阅读说明：本技术 一种利用路易斯酸选择性回收废旧锂离子电池正极材料中锂的方法 (Method for selectively recovering lithium in anode material of waste lithium ion battery by using Lewis acid ) 是由 杨勇霞 关婷 于 2020-12-18 设计创作，主要内容包括：本发明涉及废旧锂离子电池回收技术领域,提供了一种利用路易斯酸选择性回收废旧锂离子电池正极材料中锂的方法。本发明将废旧锂离子电池正极材料与路易斯酸混合进行焙烧处理,利用路易斯酸熔体中过渡金属氧化还原对的电化学氧化还原电位,与废旧锂离子电池材料发生氧化还原反应,锂离子形成可溶性锂盐从锂离子电池正极材料中脱除,再通过浸出和沉淀得到锂盐,实现废旧锂离子电池正极材料中锂的高效选择性提取。本发明流程短,不产生废气和废水,锂选择性高,所得锂盐纯度高。采用本发明的方法对废旧离子电池正极材料中的锂进行提取,锂的浸出率和浸出选择性分别达到95％以上,回收率达到96％以上,锂盐的纯度达到99wt％以上。(The invention relates to the technical field of waste lithium ion battery recovery, and provides a method for selectively recovering lithium in a positive electrode material of a waste lithium ion battery by using Lewis acid. According to the invention, the anode material of the waste lithium ion battery is mixed with Lewis acid for roasting treatment, the electrochemical oxidation-reduction potential of a transition metal oxidation-reduction pair in the Lewis acid melt is utilized to carry out oxidation-reduction reaction with the anode material of the waste lithium ion battery, lithium ions form soluble lithium salt to be removed from the anode material of the lithium ion battery, and the lithium salt is obtained through leaching and precipitation, so that the efficient selective extraction of lithium in the anode material of the waste lithium ion battery is realized. The method has the advantages of short flow, no waste gas and waste water, high lithium selectivity and high purity of the obtained lithium salt. By adopting the method disclosed by the invention to extract lithium in the anode material of the waste ion battery, the leaching rate and the leaching selectivity of the lithium respectively reach more than 95%, the recovery rate reaches more than 96%, and the purity of lithium salt reaches more than 99 wt%.)

1. A method for selectively recovering lithium in a positive electrode material of a waste lithium ion battery by using Lewis acid is characterized by comprising the following steps:

mixing a waste lithium ion battery anode material and Lewis acid, and then roasting to obtain a roasted product;

leaching and solid-liquid separating the roasted product in sequence to obtain a lithium-rich solution and solid slag;

precipitating the lithium-rich solution to obtain lithium salt;

recovering valuable metals from the solid slag.

2. The method according to claim 1, wherein the lewis acid is one or more of transition metal halide, transition metal sulfate and transition metal nitrate; the transition metal halide comprises one or more of transition metal chloride, transition metal bromide and transition metal iodide.

3. The method of claim 2, wherein the transition metal chloride comprises ZnCl₂、CuCl₂、MnCl₂、FeCl₂And NiCl₂One or more of the above; the transition metal bromide comprises CuBr₂、FeBr₂、NiBr₂And ZnBr₂One or more of the above; the transition metal iodide comprises CuI₂、FeI₂、NiI₂And ZnI₂One or more of the above; the transition metal sulfate comprises ZnSO₄、CuSO₄、MnSO₄And NiSO₄One or more of the above; the transition metal nitrate comprises Zn (NO)₃)₂、Cu(NO₃)₂、Mn(NO₃)₂And Ni (NO)₃)₂One or more of them.

4. The method according to claim 1, 2 or 3, characterized in that the molar ratio of the used lithium ion battery positive electrode material to the Lewis acid is (0.01-9): 1.

5. The method according to claim 2, wherein when the Lewis acid is a transition metal halide or a transition metal sulfate, the temperature of the roasting treatment is 200-1200 ℃; when the Lewis acid is transition metal nitrate, the roasting temperature is 40-1200 ℃;

the roasting time is 0.1-8 h, and the roasting atmosphere is one or more of air, oxygen, nitrogen, argon, helium and neon.

