Continuous acid leaching system and method for controlling reaction temperature by aeration

Abstract

The invention discloses a continuous acid leaching system and method for controlling the reaction temperature through aeration. The method comprises the steps of slurry preparation, primary acid leaching, secondary acid leaching, peracid acid leaching and filter pressing. Slurry is a mixture of nickel cobalt lithium manganate powder, water and acid liquor. Primary acid leaching is carried out in a primary acid leaching reaction kettle, and nickel cobalt manganese lithium is leached by adding sulfuric acid and hydrogen peroxide; and secondary acid leaching is carried out in a secondary acid leaching reaction kettle, and nickel cobalt manganese lithium is leached by adding sulfuric acid and hydrogen peroxide. According to the method, the productivity can be remarkably improved under the condition of ensuring the acid leaching rate, meanwhile, the use amount of sodium carbonate is reduced, the subsequent treatment burden is relieved, and under the condition of the same equipment, the yield of continuous acid leaching is 2.5 times or above that of an intermittent acid leaching method; and the leaching efficiency in the continuous acid leaching process is 90% or above.

Description

technical field [0001] The invention belongs to the field of recovery and utilization of ternary lithium batteries, and in particular relates to a continuous acid leaching system and method that adopts aeration to control reaction temperature. Background technique [0002] With the development of electric vehicles, there will be more and more scrapped ternary lithium batteries. The ternary positive electrode materials separated from these scrap batteries through harmless crushing, as well as the waste materials from the ternary positive electrode materials in the production process, need to undergo acid leaching during the recycling process, and the nickel, cobalt, manganese, lithium metal salt solution is extracted by acid leaching. [0003] Nickel-cobalt-manganese salt is the main raw material for the production of ternary precursors, and the ternary precursor is the main raw material for the production of ternary lithium batteries. The acid leaching of nickel, cobalt, ma...

AI Technical Summary

Problems solved by technology

The rise of liquid temperature leads to the decomposition of hydrogen peroxide, which releases a large amount of heat. This chain reaction may cause the reactor to leak, stagnate production, and even cause safety and environmental accidents.

[0006] At the same time, the acid leaching of traditional ternary cathode materials generally adopts sulfuric acid + hydrogen peroxide acid leaching, and the process usually uses batch reactors. The acid leaching process is accompanied by a large amount of heat release, which is likely to cause temperature rise. The temperature of the acid leaching liquid can reach above 90°C. If the temperature is too high, the hydrogen peroxide will be decomposed and wasted. Secondly, the next feeding can only be carried out after the last acid leaching is completed and the hydraulic pressure of the material in the reactor is empty. Equipment production efficiency is low

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