阅读说明：本技术 一种钴酸锂电池中有价金属回收的方法 (Method for recovering valuable metal in lithium cobaltate battery ) 是由 张哲鸣 王文伟 于 2020-12-21 设计创作，主要内容包括：一种钴酸锂电池中有价金属回收的方法,通过对废旧的钴酸锂电正极进行处理,得到钴酸锂粉末,在微波条件下进行低温(30℃-50℃)反应,加入酸性溶液以及过氧化氢,并加入草酸对钴进行沉淀,加入碳酸钠对锂进行沉淀,从而实现对钴和锂的回收。该方法反应条件温和,可以在低温下完成对有价金属钴和锂的回收。(A method for recovering valuable metals in a lithium cobaltate battery comprises the steps of processing a waste lithium cobaltate battery positive electrode to obtain lithium cobaltate powder, carrying out low-temperature (30-50 ℃) reaction under the microwave condition, adding an acidic solution and hydrogen peroxide, adding oxalic acid to precipitate cobalt, and adding sodium carbonate to precipitate lithium, so that cobalt and lithium are recovered. The method has mild reaction conditions, and can complete the recovery of valuable metals cobalt and lithium at low temperature.)

1. A method for recovering valuable metals in a lithium cobaltate battery is characterized by comprising the following steps:

(1) discharging the waste lithium cobalt oxide battery, disassembling to obtain a positive plate of the lithium cobalt oxide battery, and calcining to obtain lithium cobalt oxide powder;

(2) dissolving lithium cobaltate powder into the mixed solution according to a preset solid-liquid ratio, and placing the mixed solution into a magnetic stirrer capable of applying microwave radiation and heating functions to perform microwave heating reaction to obtain a reaction solution; the mixed solution comprises at least one of sulfuric acid, citric acid and hydrochloric acid, and also comprises hydrogen peroxide;

(3) adding oxalic acid into the reaction solution for reaction to generate cobalt oxalate precipitate; and after no precipitate is generated, adding sodium carbonate into the precipitate to generate a lithium carbonate precipitate, and drying the cobalt oxalate precipitate and the lithium carbonate precipitate to obtain the cobalt oxalate and the lithium carbonate.

2. The method for recovering valuable metals from lithium cobaltate batteries according to claim 1, wherein in the step (1), the calcination temperature is 400 to 700 ℃ and the calcination time is 0.5 to 3 hours.

3. The method for recovering valuable metals from lithium cobaltate batteries according to claim 1, wherein in the step (2), the predetermined solid-to-liquid ratio is 10 to 100g/L, the molar concentration of the sulfuric acid, the citric acid and the hydrochloric acid is 2.0 to 5.0mol/L, and the volume concentration of the hydrogen peroxide is 20 to 40%.

4. The method for recovering valuable metals from lithium cobaltate batteries according to claim 1, wherein in the step (2), the microwave power in the magnetic stirrer is 400-1000 w.

5. The method for recovering valuable metals from lithium cobaltate batteries according to claim 4, wherein microwave radiation is applied to the whole reaction process in the step (2).

6. The method for recycling valuable metals from lithium cobaltate batteries according to claim 4 or 5, wherein the reaction temperature in the magnetic stirrer is 30-50 ℃ and the stirring speed is 50-300 r/min.

7. The method for recovering valuable metals from lithium cobaltate batteries according to claim 1, wherein in the step (3), the molar concentration of the oxalic acid is 1.0 to 3.0mol/L, the reaction temperature is 30 to 50 ℃, and the reaction time is 1 to 5 hours.

8. The method for recycling valuable metals from lithium cobaltate batteries according to claim 1 or 7, wherein in the step (3), the molar concentration of the sodium carbonate is 1.0-3.0 mol/L, the reaction temperature is 30-50 ℃, and the reaction time is 1-5 hours.

9. The method for recovering valuable metals from lithium cobaltate batteries according to claim 3, wherein the mixed solution comprises citric acid, hydrochloric acid and hydrogen peroxide in a volume ratio of 1:1: 1.

Technical Field

The invention relates to the field of battery material recycling, in particular to a method for recycling valuable metals in a lithium cobaltate battery.