6. The method according to claim 1, wherein the pH value of the leaching agent for leaching is 5-9, the temperature of leaching is 25-100 ℃, the time is 10-300 min, and the solid-liquid ratio is 0.1-5000 g-L^-1。

7. The method according to claim 1, wherein the concentration of lithium in the lithium-rich solution is 1-50 g-L^-1。

8. The method according to claim 1, characterized in that the precipitation treatment is: and mixing the lithium-rich solution with a precipitator for precipitation reaction to obtain lithium salt, wherein the purity of the lithium salt is not lower than 99 wt%.

9. The method of claim 8, wherein the precipitant comprises one or more of a carbonate, a phosphate, and carbon dioxide; the temperature of the precipitation reaction is above 25 ℃, and the time is 0.5-6 h.

10. The method of claim 1, wherein the recovering of the valuable metal from the solid slag comprises the steps of: sequentially carrying out acid leaching and precipitation on the solid slag to obtain metal salt;

or, comprising the steps of: and sequentially carrying out acid leaching, extraction and back extraction on the solid slag to obtain metal salt.

Technical Field

The invention relates to the technical field of waste and old ion battery recovery, in particular to a method for selectively recovering lithium in a positive electrode material of a waste and old lithium ion battery by using Lewis acid.

Background

In recent years, the rapid development of the electric automobile industry promotes the rapid increase of the demand of power lithium ion batteries. The service life of the power battery is about 3-8 years, and according to prediction, the accumulated retirement amount of the power lithium ion battery in China in 2020 can reach 36 ten thousand tons, and on one hand, the scrapped battery has obvious environmental risks due to the fact that the scrapped battery contains heavy metals and fluorine-containing organic matters; on the other hand, the alloy contains a large amount of valuable elements such as lithium, cobalt and the like, and has remarkable economic value. Therefore, the technical requirement for efficient resource recovery of the scrapped waste power battery is urgent.

At present, the recovery method of the anode material of the waste lithium ion battery mainly comprises hydrometallurgy and high-temperature pyrogenic process treatment. Hydrometallurgical processes generally use acid and alkali solutions as media to transfer metal elements into a leach solution, separate the metal elements from the leach solution and produce the corresponding product. The process has high purity of recovered products, but has the defects of difficult impurity separation, serious entrainment loss of lithium, consumption of a large amount of acid/alkali and organic liquid, serious corrosion to equipment and easy secondary pollution.

For the high-temperature pyrogenic process recovery treatment, CN107988483A discloses a method for recovering valuable metals from waste lithium ion batteries, in which the waste lithium ion batteries are mixed with carbon powder and then put into a rotary kiln for low-temperature reductive calcination to obtain a calcined product. CN111733326A discloses a method for efficiently recycling ternary anode materials of waste lithium ion batteries. Roasting anode powder and biomass powder of a waste lithium ion battery cathode, performing carbonation leaching on a roasted product, and recovering filtrate to obtain lithium phosphate; leaching filter residues by using sulfuric acid, precipitating to remove metal ions in the leachate to obtain purified leachate, supplementing metal salts into the purified leachate, and then carrying out coprecipitation to obtain the nickel-cobalt-manganese ternary precursor. The lithium salt in the roasted product obtained by the method is lithium carbonate which has poor solubility and is not suitable for large-scale production.

Disclosure of Invention

In view of the above, the present invention provides a method for selectively recovering lithium from a positive electrode material of a waste lithium ion battery by using lewis acid. The method provided by the invention has the advantages of short process, no waste gas and waste water, capability of realizing high-selectivity extraction of lithium and high purity of the obtained lithium salt.

In order to achieve the above object, the present invention provides the following technical solutions:

a method for selectively recovering lithium in a positive electrode material of a waste lithium ion battery by using Lewis acid comprises the following steps:

mixing a waste lithium ion battery anode material and Lewis acid, and then roasting to obtain a roasted product;

leaching and solid-liquid separating the roasted product in sequence to obtain a lithium-rich solution and solid slag;

precipitating the lithium-rich solution to obtain lithium salt;

recovering valuable metals from the solid slag.

