A kind of method for preparing high-concentration lithium solution from salt lake brine

Abstract

The invention discloses a method for preparing a high-concentration lithium solution from salt lake brine. Using salt lake brine as a raw material, the salt lake brine is sequentially adsorbed, replaced and decomposed to obtain lithium solution H1 with high lithium and low salt, and then reverse osmosis membrane technology is used to reverse the lithium solution. Osmotic concentration to obtain lithium-containing brine L2 and low-lithium brine W3; then forced evaporation and concentration of lithium-containing brine L2 to obtain high-lithium solution L3; finally, filtrate refining of high-lithium solution L3, and two-stage filtration to obtain calcium and magnesium ions. For the high-concentration lithium salt solution L5 whose amount is less than 1 ppm, the yield of lithium is 67.9%-87.3%. The present invention has wide applicability, simple process, strong process stability, short production cycle, the utilization rate of lithium resources is more than 70% through the optimized combination in the process, and is environmentally friendly. At the same time, the process can be applied to the extraction of brine with low lithium content Lithium is not affected by the ratio of magnesium to lithium, sodium to lithium, and potassium to lithium in brine, and has very good and extensive industrial application prospects.

Description

technical field [0001] The invention belongs to the technical field of lithium extraction from brine, and in particular relates to a method for preparing high-concentration lithium solution from salt lake brine. Background technique [0002] At present, the main processes for separating lithium from salt lake brine include solar pond heating, precipitation, calcination, membrane, adsorption and solvent extraction. From the perspective of practical application, the solar pond heating lithium precipitation method is mainly suitable for carbonate-type brine with high lithium and low magnesium-lithium ratio; the precipitation method is more suitable for brine with medium and low magnesium-lithium ratio; the nanofiltration technology in membrane method, Electrodialysis technology is suitable for brine with low magnesium-lithium ratio; calcining method is more suitable for brine with high magnesium-lithium ratio; the application of the above technology has an equal effect on the i...

AI Technical Summary

Problems solved by technology

From the perspective of practical application, the solar pool heating and lithium sinking method is mainly suitable for carbonate-type brine with high lithium and low magnesium-lithium ratio; the precipitation method is more suitable for brine with medium and low magnesium-lithium ratio; nanofiltration technology in membrane method, Electrodialysis technology is suitable for brine with low magnesium-lithium ratio; calcination method is more suitable for brine with high magnesium-lithium ratio; There are certain restrictions. Lithium-containing raw halogens need to be pretreated by means of concentration and purification. The cycle of the concentration process, the high loss rate of lithium, and the depletion of lithium resources caused by long-term mining will become more and more serious in the future industrial process. The more serious it is, the higher the production cost

In addition, due to environmental pollution caused by organic solvents, harsh extraction process conditions, and high energy consumption, solvent extraction has not been widely used in the production of lithium carbonate from salt lake brine lithium ore.