Processing method of wastes produced when battery grade lithium fluoride is manufactured by adopting carbonization method

Abstract

The invention discloses a processing method of wastes produced when battery grade lithium fluoride is manufactured by adopting a carbonization method, and the processing method comprises the steps that: A: excess sodium carbonate is added into a lithium fluoride waste liquor to react with the lithium fluoride waste liquor, a solid lithium carbonate paste is obtained after a reaction product is filtered, and a filter liquor is a spare mixed solution containing the left sodium carbonate; and B: a lithium carbonate waste material and aluminium hydroxide react with excess anhydrous hydrogen fluoride in a fluidized bed to obtain anhydrous aluminum fluoride containing lithium fluoride, and tail gas of the reacted anhydrous hydrogen fluoride is led into the mixed solution containing the left sodium carbonate in the step A so as to obtain a sodium fluoride solution. By adopting the processing method disclosed by the invention, two main wastes produced when the battery grade lithium fluoride is manufactured by adopting the carbonization method are both converted to useful substances capable of being used in downstream industries of inorganic fluorides, so the environmental protection problem to be solved in the fluoride chemical industry and the aluminum electrolysis industry is solved; and in addition, all raw materials are taken from production wastes of the battery grade lithium fluoride, secondary pollution cannot be produced, the resource utilization rates of fluorine and lithium are improved, and sustainable development of the inorganic fluoride chemical industry is urged.

Description

technical field [0001] The invention relates to a method for treating waste produced by carbonization process of battery-grade lithium fluoride. Background technique [0002] Inorganic fluorides mainly include hydrofluoric acid, fluoride salts, fluoride salts and interhalogen compounds. Among them, the varieties of fluoride salts mainly include cryolite, sodium fluoride, lithium fluoride, aluminum fluoride and so on. Cryolite is mainly used in the start-up stage of aluminum electrolysis, and aluminum fluoride is mainly used in the daily operation of aluminum electrolysis, and the amount of both accounts for more than 95% of the fluoride salt products. Lithium fluoride is the main raw material for the production of lithium hexafluorophosphate, a key material for new energy lithium-ion batteries. With the shortage of global oil resources and the continuous deterioration of the climate environment, lithium-ion batteries have broad development prospects as a substitute for non-...

AI Technical Summary

Problems solved by technology

[0004] However, the following wastes can be produced in the process of preparing battery-grade lithium fluoride by carbonization: 1. In order to ensure the purity of lithium bicarbonate, lithium carbonate waste that has not been carbonized will be left after filtering out lithium bicarbonate; 2. In order to ensure the purity of lithium bicarbonate; The quality of lithium fluoride discharges the lithium fluoride waste liquid after filtering out the generated lithium fluoride

The generation of these wastes has increased the environmental protection pressure and production cost of battery-grade lithium fluoride. How to reasonably recover this part of fluorine and lithium resources and reduce environmental protection pressure is the technical bottleneck of battery-grade / high-purity lithium fluoride production.

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