solution is 1 to 2 times the theoretical molar amount in the reaction process; the added amount of the reducing agent is 1 to 3 times the theoretical molar amount in the reaction process.

Among them, the alkalization and impurity removal steps include: adding oxidant and lye to the acid solution mixture, adjusting the pH of the solution to 2.5-5.5, filtering to remove iron and aluminum, and obtaining an alkalizing mixture; the oxidant is air, oxygen, One or more mixtures of sodium chlorate, hydrogen peroxide, sulfur dioxide/air, and the amount of oxidant added is greater than 1.05 times the theoretical molar amount during the reaction; the lye is sodium hydroxide, potassium hydroxide, and ammonia One or more mixtures, and the concentration of the lye is 5 to 32%.

Wherein, the extraction 2 step specifically includes: extracting the raffinate 1 with the P204 extractant to obtain the raffinate 2 and the manganese sulfate solution.

Wherein, the copper sulfate solution obtained in the first step of extraction is recovered at the cathode through the electrodeposition step to obtain copper.

Among them, the three extraction steps specifically include: extracting the raffinate 2 with P204 and Cyanex272 extractants to obtain the raffinate 3 and a battery-grade Ni-Co mixed solution.

Wherein, the manganese sulfate solution obtained in the extraction step 2 is purified and refined to obtain a battery-grade manganese sulfate solution.

Wherein, the raffinate 3 obtained in the three extraction steps is purified and prepared to obtain battery-grade lithium carbonate.

The beneficial effect of the present invention is that, different from the situation in the prior art, the present invention provides a comprehensive extraction method for metals in waste lithium-ion batteries, which can be sequentially recovered to obtain copper, Battery-grade Ni-Co mixture, battery-grade manganese sulfate solution, and battery-grade lithium carbonate realize the comprehensive recovery of multiple metal elements in waste lithium-ion batteries and improve the overall metal recovery rate.

Description of the drawings

FIG. 1 is a process flow diagram of an embodiment of a method for comprehensively extracting metals from a waste lithium ion battery in the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

Please refer to FIG. 1. FIG. 1 is a process flow diagram of an embodiment of a method for comprehensively extracting metals from a waste lithium ion battery in the present invention. The steps of the method for comprehensive extraction of metals in waste lithium ion batteries in the present invention include acid dissolution S1, alkalization and impurity removal S2, extraction 1S3, extraction 2S4, extraction 3S5, electrodeposition S6, purification and purification S7, and purification preparation S8. The steps are explained separately.

S1: Acid soluble. This step specifically includes: immersing the lithium-ion battery positive and negative electrode mixed powder into the combined acid solution and adding a reducing agent until completely dissolved to obtain an acid-soluble mixed solution; wherein the acid solution is sulfuric acid or hydrochloric acid, and the amount of acid solution added is the reaction During the process, the theoretical molar amount is 1 to 2 times. The reducing agent is _{a mixture of one or more of H 2} O ₂ , SO ₂ , sodium sulfite and sodium metabisulfite. The amount of reducing agent added is 1 of the theoretical molar amount in the reaction process. ~3 times, the actual added acid and reducing agent are both excessive than the theoretical value to ensure that the nickel, cobalt, manganese, lithium and other metal elements in the mixed powder of the positive and negative electrodes of the lithium ion battery can be fully dissolved. In this embodiment, the lithium ion battery positive and negative electrode mixed powder is a lithium ion battery system mixture containing nickel, cobalt and manganese, such as a Ni-Co-Mo-Li system containing nickel, cobalt and manganese, a lithium cobalt oxide system, and Ni-Co -A system mixture composed of one or more in the Al system, and these system mixtures can all be used as the above-mentioned lithium ion battery positive and negative electrode mixed powder and applied in the preparation process of the present invention.

