Method for extracting lithium resource from salt lake brine through electric flocculation

Abstract

The invention discloses a method for extracting a lithium resource from salt lake brine by electric flocculation. The method comprises the following steps: (1) adding the salt lake brine into an electric flocculation device, and carrying out an electric flocculation reaction and solid-liquid separation to obtain a first precipitate and a first tail liquid; (2) calcining the first precipitate to obtain a calcined product; (3) carrying out a leaching reaction on the calcined product, and carrying out solid-liquid separation to obtain a second precipitate and a leachate; (4) adding NaOH into theleachate, performing a reaction, and carrying solid-liquid separation to obtain a magnesium hydroxide product and a lithium-containing solution; and (5) adding sodium carbonate into the lithium-containing solution to react, and carrying out solid-liquid separation to obtain a lithium carbonate product and a second tail liquid. The method realizes efficient extraction of the lithium resource in thesalt lake brine; and an alumina solid product generated in the technological process returns to the electric flocculation process for continuous use, so byproducts generated in the treatment of the salt lake brine with the high magnesium-lithium ratio through a traditional precipitation process are greatly reduced, and pollution to the environment is reduced.

Description

technical field [0001] The invention belongs to the technical field of extracting lithium resources in salt lakes, and in particular relates to a method for extracting lithium resources in salt lake brines by electrocoagulation. Background technique [0002] Lithium exists widely in nature in the form of compounds. Lithium resources that can be developed and utilized at present include granite pegmatite lithium minerals, salt lake brine and seawater. Lithium ore resources mainly occur in salt lake brine and granite pegmatite deposits. Among them, salt lake lithium resources account for 69% of the global lithium reserves and 87% of the global lithium reserve base. The world's important lithium-bearing salt lakes include Bolivia's Uyuni Salt Lake, Chile's Atacama Salt Lake, China's Zabuye Salt Lake and Chaerhan Salt Lake, Silver Peak and Searles in the United States, and Umbremuel in Argentina. Salt Lake and the Dead Sea in the Middle East. Lithium resources in my country'...

AI Technical Summary

Problems solved by technology

The traditional evaporation, crystallization and precipitation method will produce a large number of by-products, which are difficult to handle and easy to cause environmental pollution. Moreover, the evaporation process is very time-consuming and inefficient, and is not suitable for lithium extraction from salt lakes with high magnesium-lithium ratios.

Although the adsorption method can effectively separate lithium and magnesium in a salt lake with a high magnesium-lithium ratio, the adsorption capacity of the adsorbent is low and the regeneration ability is poor.

Solvent extraction method is easy to affect the environment due to the use of a large amount of organic extractant

Although the nanofiltration method is regarded as an environmentally friendly method for extracting lithium from salt lakes, the membrane fouling problem of nanofiltration membranes has not been fully resolved at present, and the cost of this method is relatively high

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