METHOD FOR PRODUCING LITHIUM HYDROXIDE MONOHYDRATE FROM BRINES

The invention relates to LiOHH2O production from lithium-bearing multicomponent hydromineral raw materials. The method includes filtering lithium-bearing brine contaminated with suspended particles with regeneration of filters and processing of used regenerate, and obtaining pregnant lithium-bearing brine, isolation of lithium chloride from the brine in the form of a primary concentrate in sorption-desorption modules, and nanofiltration of the primary lithium concentrate from magnesium, calcium and sulfate ions. By means of reverse osmosis, electrodialysis concentration and ion-exchange purification from impurities followed by thermal concentration, the primary lithium concentrate is converted into a pregnant lithium chloride concentrate which is converted into a LiOH solution by membrane electrolysis. The LiOH solution is boiled down, resulting in LiOH·H2O crystallization. The invention eliminates lithium loss during production, allows for the production of concentrated hydrochloric acid and battery-grade lithium carbonate as by-products, provides an increase in the yield of a commercial-grade product with a decrease in operating costs, decreases the amount of solid production waste and expands the range of lithium-bearing raw materials suitable for LiOH·H2O production.