Preferably, the lewis acid is one or more of transition metal halide, transition metal sulfate and transition metal nitrate; the transition metal halide comprises one or more of transition metal chloride, transition metal bromide and transition metal iodide.

Preferably, the transition metal chloride comprises ZnCl₂、CuCl₂、MnCl₂、FeCl₂And NiCl₂One or more of the above; the transition metal bromide comprises CuBr₂、FeBr₂、NiBr₂And ZnBr₂One or more of the above; the transition metal iodide comprises CuI₂、FeI₂、NiI₂And ZnI₂One or more of the above; the transition metal sulfate comprises ZnSO₄、CuSO₄、MnSO₄And NiSO₄One ofOne or more of the above-mentioned raw materials; the transition metal nitrate comprises Zn (NO)₃)₂、Cu(NO₃)₂、Mn(NO₃)₂And Ni (NO)₃)₂One or more of them.

Preferably, the molar ratio of the waste lithium ion battery positive electrode material to the Lewis acid is (0.01-9): 1.

Preferably, when the Lewis acid is transition metal halide or transition metal sulfate, the roasting treatment temperature is 200-1200 ℃; when the Lewis acid is transition metal nitrate, the roasting temperature is 40-1200 ℃;

the roasting time is 0.1-8 h, and the roasting atmosphere is one or more of air, oxygen, nitrogen, argon, helium and neon.

Preferably, the pH value of the leaching agent for leaching is 5-9, the leaching temperature is 25-100 ℃, the leaching time is 10-300 min, and the solid-to-liquid ratio is 0.1-5000 g.L^-1。

Preferably, the concentration of lithium in the lithium-rich solution is 1-50 g.L^-1。

Preferably, the precipitation treatment is: and mixing the lithium-rich solution with a precipitator for precipitation reaction to obtain lithium salt, wherein the purity of the lithium salt is not lower than 99 wt%.

Preferably, the precipitant comprises one or more of carbonate, phosphate and carbon dioxide; the temperature of the precipitation reaction is above 25 ℃, and the time is 0.5-6 h.

Preferably, the method for recovering valuable metals from solid slag comprises the following steps: sequentially carrying out acid leaching and precipitation on the solid slag to obtain metal salt;

or, comprising the steps of: and sequentially carrying out acid leaching, extraction and back extraction on the solid slag to obtain metal salt.

The invention provides a method for selectively recovering lithium in a waste lithium ion battery anode material by using Lewis acid. According to the method provided by the invention, the anode material of the waste lithium ion battery is mixed with Lewis acid for roasting treatment, the electrochemical oxidation-reduction potential of a transition metal oxidation-reduction pair in a Lewis acid melt is utilized to carry out oxidation-reduction reaction with the anode material of the waste lithium ion battery, lithium ions form soluble lithium salts (lithium halide, lithium sulfate or lithium nitrate) to be removed from the anode material of the lithium ion battery, and then the lithium salts are recovered through leaching and precipitation treatment, so that the high-efficiency selective extraction of lithium in the anode material of the waste lithium ion battery is realized. Furthermore, the method provided by the invention can be used for recovering the metal elements in the solid slag obtained by leaching treatment, and can be used for simultaneously recovering valuable metals such as Ni, Co, Mn and the like in the anode material of the waste ion battery. Furthermore, a near-neutral leaching agent with the pH value of 5-9 is adopted in the leaching treatment process, and the high-efficiency leaching of lithium can be realized without using strong acid and strong alkali reagents.

The method provided by the invention has the advantages of short flow, no generation of waste gas and waste water, high lithium selectivity and high purity of the obtained lithium salt. The results of the examples show that the extraction of lithium from the anode material of the waste lithium ion battery by the method of the invention respectively achieves the leaching rate and the leaching selectivity of lithium above 95%, the recovery rate is above 96%, and the purity of the obtained lithium salt is above 99 wt%.

Drawings

Fig. 1 is a schematic flow chart of the process for selectively recovering lithium from the anode material of the waste lithium ion battery by using lewis acid in the embodiment of the present invention.

