METHOD FOR EXTRACTING LITHIUM FROM LITHIUM-CONTAINING LOW-MAGNESIUM BRINE

摘要

Disclosed is a method for extracting lithium from lithium-containing low-magnesium brine, relating to the technical field of chemistry and chemical engineering. The method comprises the following steps: mixing CaO, water and excess Na₂CO₃ for a reaction, and filtering a resulting reaction liquid to obtain a basic solution and a CaCO₃ solid; adding the basic solution into lithium-containing low-magnesium brine, gradually adjusting the pH of the lithium-containing low-magnesium brine to 11 or more, and precipitating basic magnesium carbonate and a Mg(OH)₂ precipitate to obtain a lithium-containing brine from which magnesium is removed; carrying out extraction on the lithium-containing brine from which magnesium is removed by using a complex organic extraction system, to obtain a loaded organic phase and an extraction raffinate; and mixing the loaded organic phase with an acid aqueous solution, and reverse extracting lithium in the loaded organic phase to obtain a lithium-containing aqueous solution and a lithium-removed organic phase. By means of the method, lithium can be extracted from lithium-containing low-magnesium brine, and the yield of lithium is high, the purity is high, and the cost is low, and same requires a small investment and has a high material cyclic utilization rate.