S2: Alkalization and impurity removal. This step specifically includes: adding an oxidizer and lye to the acid solution mixture, adjust the pH of the solution to 2.5-5.5, filter to remove iron and aluminum to obtain an alkalized mixture; the oxidizer is air, oxygen, sodium chlorate, and hydrogen peroxide. One or more mixtures of sulfur dioxide/air, and the amount of oxidant added is greater than 1.05 times the theoretical molar amount during the reaction; the lye is one or more of sodium hydroxide, potassium hydroxide, and ammonia The concentration of the lye is 5 to 32%; the purpose of this step is to adjust the acid solution mixture to a suitable alkaline interval, and mainly remove the iron and aluminum elements in the solution in the form of hydroxides.

S3: Extraction 1. This step specifically includes: extracting the alkalized mixture after alkalization and impurity removal with copper extractant DZ973 to obtain raffinate 1 and copper sulfate solution; the purpose of this step is to remove the copper ions in the alkalized mixture It is separated for subsequent electrolytic recovery of copper. In this embodiment, DZ973 is preferably used as the copper extractant. In other embodiments, a similar copper extractant can also be selected according to actual conditions, which is not limited here. In this embodiment, preferably, the organic solvent is DZ973 and sulfonated kerosene in a volume ratio of 1:1 to 1:10, without saponification and recycling, and the extraction ratio is (1 to 4): 1, 3 to 5 countercurrent Extraction, 5~8 stage back extraction, the concentration of reaction acid is 1~5mol/L.

S4: Extraction 2. This step specifically includes: extracting the raffinate 1 with the P204 extractant to obtain the raffinate 2 and the manganese sulfate solution; the purpose of this step is to separate the manganese ions in the extract 1. In this embodiment, the organic solvent is P204 and sulfonated kerosene in a volume ratio of 1:(3～4), the saponification rate is 20%～60%, and the extraction ratio is (1～6): 1,5～15 countercurrent Extraction, 5~15 stages countercurrent washing, washing ratio is (1～6):1, washing acid is 0.1mol/L～2mol/L sulfuric acid, 5～15 stages countercurrent back extraction, back extraction ratio (1～15 ):1, the concentration of acid reflux is 2～6mol/L.

S5: Extract 3. This step specifically includes: extracting raffinate 2 with P204 and Cyanex272 extractant to obtain raffinate 3 and a battery-grade Ni-Co mixture; the purpose of this step is to separate lithium and nickel cobalt in extract 1 . In this embodiment, the organic solvents are P204 and Cyanex272 and sulfonated kerosene in a volume ratio of 1:(3～4), the saponification rate is 40%～100%, and the extraction ratio is (1～6):1,5～15 Stage countercurrent extraction, 5～15 stage countercurrent washing, washing ratio is (1～6):1, washing acid is 0.1mol/L～2mol/L sulfuric acid, 5～15 stage countercurrent extraction, reverse extraction ratio (1 ～15):1, the concentration of reflux acid is 2～6mol/L.

S6: Electrodeposition. This step specifically includes: extracting the copper sulfate solution obtained in step 1, and recovering the cathode copper plate at the cathode through the electrodeposition step.

S7: Purification and refinement. The manganese sulfate solution obtained in the second extraction step is purified and refined to obtain a battery-grade manganese sulfate solution. This step can be carried out by P204 extraction. The purpose is to remove calcium and other impurities in the manganese sulfate solution obtained in the second extraction step. , In order to obtain high-purity battery-grade manganese sulfate solution.

S8: Purification and preparation. The raffinate 3 obtained in the three extraction steps is purified and prepared to obtain battery-grade lithium carbonate, which aims to remove impurities in the raffinate in the three extraction steps to obtain a high-purity battery-grade manganese sulfate solution.

The copper, battery-grade Ni-Co mixture, battery-grade manganese sulfate solution, and battery-grade lithium carbonate that are sequentially recovered through the above steps can be used as raw materials in the production of new lithium-ion batteries, realizing a variety of waste lithium batteries. Reuse of metal elements, and has a high overall metal recovery rate.

The method for comprehensively extracting metals from waste lithium-ion batteries of the present invention will be further detailed below in conjunction with specific embodiments.

