Coordinate extracting system for extracting lithium from salt lake brine with extraction method

Abstract

The invention relates to a coordinate extracting system for extracting lithium from salt lake brine with extraction method, which comprises the following steps of (1) acidity of raw material liquid adjustment: adding hydrochloric acid to the salt lake brine to adjust the pH value of the raw material liquid to 1 to 5 so that the raw material liquid is obtained; (2) extracting lithium: carrying out three-stage extraction on the raw material liquid obtained in step (1) by using TBP-BA-FeCl3 solvent naphtha as an extracting agent to obtain an organic phase; (3) organic phase washing: carrying out three-stage washing to the organic phase obtained in the step (2) by using the hydrochloric acid as a washing agent; (4) organic phase reextraction: carrying out three-stage extraction on the organic phase obtained in the step (3) by using hydrochloric acid as a reextraction agent to obtain lithium chloride solution. The invention has the advantages of simple technique, easy control, low reextraction acidity, low requirements on reextraction equipment materials and concentration of lithium in the material brine, and no need of evaporation concentration of thin lithium solution, thereby saving energy, reducing consumption, decreasing the production cost, and simultaneously improving the total recovery rate of the lithium effectively.

Description

technical field [0001] The invention relates to a coordinated extraction system for extracting lithium chloride in the technical field of inorganic chemical industry, in particular to a coordinated extraction system for extracting lithium by a salt lake brine extraction method. Background technique [0002] Lithium is an important rare element, known as "energy metal". Lithium metal and its compounds are widely used in aluminum smelting, lubricating grease, ceramics, glass, air conditioners, high-energy batteries, military industry and other fields. At present, my country's lithium products, especially lithium carbonate, mainly rely on imports. With the gradual depletion of solid lithium resources, lithium extraction from brine has accounted for 80% of all lithium products in the world. The reserves of lithium resources in salt lakes in the Qaidam Basin in my country (calculated as LiCl) are about 15 million tons, which has huge potential economic value. With the commissio...

AI Technical Summary

Problems solved by technology

[0007] During the "Ninth Five-Year Plan" period, Qinghai Institute of Salt Lake, Chinese Academy of Sciences, with the support of national scientific and technological research projects, used TBP-FeCl for the old brine of Chaerhan Salt Lake 3 -Solvent kerosene extraction system has carried out research on lithium extraction technology, the test scale has reached the annual production of LiCl 3t, and successfully completed the intermediate test of lithium chloride extraction from old brine, but due to the high acidity of the extraction system, the requirements for equipment materials are strict, etc. The reason is that industrial application has not yet been realized.

[0008] Lithium extraction by solvent extraction has not been successfully applied to the extraction of lithium in salt lake brine. The material requirements of the equipment are relatively strict

Therefore, the high acidity of stripping has become the bottleneck problem of lithium extraction by liquid phase extraction.