Method for recycling lithium from waste lithium ion battery positive electrode material leaching waste liquid

Abstract

The invention relates to a method for recovering lithium from a waste lithium ion battery positive electrode material leaching waste liquid. The method comprises the following steps: adjusting the pH value of the waste lithium ion battery positive electrode material leaching waste liquid to be less than 5 by using sulfuric acid, then heating to 60-90 DEG C, and carrying out vacuum concentration to obtain a lithium-containing enriched liquid; adjusting the pH value of the lithium-containing enriched liquid to be more than 10 by adopting sodium hydroxide, performing ultrasonic stirring, standing, and performing solid-liquid separation to obtain a ternary precipitate and a lithium-containing treatment liquid; washing the ternary precipitate with washing water to obtain pure ternary precipitate and a lithium-containing washing solution; the lithium-containing washing liquid and the lithium-containing treatment liquid are combined into lithium-containing fine treatment liquid; under the condition of ultrasonic oscillation, adding a saturated sodium carbonate solution precipitator into the lithium-containing fine treatment liquid for precipitation reaction, keeping the precipitate suspended, and directly filtering to obtain lithium carbonate precipitate and tail liquid; evaporating and crystallizing tail liquid to obtain sodium sulfate and sodium carbonate; washing the lithium carbonate precipitate with water to obtain pure lithium carbonate and washing liquid, drying the pure lithium carbonate to obtain a Li2CO3-0 product, and returning the washing liquid to prepare the saturated sodium carbonate precipitator.

Description

Technical field [0001] The present invention relates to a method of recovering lithium from the waste lithium-ion battery cathode material leaching waste liquid, which belongs to the field of resource utilization of lithium-ion battery waste. Background [0002] In the hydrometallurgical recycling of waste ternary lithium-ion battery cathode material process, due to the process flow and other restrictive factors, it is impossible to fully recover Li and Ni, Co, Mn and other valuable metals in the cathode waste liquid of ternary lithium-ion batteries. Affected by its leaching agent, leaching process and recovery process, valuable metals cannot be fully recovered; When the concentration of Li ions in the leachate drops to 0.072~ 1.604g / L, it is impossible to directly extract Li in the form of lithium carbonate by using sodium carbonate, resulting in a large amount of Li-containing leaching waste liquid. The elemental and chemical composition of the leaching waste liquid is very com...

AI Technical Summary

Problems solved by technology

Although using sulfuric acid, hydrochloric acid, and nitric acid inorganic acids as the leaching system to recover valuable metals such as Ni, Co, Mn, and Li in the positive electrode materials of waste ternary lithium-ion batteries has a high leaching rate; After the recovery of valuable metals, a large amount of Li-containing leaching waste liquid will be produced, which is difficult to re-enter the leaching cycle of the waste positive electrode of lithium-ion batteries. It can only be stored as waste or discharged after reaching the standard. Resource waste and environmental pollution

[0005] Therefore, further processing the leaching waste liquid of lithium-ion battery cathode materials and recovering valuable metals is of great significance to the sustainable utilization of Li resources. Process method of Li element in medium

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