Example 1

Weigh 10kg of mixed powder of positive and negative electrodes of lithium ion battery, add 50L pure water to slurry according to the liquid-solid ratio of 5:1, add 12.3L sulfuric acid, 13.5kg 30% hydrogen peroxide for acid leaching, filter to remove insoluble residues to obtain the leachate, cobalt, nickel and manganese The leaching rates are: 99.65%, 99.65%, 98.67%. The pH of the leachate is adjusted to 5.0 with 10% liquid caustic soda while air is blown, and after 2 hours of reaction, it is filtered to remove iron and aluminum to obtain an alkalized mixture. The alkalization mixture is separated by 4-stage countercurrent extraction and separation with 25% copper extractant DZ973 to obtain raffinate 1 and copper sulfate solution; among them, when performing extraction 1 step, the organic solvent is DZ973 and sulfonated kerosene by volume The ratio 1:5 configuration, no need for saponification cycle use, the extraction ratio is 3:1, 3-stage countercurrent extraction, 5-stage back extraction, and the reaction acid concentration is 1mol/L.

The copper sulfate solution obtained can be recovered at the cathode through electrodeposition to obtain copper. The obtained raffinate 1 is subjected to 12-stage countercurrent extraction with P204 with a saponification rate of 30% to obtain raffinate 2 and manganese sulfate solution; wherein, extraction is performed In the second step, the organic solvent is P204 and sulfonated kerosene in a volume ratio of 1:3, the saponification rate is 20%, the extraction ratio is 2:1, the 12-stage countercurrent extraction, the 12-stage countercurrent washing, and the washing ratio is 3:1 , The washing acid is 0.1mol/L sulfuric acid, 8-stage countercurrent back extraction, the back extraction ratio is 6:1, and the reaction acid concentration is 1mol/L.

Purify and refine the obtained manganese sulfate solution to obtain a battery-grade manganese sulfate solution. The obtained raffinate 2 is extracted again with P204 with a saponification rate of 68% to obtain a raffinate 3 and a battery-grade Ni-Co mixture; where When performing the 3 steps of extraction, the organic solvent is P204 and Cyanex272 and the sulfonated kerosene is configured in a volume ratio of 1:3, the extraction ratio is 2:1, 12-stage countercurrent extraction, 12-stage countercurrent washing, and the washing ratio is 3:1 , The washing acid is 0.1mol/L sulfuric acid, 8-stage countercurrent back extraction, the back extraction ratio is 3:1, and the reaction acid concentration is 1mol/L. Thus, a battery-grade nickel-cobalt sulfate mixture can be obtained, and the obtained raffinate 3 can be purified to obtain a battery-grade lithium carbonate product.

Example 2

Weigh 10kg of mixed powder of positive and negative electrodes of lithium ion battery, add 50L pure water to slurry according to the liquid-solid ratio of 5:1, add 12.3L sulfuric acid, 13.5kg 30% hydrogen peroxide for acid leaching, filter to remove insoluble residues to obtain the leachate, cobalt, nickel and manganese The leaching rates are: 99.65%, 99.65%, 98.67%. The pH of the leachate was adjusted to 4.5 with 10% liquid caustic soda while air was blown, and after the reaction was carried out for 2 hours, it was filtered to remove iron and aluminum to obtain an alkalized mixture. The alkalization mixture is separated by 4-stage countercurrent extraction and separation with 25% copper extractant DZ973 to obtain raffinate 1 and copper sulfate solution; among them, when performing extraction 1 step, the organic solvent is DZ973 and sulfonated kerosene by volume The ratio 1:6 configuration, no need for saponification cycle use, the extraction ratio is 3:1, 4-stage countercurrent extraction, 6-stage back extraction, and the reaction acid concentration is 3mol/L.