Detailed Description

The invention provides a method for selectively recovering lithium in a waste lithium ion battery anode material by using Lewis acid, which comprises the following steps:

mixing a waste lithium ion battery anode material and Lewis acid, and then roasting to obtain a roasted product;

leaching and solid-liquid separating the roasted product in sequence to obtain a lithium-rich solution and solid slag;

precipitating the lithium-rich solution to obtain lithium salt;

recovering valuable metals from the solid slag.

The method mixes the anode material of the waste lithium ion battery and the Lewis acid and then carries out roasting treatment to obtain a roasted product. The invention has no special requirements on the types of the waste lithium ion battery anode materials, and the waste lithium ion battery anode materials known by the technical personnel in the field can be used for selectively recycling lithium by using the method of the invention. In a specific embodiment of the invention, the waste lithium ion battery positive electrode material is preferably one or more of a waste lithium manganate positive electrode material, a waste lithium cobaltate positive electrode material, a waste lithium nickelate positive electrode material, a waste lithium nickel cobalt aluminate positive electrode material, a waste lithium nickel cobalt manganate positive electrode material and a waste lithium iron phosphate positive electrode material, and specifically may be a mixture of a waste lithium manganate positive electrode material and a waste lithium nickel cobalt manganate positive electrode material, or a mixture of a waste lithium nickelate positive electrode material and a waste lithium cobalt aluminate positive electrode material, or a mixture of a waste lithium nickel cobalt manganate positive electrode material and a waste lithium iron phosphate positive electrode material, or a mixture of a waste lithium manganese lithium manganate positive electrode material, a waste lithium cobalt oxide positive electrode material and a waste lithium nickel cobalt manganate positive electrode material.

In the invention, the Lewis acid is one or more of transition metal halide, transition metal sulfate and transition metal nitrate, and the transition metal halide preferably comprises one or more of transition metal chloride, transition metal bromide and transition metal iodide; the transition metal chloride preferably comprises ZnCl₂、CuCl₂、MnCl₂、FeCl₂And NiCl₂One or more of the above; the transition metal bromide preferably comprises CuBr₂、FeBr₂、NiBr₂And ZnBr₂One or more of the above; the transition metal iodide preferably comprises CuI₂、FeI₂、NiI₂And ZnI₂One or more of the above; the transition metal sulfate comprises ZnSO₄、CuSO₄、MnSO₄And NiSO₄One or more of the above; the transition metal nitrate comprises Zn (NO)₃)₂、Cu(NO₃)₂、Mn(NO₃)₂And Ni (NO)₃)₂One or more of them.

In the invention, the molar ratio of the waste lithium ion battery positive electrode material to the Lewis acid is preferably (0.01-9): 1; in a specific embodiment of the present invention, the molar ratio of the waste lithium ion battery positive electrode material to the lewis acid may be specifically 0.01:1, 0.1:1, 0.2:1, 0.6:1, 1:1, 2:1, 3:1, 1.5:1, or 9: 1. In the specific embodiment of the present invention, preferably, the content of the metal element in the anode material of the waste lithium ion battery is detected, and the molar quantity of the anode material of the waste lithium ion battery is determined according to the detection result.

The invention preferably directly mixes the Lewis acid solid and the anode material of the waste lithium ion battery, and then roasting the mixture.

In the invention, when the lewis acid is a transition metal halide or a transition metal sulfate, the temperature of the roasting treatment is preferably 200 to 1200 ℃, more preferably 500 to 1000 ℃, and specifically may be 400 ℃, 500 ℃, 700 ℃, 900 ℃, 1000 ℃ or 1200 ℃; when the lewis acid is a transition metal nitrate, the temperature of the roasting treatment is preferably 40 to 1200 ℃, more preferably 100 to 1000 ℃, and specifically can be 40 ℃, 50 ℃, 100 ℃, 300 ℃, 400 ℃, 500 ℃, 700 ℃, 900 ℃, 1000 ℃ or 1200 ℃; in the invention, the roasting treatment time is preferably 0.1-8 h, more preferably 1-7 h, and the roasting atmosphere is preferably one or more of air, oxygen, nitrogen, argon, helium and neon; in a specific embodiment of the present invention, the time of the baking treatment may be specifically 0.2h, 0.4h, 1h, 3h, 5h or 8h, and the baking atmosphere may be specifically air, an oxygen-nitrogen mixed atmosphere, an argon-nitrogen mixed atmosphere or an oxygen-argon mixed atmosphere.