Background

Lithium ion batteries, as electronic consumables, fail to be discarded after a certain period of use. Research shows that positive and negative electrode materials, electrolyte solvent and the like of the lithium ion battery have certain influence on the environment and human health. The waste lithium battery is discarded into the environment, and substances in the battery enter the environment due to rupture of the waste lithium battery for various reasons, so that environmental pollution is caused. The discarding of lithium batteries has the characteristics of high dispersibility and randomness, so that the pollution to the environment is long-term and slow, and the cumulative effect of the pollution is increased along with the increase of the number of the waste lithium ion batteries.

The waste lithium ion battery contains a large amount of cobalt, is heavy metal with rare resources and high price, has high toxicity and is easy to cause environmental pollution. Meanwhile, the cobalt is used as one of indispensable important raw materials in national economic construction and national defense construction, and the dosage demand is increased year by year. However, the mineral reserve of cobalt in China is small, and the cobalt needs to be imported from foreign countries. With the wider application range of lithium batteries, the problems of resource waste and environmental pollution are more and more serious. If the lithium cobaltate in the waste lithium battery can be repaired and recycled, the import of the state to cobalt metal is reduced, and the environmental pressure is relieved. The method has the advantages that the waste lithium ion batteries are subjected to resource treatment, valuable metals rich in the waste lithium ion batteries can be effectively recovered, and the method has economic benefits and remarkable social and environmental benefits. Therefore, the method has great significance for effectively recycling and resource utilization of the waste lithium ion battery.

Currently, research on lithium ion batteries is mainly focused on the positive electrode material LiCoO of lithium batteries₂In addition, because the rare noble metal is contained, the recovery value is higher. In the recycling process, the volume of electronic waste can be reduced, the components of the battery can be effectively separated, rare and precious metals in the battery can be enriched, and the pollution of the waste battery to the environment can be reduced. Currently there are two main recovery methods: physical methods and chemical methods. The physical method is generally used as a pretreatment process, and includes a heat treatment process, a mechanical crushing flotation process and a physical dissolution process, and the chemical method includes an acid leaching process, an alkali leaching process, a solvent extraction process, a biological leaching process, a chemical precipitation process, an electrochemical deposition process and the like. Because the process is single in operation and cannot realize the purpose of effectively separating and recovering all components of the waste battery, the current method for recovering the battery adopts the combination of the methods, and is basically in a laboratory stage, and the large-scale industrialized recovery treatment of the waste lithium ion battery is very little, so that the efficient and environment-friendly method needs to be foundThe treatment process recovers valuable metals such as cobalt, lithium and the like in the waste lithium battery.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provide a method for recovering valuable metals in a lithium cobaltate battery so as to solve the technical problems of low recovery efficiency, high energy consumption and poor environmental friendliness of the valuable metals cobalt and lithium in the lithium cobaltate battery.

The application provides a method for recovering valuable metals in a cobalt acid lithium battery, which comprises the following steps:

(1) discharging the waste lithium cobaltate battery, disassembling the waste lithium cobaltate battery to obtain a positive plate of the lithium cobaltate battery, and calcining the positive plate in a muffle furnace to obtain lithium cobaltate powder;

(2) adding lithium cobaltate powder into the mixed solution according to a preset solid-liquid ratio, and placing the mixed solution into a magnetic stirrer capable of applying microwaves and heating functions to perform microwave low-temperature heating reaction to obtain a reaction solution; the mixed solution comprises at least one of sulfuric acid, citric acid and hydrochloric acid, and also comprises hydrogen peroxide;

(3) adding oxalic acid into the reaction solution for reaction to generate cobalt oxalate precipitate; and after no precipitate is generated, adding sodium carbonate into the precipitate to generate a lithium carbonate precipitate, and drying the cobalt oxalate precipitate and the lithium carbonate precipitate to obtain the cobalt oxalate and the lithium carbonate.

Preferably, in the step (1), the temperature of the muffle furnace is 400-700 ℃, and the calcination time is 0.5-3 hours.

