Comprehensive recovery method of waste electrolyte containing lithium and aluminum

Abstract

The invention discloses a comprehensive recovery method of waste electrolyte containing lithium and aluminum. The method comprises the following steps: crushing and finely grinding the waste lithium-aluminum-containing electrolyte into electrolyte powder; preparing an acid solution, and adding a leaching enhancer; then adding the electrolyte powder into an acid solution for leaching, and filtering to obtain a filter residue A and a filtrate A; washing and drying the filter residue A to obtain a subcryolite product; adding alkali liquor into the filtrate A for adjustment to generate crystal precipitates, and filtering to obtain filter residues B and filtrate B; drying and calcining the filter residue B to obtain an aluminum fluoride product; adding sulfate into the filtrate B for reaction to generate precipitate, and filtering to obtain filtrate C; evaporating and concentrating the filtrate C to separate out solid substances, filtering to obtain sodium salt and a concentrated solution D, adding carbonate into the concentrated solution D to react, and filtering and drying after reaction to obtain a lithium carbonate product. The storage problem of the waste aluminum electrolyte can be effectively solved, harmlessness and recycling of the waste electrolyte are achieved, and environmental protection is facilitated. Therefore, the method has remarkable economic benefits and social benefits.

Description

1. Technical field: [0001] The invention relates to the technical field of comprehensive extraction and recovery of valuable elements in aluminum electrolytes, in particular to a comprehensive recovery method for waste lithium-containing aluminum electrolytes. 2. Background technology: [0002] In recent years, my country's electrolytic aluminum industry has developed rapidly, and the production capacity and output of electrolytic aluminum have ranked first in the world for many years. However, the grade of bauxite in my country is relatively low, and it is accompanied by a small amount of alkali metal elements such as lithium and potassium. The lithium and potassium elements are not easy to remove during the production of alumina. It is gradually enriched in the aluminum electrolyte, resulting in excessive lithium salt content in the electrolyte of some electrolytic aluminum enterprises in my country (the lithium fluoride content in the electrolyte of most enterprises' elect...

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Problems solved by technology

[0005] Generally speaking, when leaching with inorganic acid and electrolyte pre-roasting are used to modify and enhance leaching, the leaching rate of lithium in the electrolyte is generally low, and it is worth noting that the main product produced by the existing technology is cryolite, normal electrolytic aluminum The demand for cryolite in production is low, and none of the existing technologies can produce aluminum fluoride products with greater demand

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