A method for changing the crystal form of lithium-containing aluminum electrolyte

Abstract

The invention discloses a method for changing the crystal form of a lithium-containing aluminum electrolyte, and relates to the technical field of aluminum electrolyte extraction and recovery. It includes the following steps: S1, pulverizing the aluminum electrolyte containing lithium; S2, mixing the additive with the aluminum electrolyte powder, and mixing uniformly to obtain a mixed material, wherein the additive includes an alkali metal oxide other than lithium, and is baked at a high temperature One or more of the alkali metal oxo acid salts other than lithium that can be converted into alkali metal oxides, the alkali metal fluorides and additives contained in the aluminum electrolyte in the mixed material can be converted into The molar ratio of the sum of alkali metal fluorides to aluminum fluoride is greater than 3; S3, roasting the mixed material at high temperature. The invention can convert the insoluble lithium salt in the aluminum electrolyte into a soluble lithium salt, improves the leaching rate of the lithium salt, improves the purity of the aluminum electrolyte, and reduces the energy consumption of electrolytic aluminum production.

Description

technical field [0001] The invention belongs to the technical field of extraction and recovery of aluminum electrolytes, and relates to a method for changing the crystal form of lithium-containing aluminum electrolytes. Background technique [0002] The rapid development of my country's aluminum industry has led to a large consumption of bauxite resources in my country. High-grade bauxite has been scarce, and a large number of low-grade bauxite has been mined and used. This medium and low-grade bauxite contains a large amount of alkali metal elements, especially the bauxite in the main production areas of bauxite in my country has a high content of lithium salt. A large amount of alumina containing lithium salts is used as raw material for electrolytic aluminum production. This alumina is added to the electrolyte, and these lithium salts will be enriched in the aluminum electrolytic cell during use, resulting in an increase in the content of lithium salts in the aluminum el...

AI Technical Summary

Problems solved by technology

However, since the aluminum electrolyte contains Na 2 LiAlF 6 , NaLi 2 AlF 6 , K 2 LiAlF 6 , KLi 2 AlF 6 and other insoluble lithium salts, these insoluble lithium salts are difficult to dissolve in the acid solution, therefore, the leaching rate of lithium salts is low, and the lithium element in the aluminum electrolyte cannot be fully extracted and recovered, and the purity of the obtained aluminum electrolyte is low, and the production capacity of electrolytic aluminum consumes a lot