The copper sulfate solution obtained can be recovered at the cathode through electrodeposition to obtain copper. The obtained raffinate 1 is subjected to 12-stage countercurrent extraction with P204 with a saponification rate of 30% to obtain raffinate 2 and manganese sulfate solution; wherein, extraction is performed In the second step, the organic solvent is P204 and sulfonated kerosene in a volume ratio of 1:3, the saponification rate is 30%, the extraction ratio is 5:1, the 8-stage countercurrent extraction, the 8-stage countercurrent washing, and the washing ratio is 5:1 , The washing acid is 0.5mol/L sulfuric acid, 12-stage countercurrent back extraction, the back extraction ratio is 6:1, and the reaction acid concentration is 3mol/L.

Purify and refine the obtained manganese sulfate solution to obtain a battery-grade manganese sulfate solution. The obtained raffinate 2 is extracted again with P204 with a saponification rate of 68% to obtain a raffinate 3 and a battery-grade Ni-Co mixture; where When performing the 3 steps of extraction, the organic solvent is P204 and Cyanex272 and the sulfonated kerosene is configured in a volume ratio of 1:3, the extraction ratio is 4:1, 12-stage countercurrent extraction, 12-stage countercurrent washing, and the washing ratio is 4:1 , The washing acid is 0.5mol/L sulfuric acid, 8-stage countercurrent back extraction, the back extraction ratio is 5:1, and the reaction acid concentration is 4mol/L. Thus, a battery-grade nickel-cobalt sulfate mixture can be obtained, and the obtained raffinate 3 can be purified to obtain a battery-grade lithium carbonate product.

Example 3

Weigh 10kg of mixed powder of positive and negative electrodes of lithium ion battery, add 50L pure water to slurry according to the liquid-solid ratio of 5:1, add 12.3L sulfuric acid, 13.5kg 30% hydrogen peroxide for acid leaching, filter to remove insoluble residues to obtain the leachate, cobalt, nickel and manganese The leaching rates are: 99.65%, 99.65%, 98.67%. The pH of the leachate was adjusted to 5.5 with 10% liquid caustic soda while air was introduced, and after the reaction for 2 hours, it was filtered to remove iron and aluminum to obtain an alkalized mixed liquid. The alkalization mixture is separated by 4-stage countercurrent extraction and separation with 25% copper extractant DZ973 to obtain raffinate 1 and copper sulfate solution; among them, when performing extraction 1 step, the organic solvent is DZ973 and sulfonated kerosene by volume The ratio of 1:8 configuration, no need for saponification cycle use, the extraction ratio is 4:1, 5-stage countercurrent extraction, 8-stage back extraction, and the acid concentration of 4mol/L.

The copper sulfate solution obtained can be recovered at the cathode through electrodeposition to obtain copper. The obtained raffinate 1 is subjected to 12-stage countercurrent extraction with P204 with a saponification rate of 30% to obtain raffinate 2 and manganese sulfate solution; wherein, extraction is performed In the second step, the organic solvent is P204 and sulfonated kerosene in a volume ratio of 1:4, the saponification rate is 40%, the extraction ratio is 6:1, the 12-stage countercurrent extraction, the 12-stage countercurrent washing, and the washing ratio is 6:1 , The washing acid is 1mol/L sulfuric acid, 8-stage countercurrent stripping, the stripping ratio is 6:1, and the reaction acid concentration is 4mol/L.

Purify and refine the obtained manganese sulfate solution to obtain battery-grade manganese sulfate solution. The obtained raffinate 2 is extracted again with P204 with a saponification rate of 72% to obtain raffinate 3 and battery-grade Ni-Co mixed solution; When performing the 3 steps of extraction, the organic solvent is P204 and Cyanex272 and the sulfonated kerosene is configured in a volume ratio of 1:4, the extraction ratio is 6:1, the 12-stage countercurrent extraction, the 12-stage countercurrent washing, and the washing ratio is 6:1 , The washing acid is 1mol/L sulfuric acid, 8-stage countercurrent back extraction, the back extraction ratio is 8:1, and the reaction acid concentration is 4mol/L. Thus, a battery-grade nickel-cobalt sulfate mixture can be obtained, and the obtained raffinate 3 can be purified to obtain a battery-grade lithium carbonate product.

