Process for extracting lithium from salt lake water subjected to calcium and magnesium preseparation

Abstract

The invention relates to a process for extracting lithium from salt lake water subjected to calcium and magnesium preseparation. A low-carbon chain organic compound, such as ethanol, propanol or acetone as a solvent for extracting lithium is fully mixed with solid mixed salts obtained after salt lake water is subjected to calcium and magnesium removal or a saturated solution of the solid mixed salts so that LiCl enters an organic solvent, other salts are retained in a solid phase, and the aims of separating, extracting and purifying lithium are achieved. According to the obtained lithium-contained organic solution, lithium carbonate is precipitated by ammonium carbonate, and desalinization is carried out by a continuous ion exchange system consisting of hydrogenous and oxyhydrogen resin, or lithium chloride is directly removed from the lithium-chloride-containing organic solution by the continuous ion exchange system consisting of hydrogenous and oxyhydrogen resin. The organic solvent obtained after desalination treatment only contains water without salt, and the process is used for water separation recycling and organic solvent return process by adopting a pervaporation method.

Description

technical field [0001] The invention relates to a process for extracting lithium from lithium-containing salt lake water, in particular to a new method for further separating, extracting and purifying lithium chloride from the lithium-containing salt lake water after pre-separating calcium and magnesium. Background technique [0002] Lithium-containing saline lake water is currently the main resource for lithium extraction at home and abroad. my country's saline lake water resources are rich and diverse, mainly distributed in four provinces, Qinghai, Tibet, Xinjiang, and Inner Mongolia. Among them, the Qaidam Basin Salt Lake in Qinghai and the Zabuye Salt Lake in Tibet are the most famous. Their composition and reserves are shown in the table below. [0003] Reserves of lithium salts in major salt lakes in my country (calculated as LiCl, 10,000 t) and composition / wt% [0004] [0005] Although my country has certain advantages in terms of reserves, the quality of salt la...

AI Technical Summary

Problems solved by technology

Using the method of reflux extraction, the obtained lithium-containing acetone solution is evaporated to drive away the acetone to obtain solid LiCl [2] , obviously this method consumes a lot of energy, and there is no method for how to recover acetone, so further tests cannot be carried out, and industrial application cannot be carried out.

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