In the invention, in the roasting treatment process, the electrochemical oxidation-reduction potential of a transition metal oxidation-reduction pair in the Lewis acid melt is utilized to carry out oxidation-reduction reaction with the waste lithium ion battery material, lithium is formed into lithium halide to be removed from the anode material, and the transition metal salt is converted into oxide. With Lewis acid as ZnCl₂And the lithium ion cathode material is lithium manganate as an example, and the chemical reaction formula of the roasting treatment is as follows:

ZnCl₂+2LiMn₂O₄→2LiCl+4MnO₂+Zn

after the roasting treatment is finished, the obtained roasted product is sequentially leached and subjected to solid-liquid separation to obtain a lithium-rich solution and solid slag. In the invention, the pH value of the leaching agent for leaching is preferably 5-9, more preferably 6-8, and further preferably 7; in a particular embodiment of the invention, the leaching agent is preferably water; lithium in the roasted product exists in the form of lithium halide, the solubility of the lithium in water is high, the transition metal oxide is not easy to dissolve in the water, and the method can realize high-selectivity extraction of the lithium by leaching with a mild neutral leaching agent.

In the invention, the leaching temperature is preferably 25-100 ℃, and more preferably 30-85 ℃; the leaching time is preferably 10-300 min, more preferably 20-250 min, and the solid-to-liquid ratio is preferably 0.1-5000 g.L^-1More preferably 10 to 1000 g.L^-1(ii) a In a specific embodiment of the present invention, the temperature of the leaching may be 25 ℃, 30 ℃, 40 ℃, 50 ℃, 90 ℃ or 100 ℃; the leaching time can be 10min, 20min, 40min, 50min, 100min or 300 min; the liquid-solid ratio of the leaching solution can be specifically 0.1 g.L^-1、10g·L^-1、100g·L^-1、300g·L^-1、1000g·L^-1Or 5000 g.L^-1。

In the present invention, the method of solid-liquid separation is preferably filtration.

In the invention, the lithium-rich solution is specifically a lithium salt (lithium halide, lithium sulfate or lithium nitrate) solution, and the concentration of lithium in the lithium-rich solution is preferably 1-50 g.L^-1Preferably 5 to 45 g.L^-1In an embodiment of the present invention, the concentration of the lithium-rich solution may be 1 g.L^-1、5g·L^-1、10g·L^-1、20g·L^-1、30g·L^-1Or 50 g.L^-1。

In the invention, the main component of the solid slag is transition metal oxide, specifically one or more of manganese oxide, nickel oxide and cobalt oxide, and the component of the solid slag depends on the type of the anode material of the waste lithium ion battery, for example, when the anode material of the waste lithium ion battery is lithium manganate, the main component of the solid slag is manganese oxide, and when the anode material of the waste lithium ion battery is nickel cobalt lithium manganate, the main component of the solid slag is cobalt oxide, nickel oxide and manganese oxide.

After the lithium-rich solution is obtained, the lithium-rich solution is subjected to precipitation treatment to obtain the lithium salt. In the present invention, the precipitation treatment is preferably: mixing the lithium-rich solution with a precipitator for precipitation reaction to obtain lithium salt; the precipitating agent preferably comprises one or more of carbonate, phosphate and carbon dioxide; the carbonate is preferably sodium carbonate, and the phosphate is preferably sodium phosphate; the carbonate and phosphate are preferably used in the form of a saturated solution; the mol ratio of the precipitator to lithium in the lithium-rich solution is preferably 0.8-1.5: 1; when the precipitant is carbonate or carbon dioxide, the obtained lithium salt is lithium carbonate, and when the precipitant is phosphate, the obtained lithium salt is lithium phosphate.

