Lithium salt lake brine extraction method

The method of extraction of lithium in the brine a salt lake, comprising the steps of: 1) preparing the organic phase is extracted: the organic phase was extracted and diluents include mixed extractant, wherein the extractant composite tributyl phosphate and N, N- bis (2-ethanesulfonic ethylhexyl) -3-butanone acetamide by volume of 50% is: 50% mixed, sulfonated kerosene diluent; 2) extraction of the aqueous phase: as LiCl-MgCl2-H2O system; 3) extraction of the aqueous phase to adding HCl, FeCl3 · 6H2O, wherein the control amount ratio of iron material, lithium is 1.3: 1, acid concentration of 0.5mol / L, the lithium concentration is 1 ~ 3g / L; 4) in step 3) to give the organic phase was extracted by volume aqueous phase was extracted in step 1) was obtained as a 1: 2 was allowed to stand and phase separate after thorough mixing. The present invention improves the high concentrations of tributyl phosphate extraction apparatus corrosive strong and long-term operation in the extraction agent dissolved in water, not only in loss of serious problems, and to achieve the efficiency of the prior art extraction of lithium. Extraction process is simple and reliable operation.