Preferably, in the step (2), the predetermined solid-to-liquid ratio is 10 to 100g/L, the molar concentration of the sulfuric acid, the citric acid and the hydrochloric acid is 2.0 to 5.0mol/L, and the volume concentration of the hydrogen peroxide is 20 to 40%. The solid-to-liquid ratio refers to the ratio of the lithium cobaltate powder to the mixed solution, and in this application, the mixed solution includes some acids such as sulfuric acid, citric acid, hydrochloric acid, and the like, and further includes hydrogen peroxide. Preferably, when the solid-to-liquid ratio is 40-50 g/L, more valuable metals can be precipitated under the condition of adopting less mixed solution, and a better recovery effect can be achieved while waste is avoided.

Preferably, in the step (2), the microwave power in the magnetic stirrer is 400-1000 w, and the microwave radiation is applied in the whole reaction process. Under microwave conditions, the thermal motion of the molecules and the friction between adjacent molecules becomes more severe. The back and forth oscillation and friction of molecules can accelerate the generation of chemical reaction, so that the reaction is more sufficient, and the chemical reaction can be realized at a lower temperature (30-50 ℃) by a mode of heating the inside of the molecules. Compared with the reaction which does not adopt the microwave technology under the same condition, the method can effectively improve the metal leaching rate of cobalt and lithium. Preferably, in the step (2), the reaction temperature in the magnetic stirrer is 30-50 ℃, and the stirring speed is 50-300 r/min.

Preferably, in the step (3), the concentration of the oxalic acid is 1.0-3.0 mol/L, the reaction temperature is 30-50 ℃, and the reaction time is 1-5 hours.

Preferably, in the step (3), the concentration of the sodium carbonate is 1.0-3.0 mol/L, the reaction temperature is 30-50 ℃, and the reaction time is 1-5 hours.

Preferably, the mixed solution comprises citric acid, hydrochloric acid and hydrogen peroxide, and the volume ratio of the citric acid to the hydrochloric acid to the hydrogen peroxide is 1:1: 1. Under the condition of the volume ratio, the mixed solution has better reaction effect.

Detailed Description

Chemical specific examples: the invention will be further illustrated by the following specific examples. It should be understood that the examples are illustrative only and are not to be construed as limiting the scope of the invention. The experimental procedures in the following examples are carried out in the usual manner unless otherwise specified. Materials, reagents, instruments and the like used in the following examples are commercially available unless otherwise specified. Any methods and materials similar or equivalent to those described below can be used in the present invention.

Example 1

(1) Firstly, the waste lithium cobaltate battery is subjected to discharge treatment, and the positive plate of the battery can be obtained after disassembly. Placing the positive plate into a muffle furnace for calcining at the temperature of 450 ℃ for 1.5 hours to obtain black lithium cobaltate powder;

(2) adding lithium cobaltate powder into a three-neck flask filled with mixed liquid of sulfuric acid, citric acid and hydrogen peroxide according to a solid-liquid ratio of 40g/L, wherein the molar concentrations of the citric acid and the sulfuric acid are both 2.0mol/L, the volume concentration of the hydrogen peroxide is 25%, then placing the three-neck flask into a magnetic stirrer with microwave and heating functions for reaction, wherein the reaction temperature is 45 ℃, the microwave power is 700w, the reaction time is 1 hour, and the stirring speed in the magnetic stirrer is 150 r/min;

(3) adding oxalic acid with the concentration of 1.5mol/L into the solution for reaction at the temperature of 45 ℃ for 2 hours to generate cobalt oxalate precipitate;

(4) after no precipitate is generated, adding sodium carbonate with the concentration of 1.0mol/L into the solution, reacting at the temperature of 45 ℃ for 2 hours to generate lithium carbonate precipitate. The finally obtained cobalt oxalate and lithium carbonate can be used as raw materials of other cobalt and lithium products.

The experimental result shows that under the action of microwave, the leaching rate of cobalt and lithium in lithium cobaltate can reach 99.3% and 99.5% by using a mixed system of citric acid, sulfuric acid and hydrogen peroxide, and when oxalic acid and sodium carbonate are respectively added to leach the cobalt and lithium, the reaction rate of the lithium cobaltate reaches more than 98.8%.