In the present invention, the purity of the lithium salt is not less than 99 wt%, for example, 99.1 wt%, 99.35 wt%, 99.41 wt%, or 99.59 wt%, etc., but is not limited to the recited values, and other recited values within the range of the values are also applicable.

In the invention, the temperature of the precipitation reaction is preferably 25 ℃ or more, more preferably 25 to 90 ℃, and specifically can be 25 ℃, 30 ℃, 35 ℃, 40 ℃, 50 ℃ or 90 ℃; the time of the precipitation reaction is preferably 0.5-6 h, more preferably 0.6-5 h, and specifically may be 0.5h, 0.7h, 1h, 3h, 5h or 6 h.

After the precipitation reaction is completed, the present invention preferably filters the obtained product solution to obtain the lithium salt. The filtrate obtained after filtration is mainly sodium chloride brine which can be used for discharge treatment of waste lithium ion batteries or extraction of industrial sodium chloride crude salt.

After solid slag is obtained, valuable metals are recovered from the solid slag; the recovery method specifically comprises two methods, namely a method I and a method II, which are described as follows:

the first method preferably comprises the following steps: and sequentially carrying out acid leaching and precipitation on the solid slag to obtain metal salt. In the present invention, when the components in the solid slag include only a single kind of transition metal oxide, it is applicable to the method one; the acid used for acid leaching is preferably sulfuric acid; the invention has no special requirements on the specific conditions of acid leaching, and the conditions well known by the technicians in the field can be adopted; the invention has no special requirements on the specific conditions of the precipitation, and the precipitation can be carried out by using a precipitator which is well known to those skilled in the art according to the types of transition metal elements in the pickle liquor.

The second method comprises the following steps: and sequentially carrying out acid leaching, extraction and back extraction on the solid slag to obtain metal salt. In the invention, when the components in the solid slag include more than 2 transition metal oxides, the method is suitable for the second method; the acid used for acid leaching is preferably sulfuric acid; the invention has no special requirements on the specific conditions of acid leaching, and the conditions well known by the technicians in the field can be adopted; the present invention does not require specific conditions for the extraction and stripping, and the extraction and stripping can be performed according to the kind of transition metal by a method known to those skilled in the art.

The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention.

Fig. 1 is a schematic diagram of a process for selectively recovering lithium from a waste lithium ion battery positive electrode material by using lewis acid in an embodiment of the present invention, in which the waste lithium ion battery positive electrode material and lewis acid are mixed, and then subjected to a roasting treatment, a near-neutral leaching agent is used to leach a roasted product, so as to obtain a lithium-rich solution and solid slag, a lithium salt is recovered from the lithium-rich solution, and a nickel-cobalt-manganese metal salt is recovered from the solid slag.

In the following examples, leaching rate (X)_i) And leaching selectivity (XS)_i) Calculated according to formula I-II:

in formulae I to II, C_iThe concentration of i in the leachate, g.L (when calculating the leaching rate of lithium, C)_iI.e. the concentration of Li in the leachate); v is the volume of the leachate, L; m is_iIs the mass of i contained in the initial material, g; m_iIs the atomic weight of i.

Example 1

The positive pole waste material that this embodiment adopted is nickel cobalt lithium manganate, and the quality percentage content of metal in the test positive pole waste material is: co: 11.96%, Li: 6.26%, Al: 0.3%, Ni: 29.62%, Mn: 17.32 percent. The recovery steps are as follows:

(1) mixing the anode scrap with CuCl₂、CuI₂Uniformly mixing the raw materials according to a molar ratio of 1:2:1, and roasting the mixture in an air atmosphere at 600 ℃ for 3 hours to obtain a roasted product.

(2) Using water as a leaching agent, and leaching the roasted product obtained in the step (1) with the solid-liquid ratio of 500 g.L^-1The leaching temperature is 45 ℃, and the leaching time is 60 min. Filtering and separating to obtain lithium-rich solution and solid slag.

(3) And (3) introducing a saturated sodium carbonate solution into the lithium-rich solution obtained in the step (2) to obtain lithium carbonate, and preparing cobalt salt, nickel salt and manganese salt from the solid slag through sulfuric acid leaching, extraction and back extraction in sequence.