Different from the state of the art, the present invention provides a comprehensive extraction method for metals in waste lithium-ion batteries. Through three successive extractions followed by refining or purification, copper and battery-grade Ni-Co mixtures can be sequentially recovered. , Battery-grade manganese sulfate solution and battery-grade lithium carbonate, realize the comprehensive recovery of multiple metal elements in waste lithium-ion batteries, and improve the overall metal recovery rate.

It should be noted that the above embodiments belong to the same inventive concept, and the description of each embodiment has its own focus. For the details of the description of individual embodiments, please refer to the descriptions in other embodiments.

The above-mentioned embodiments only express the implementation of the present invention, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the invention patent. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can be made, and these all fall within the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention should be subject to the appended claims.

Claims

A method for comprehensively extracting metals from waste lithium-ion batteries, characterized in that the steps include acid dissolution, alkalization and impurity removal, extraction 1, extraction 2, extraction 3, electrodeposition, purification and purification, and purification preparation;

The extraction step 1 specifically includes: extracting the alkalized mixed liquid after alkalization and impurity removal with the copper extractant DZ973 to obtain raffinate 1 and a copper sulfate solution.
The method for comprehensively extracting metals from waste lithium-ion batteries according to claim 1, wherein the step of acid dissolving specifically includes:

Immerse the mixed powder of the positive and negative electrodes of the lithium ion battery in the acid solution, and add the reducing agent until it is completely dissolved to obtain the acid-soluble mixed solution;

Wherein, the acid solution is sulfuric acid or hydrochloric acid, and the reducing agent is a mixture of one or more of H 2 O 2 , SO 2 , sodium sulfite, and sodium metabisulfite.
The method for comprehensively extracting metals from waste lithium-ion batteries according to claim 2, wherein the added amount of the acid solution is 1 to 2 times the theoretical molar amount during the reaction; the added amount of the reducing agent It is 1 to 3 times the theoretical molar amount in the reaction process.
The method for comprehensively extracting metals from waste lithium-ion batteries according to claim 2, wherein the alkalization and impurity removal step comprises:

Adding an oxidant and a lye to the acid-soluble mixed liquid, adjust the pH of the solution to 2.5-5.5, filter to remove iron and aluminum, and obtain the alkalized mixed liquid;

The oxidant is a mixture of one or more of air, oxygen, sodium chlorate, hydrogen peroxide, and sulfur dioxide/air, and the amount of the oxidant added is greater than 1.05 times the theoretical molar amount during the reaction;

The lye is a mixture of one or more of sodium hydroxide, potassium hydroxide, and ammonia, and the concentration of the lye is 5 to 32%.
The method for comprehensive extraction of metals from waste lithium-ion batteries according to claim 1, wherein the extraction step 2 specifically includes: extracting the raffinate 1 with a P204 extractant to obtain raffinate 2 and Manganese sulfate solution.
The method for comprehensively extracting metals from waste lithium-ion batteries according to claim 1, wherein the copper sulfate solution obtained in the first step of extraction is passed through the electrodeposition step to obtain a cathode copper plate.
The method for comprehensive extraction of metals from waste lithium-ion batteries according to claim 5, wherein the three extraction steps specifically include: using P204 and Cyanex272 extractants to extract the raffinate 2 to obtain the extract Residual liquid 3 and battery-grade Ni-Co mixed liquid.
The method for comprehensively extracting metals from waste lithium ion batteries according to claim 5, wherein the manganese sulfate solution obtained in the second extraction step is subjected to the purification and refining step to obtain a battery-grade manganese sulfate solution.
The method for comprehensively extracting metals from waste lithium-ion batteries according to claim 7, wherein the raffinate 3 obtained in the three extraction steps is subjected to the purification preparation step to obtain battery-grade lithium carbonate.