Method and system for preparing high-purity lithium carbonate

Abstract

The invention discloses a method and system for preparing high-purity lithium carbonate. The method for preparing the high-purity lithium carbonate includes the following steps that carbonic acid type salt lake brine is concentrated and then warmed, lithium carbonate is saturated and crystallized out, and crystals are collected to obtain lithium carbonate refined salt; distilled water recovered when brine with the temperature of 60 DEG C or above is evaporated and concentrated is utilized to flush the collected lithium carbonate refined salt, and then sodium sylvite in the refined salt is dissolved; drying is conducted to obtain the high-purity lithium carbonate. According to the process, a chemical reagent is not needed, the lithium carbonate can be purified only through physical operation, the purity of the purified lithium carbonate reaches 95% or above, and therefore transportation cost in later periods and cost of further purification are beneficially reduced. The process is low in requirements for transportation and can not pollute the environment.

Description

technical field [0001] The invention relates to a process and system for purifying lithium carbonate. Background technique [0002] Due to its strong electrochemical activity and being a light metal, lithium has a wide range of uses. At present, the application fields of lithium include: ceramics and glass, synthetic rubber, aluminum production, plastics, pharmaceuticals, lubricants, air conditioners, televisions (fluorescent screens), lithium batteries, lithium alloys and nuclear industry, etc.; consumption reaches tens of thousands of tons per year , and still growing. [0003] In the world's total lithium resources, brine lithium ore accounts for about 75%, and hard rock lithium ore accounts for 25%. In my country's total lithium resources, brine lithium ore accounts for about 72%, and hard rock lithium ore accounts for 28%. Before the 1960s, lithium resources mainly came from hard salt lithium ore. The cost of extracting lithium from salt lakes is 1-1.5 times lower th...

AI Technical Summary

Problems solved by technology

However, after practice, it is found that this technology has the following shortcomings, resulting in losses:

[0006]1. It is necessary to build a large area of ​​salt pan, and the construction cost and later maintenance cost are quite high; at the same time, artificially increased the additional production of the salt lake, destroying the liquid level balance of the salt lake, which may Affect the ecology of the salt lake area;

[0007]2. It is greatly affected by natural conditions;

[0008]3. The prepared lithium salt has low purity and many impurities, and needs to be transported to the factory for further processing; thus, the transportation cost is very high; and most of them are transported impurities "Useless carriage";

[0009]4. It takes a long time to make salt; the process cannot be automated and the efficiency is low

[0010]In addition, the existing salt lakes are basically located in remote areas, with inconvenient transportation, lack of energy and fresh water, which further increases the difficulty of purification

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