METHOD OF PRODUCING HIGH-PURITY LITHIUM HYDROXIDE AND HYDROCHLORIC ACID

摘要

FIELD: chemistry.SUBSTANCE: invention can be used in chemical industry to produce crystalline monohydrate of lithium hydroxide which is used in accumulator batteries, and lithium carbonate. The method of producing crystals of monohydrate of lithium hydroxide and hydrochloric acid involves purifying lithium-containing brine via ion exchange in order to reduce concentration of calcium and magnesium ions. The brine undergoes electrolysis to obtain lithium hydroxide solution containing less than 150 ppb of the total amount of calcium and magnesium to obtain gaseous chlorine and hydrogen as by-products. Hydrochloric acid is obtained by burning the obtained chlorine gas with excess hydrogen. Lithium hydroxide solution is concentrated and crystallised to obtain crystals of a monohydrate of lithium hydroxide.EFFECT: invention enables to obtain highly pure aqueous lithium hydroxide solution, from which a crystalline monohydrate of lithium hydroxide can be easily separated, and hydrochloric acid as a by-product.49 cl, 1 dwg, 2 tbl