In this example, the lithium concentration in the lithium-rich solution was 20.6 g.L^-1The leaching rate of lithium is 98.24%, the selectivity of lithium is 96.32%, the recovery rate is 96.31%, and the purity of the obtained lithium carbonate is 99.51%;

example 2

The positive electrode waste material adopted in the embodiment is lithium cobaltate, and the mass percentage of the metal in the positive electrode waste material is tested as follows: co: 45.28%, Li: 6.13%, Al: 0.2%, Ni: 0.04%, Mn: 0.06 percent. The recovery steps are as follows:

(1) mixing the anode scrap with CuCl₂Uniformly mixing the raw materials according to a molar ratio of 1:3, and roasting the mixture in a nitrogen atmosphere at a roasting temperature of 500 ℃ for 5 hours to obtain a roasted product.

(2) Using water as a leaching agent, and leaching the roasted product obtained in the step (1) with a solid-to-liquid ratio of 300 g.L^-1The leaching temperature is 25 ℃, and the leaching time is 30 min. Filtering and separating to obtain lithium-rich solution and solid slag.

(3) Introducing CO into the lithium-rich solution obtained in the step (2)₂Preparing lithium carbonate, and preparing cobalt salt from the solid slag through sulfuric acid leaching and precipitation.

In this example, the lithium concentration in the lithium-rich solution was 17.98 g.L^-1The leaching rate of lithium was 99.81%, the selectivity of lithium was 95.12%, the recovery rate was 97.1%, and the purity of the obtained lithium carbonate was 99.58%.

Example 3

The anodal waste material that this embodiment adopted is the mixture of nickel cobalt lithium manganate and lithium manganate, and the mass percent content of metal in the measurement anodal waste material is: co: 8.56%, Li: 7.01%, Al: 0.6%, Ni: 25.42%, Mn: 30.74 percent. The recovery steps are as follows:

(1) mixing the anode scrap with MnCl₂Uniformly mixing the raw materials according to a molar ratio of 1:5, and roasting the mixture in an air atmosphere at 400 ℃ for 5 hours to obtain a roasted product.

(2) Using water as a leaching agent, and leaching the roasted product obtained in the step (1) with the solid-liquid ratio of 500 g.L^-1The leaching temperature is 35 ℃, and the leaching time is 60 min. Filtering and separating to obtain lithium-rich solution and solid slag.

(3) And (3) introducing a saturated sodium carbonate solution into the lithium-rich liquid obtained in the step (2) to prepare lithium carbonate, and preparing cobalt salt, nickel salt and manganese salt from the solid filter residue through sulfuric acid leaching, extraction and back extraction in sequence.

In this example, the lithium concentration in the lithium-rich solution was 30.45 g.L^-1The leaching rate of lithium is as high as 99.12%, the selectivity of lithium is 97.46%, the recovery rate is 97.24%, and the purity of the obtained lithium carbonate is 99.61%.

Example 4

The positive electrode scrap used in this example was identical to that used in example 1:

(1) mixing the anode waste with ZnSO₄Uniformly mixing the raw materials according to a molar ratio of 0.1:1, and roasting the mixture in a nitrogen atmosphere at a roasting temperature of 500 ℃ for 6 hours to obtain a roasted product.

(2) Using water as a leaching agent, and leaching the roasted product obtained in the step (1) with the solid-liquid ratio of 400 g.L^-1The leaching temperature is 25 ℃, and the leaching time is 30 min. Filtering and separating to obtain lithium-rich solution and solid slag.

(3) Introducing CO into the lithium-rich solution obtained in the step (2)₂Preparing lithium carbonate, and preparing cobalt salt from the solid slag through sulfuric acid leaching and precipitation.

In this example, the lithium concentration in the lithium-rich solution was 29.43 g.L^-1The leaching rate of lithium was 97.35%, the selectivity of lithium was 96.12%, the recovery rate was 97.11%, and the purity of the obtained lithium carbonate was 99.56%.

