Method of recovering cobalt from lithium ion battery and cobalt recovering system

Abstract

Method or system comprising the step of not only extracting cobalt from defective positive electrodes with a solvent but also extracting cobalt from extraction residue obtained from defective positive electrodes and magnetized matter obtained from waste lithium ion batteries and runoff batteries (step S100); the step of removing impurities contained in the cobalt extract, thereby obtaining a clean cobalt solution (step S200); the step of forming a cobalt hydroxide cake from the clean cobalt solution (step S300); and the step of electrolyzing an electrolytic solution of cobalt containing the cobalt hydroxide cake as an electrolyte to thereby precipitate metallic cobalt (step S400).

Description

technical field [0001] The invention relates to a method for recovering valuable metals in rechargeable batteries, in particular to a cobalt recovery method and a cobalt recovery system in lithium ion batteries for recovering cobalt contained in waste lithium ion batteries and defective lithium ion batteries. Background technique [0002] Hereinafter, a cobalt recovery method and a cobalt recovery system in a lithium ion battery will be described. [0003] At present, it is well known that a lithium-ion battery is a rechargeable battery with a high electric capacity per unit weight or unit volume. In recent years, such a lithium ion battery has attracted attention as a battery for electronic equipment such as a notebook computer, a mobile phone, and the like that are miniaturized or lightened, and the demand and consumption thereof are rapidly increasing. Therefore, from the viewpoint of effective resource utilization, valuable metals are recovered from used lithium ion bat...

AI Technical Summary

Problems solved by technology

However, in an acidic solvent, in order to make hydrogen peroxide have the function of a reducing agent, it needs to coexist with an acidic agent with strong oxidizing ability such as nitric acid or hot concentrated sulfuric acid, so it is dangerous to operate, and there is a risk of increasing the cobalt recovery operation. question of risk

[0017] Furthermore, hydrogen peroxide is likely to self-decompose depending on the state of the processing solvent and the state of contact with the object to be processed, and the desired reducing agent function may not be exhibited.

For this reason, self-decomposition is suppressed, and it is often difficult to stably obtain a high recovery rate of cobalt.

[0018] And, for the object to be processed, in order to give full play to the reducing effect of hydrogen peroxide, and under the situation of considering the self-decomposition of this hydrogen peroxide, it is necessary to have hydrogen peroxide greater than or equal to 3 times of the theoretical value at least. The risk is further increased, and the operating cost is also increased

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