Microwave heating and non-microwave heating were compared at 30 ℃ and 50 ℃. See example 1 for additional components and procedures. The experimental results are shown in the following comparative table of leaching rates.

Chart for comparing leaching rate by microwave heating and non-microwave heating

According to the comparative test data, under the same conditions, the microwave heating method can leach more cobalt and lithium at low temperature.

Example 2

(1) Firstly, the waste lithium cobaltate battery is subjected to discharge treatment, and the positive plate of the battery can be obtained after disassembly. Placing the positive plate into a muffle furnace for calcining at 500 ℃ for 2 hours to obtain black lithium cobaltate powder;

(2) adding lithium cobaltate powder into a three-neck flask filled with mixed liquid of sulfuric acid, hydrochloric acid and hydrogen peroxide according to a solid-to-liquid ratio of 60g/L, wherein the concentrations of the hydrochloric acid and the sulfuric acid are 3.0mol/L and the concentration of the hydrogen peroxide is 35%, then placing the three-neck flask into a magnetic stirrer with microwave and heating functions for reaction, wherein the reaction temperature is 30 ℃, the microwave power is 700w, the reaction time is 1.5 hours, and the stirring speed in the magnetic stirrer is 200 r/min;

(3) adding oxalic acid with the concentration of 2mol/L into the solution for reaction at the temperature of 30 ℃ for 3 hours to generate cobalt oxalate precipitate;

(4) after no precipitate is generated, adding sodium carbonate with the concentration of 1.0mol/L into the solution, reacting at the temperature of 30 ℃ for 3 hours to generate lithium carbonate precipitate. The finally obtained cobalt oxalate and lithium carbonate can be used as raw materials of other cobalt and lithium products.

The experimental result shows that under the action of microwave, the leaching rate of cobalt and lithium in lithium cobaltate can reach 99.6% and 99.7% by using a mixed system of hydrochloric acid, sulfuric acid and hydrogen peroxide, and when oxalic acid and sodium carbonate are respectively added to leach the cobalt and lithium, the reaction rate of the lithium cobaltate reaches more than 98.7%.

Example 3

(1) Firstly, the waste lithium cobaltate battery is subjected to discharge treatment, and the positive plate of the battery can be obtained after disassembly. Placing the positive plate into a muffle furnace for calcining at 400 ℃ for 1.5 hours to obtain black lithium cobaltate powder;

(2) adding lithium cobaltate powder into a three-neck flask filled with mixed liquid of citric acid, hydrochloric acid and hydrogen peroxide according to the solid-to-liquid ratio of 100g/L, wherein the concentrations of the citric acid and the hydrochloric acid are both 2.0mol/L, the concentration of the hydrogen peroxide is 35 percent, and the volume ratio of the citric acid to the hydrochloric acid to the hydrogen peroxide is 1:1, then placing the three-neck flask into a magnetic stirrer with microwave and heating functions for reaction, wherein the reaction temperature is 30 ℃, the microwave power is 700w, the reaction time is 1 hour, and the stirring speed in the magnetic stirrer is 150 r/min;

(3) adding oxalic acid with the concentration of 1.5mol/L into the solution for reaction at the temperature of 30 ℃ for 2 hours to generate cobalt oxalate precipitate;

(4) after no precipitate is generated, adding sodium carbonate with the concentration of 1.0mol/L into the solution, reacting at the temperature of 30 ℃ for 2 hours to generate lithium carbonate precipitate. The finally obtained cobalt oxalate and lithium carbonate can be used as raw materials of other cobalt and lithium products.

The experimental result shows that under the action of microwave, the leaching rate of cobalt and lithium in lithium cobaltate can reach 98.3% and 98.1% by using a mixed system of citric acid, sulfuric acid and hydrogen peroxide, and when oxalic acid and sodium carbonate are respectively added to leach the cobalt and lithium, the reaction rate of the lithium cobaltate reaches more than 98.5%.

The present invention has been described in terms of specific examples, which are provided to aid understanding of the invention and are not intended to be limiting. For a person skilled in the art to which the invention pertains, several simple deductions, modifications or substitutions may be made according to the idea of the invention.