Example 5

The positive electrode scrap used in this example was identical to that used in example 1:

(1) mixing the anode scrap with MnSO₄The molar ratio of the raw materials is 0.2:1, uniformly mixing, and roasting in a nitrogen atmosphere at the roasting temperature of 550 ℃ for 5 hours to obtain a roasted product.

(2) Using water as a leaching agent, and leaching the roasted product obtained in the step (1) with the solid-liquid ratio of 350 g.L^-1The leaching temperature is 25 ℃, and the leaching time is 30 min. Filtering and separating to obtain lithium-rich solution and solid slag.

(3) Introducing CO into the lithium-rich solution obtained in the step (2)₂Preparing lithium carbonate, sequentially leaching solid residues and filter residues by sulfuric acid and precipitating to prepare cobalt salt.

In this example, the lithium concentration in the lithium-rich liquid was 35.1 g.L^-1The leaching rate of lithium was 96.71%, the selectivity of lithium was 95.88%, the recovery rate was 96.14%, and the purity of the obtained lithium carbonate was 99.31%.

Example 6

The positive electrode scrap used in this example was identical to that used in example 1:

(1) mixing the anode scrap with Zn (NO)₃)₂Uniformly mixing the raw materials according to a molar ratio of 0.4:1, and roasting the mixture in a nitrogen atmosphere at a roasting temperature of 110 ℃ for 6 hours to obtain a roasted product.

(2) Using water as a leaching agent, and leaching the roasted product obtained in the step (1) with a solid-to-liquid ratio of 300 g.L^-1The leaching temperature is 25 ℃, and the leaching time is 30 min. Filtering and separating to obtain lithium-rich solution and solid slag.

(3) Introducing CO into the lithium-rich solution obtained in the step (2)₂Preparing lithium carbonate, and preparing cobalt salt from the solid slag through sulfuric acid leaching and precipitation.

In this example, the lithium concentration in the lithium-rich solution was 29.18 g.L^-1The leaching rate of lithium was 95.82%, the selectivity of lithium was 96.13%, the recovery rate was 97.12%, and the purity of the obtained lithium carbonate was 99.32%.

Example 7

The positive electrode scrap used in this example was identical to that used in example 1:

(1) mixing the anode scrap with Ni (NO)₃)₂Uniformly mixing the raw materials according to a molar ratio of 0.2:1, and roasting the mixture in a nitrogen atmosphere at the roasting temperature of 150 ℃ for 7 hours to obtain a roasted product.

(2) Using water as a leaching agent, and leaching the roasted product obtained in the step (1) with the solid-liquid ratio of 320 g.L^-1The leaching temperature is 25 ℃, and the leaching time is 30 min. Filtering and separating to obtain lithium-rich solution and solid slag.

(3) Introducing CO into the lithium-rich solution obtained in the step (2)₂Preparing lithium carbonate, and preparing cobalt salt from the solid slag through sulfuric acid leaching and precipitation.

In this example, the lithium concentration in the lithium-rich solution was 28.91 g.L^-1The leaching rate of lithium was 96.91%, the selectivity of lithium was 95.85%, the recovery rate was 96.78%, and the purity of the obtained lithium carbonate was 99.24%.

Comparative example 1

The composition of the positive electrode scrap was the same as in example 1; the recovery procedure is the same as in example 1, except that: in step (1) does not addCuCl₂And CuI₂。

The lithium concentration in the obtained lithium-rich liquid is 0.6 g.L^-1The lithium carbonate is not prepared in the step (4), the leaching rate of lithium is 0.65 percent, and the recovery rate is 0.57 percent; in the comparative example, no Lewis acid solid is added, the lithium ion battery anode waste material does not react in the roasting treatment process, and lithium ions cannot enter a liquid phase in the leaching process, so that the leaching rate is very low.

According to the embodiment, the electrochemical oxidation-reduction potential of the transition metal oxidation-reduction pair in the Lewis acid melt is utilized to carry out oxidation-reduction reaction with the waste lithium ion battery material, so that lithium ions can be effectively removed from the lithium ion battery anode material, and the efficient selective recovery of the lithium ions can be realized through leaching treatment; the method provided by the invention has the advantages of short flow, no waste gas and waste water generation, cost saving and easy realization of industrial application.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.