METHOD OF PRODUCTION OF LITHIUM FLUORIDES FOR ELECTROLYTIC PRODUCTION OF ALUMINUM (VERSIONS) Russian patent published in 2006 - IPC C01D15/00 C01D15/04 

FIELD: chemical technology and non-ferrous metallurgy; production of lithium-containing fluorides for electrolytic production of aluminum.

SUBSTANCE: proposed method includes selective sorption of lithium from natural salting liquor followed by desorption of it with water, thus obtaining eluate, solution LiCl containing also CaCl₂ and MgCl₂ at ratios dictated by composition of salting liquor. Then eluate is concentrated, treated with water and Li, Mg and Ca carbonates settle, after which they are subjected to treatment with hydrofluoric acid for obtaining mixture of LiF, MgF₂ and CaF₂. Proposed method may be also realized by settling Mg and Ca carbonates from starting liquor by soda solution for obtaining mixture of MgCO₃ and CaCO₃ at low content of Li₂CO₃ and lithium carbonate is added to this mixture in the amount of 30-50% of mass of total content of components; then mixture is stirred and treated with hydrofluoric acid for forming LiF, MgF₂ and CaF₂ fluorides at content of LiF from 30 to 50%. Used as fluorine-containing reagent is hydrofluoric acid, gaseous fluorine and/or gaseous hydrogen fluoride. Use of natural salting liquor makes it possible to obtain fluorides at minimum content of K, Si and Cl admixtures, not exceeding 0.2% of masses.

EFFECT: enhanced efficiency.

4 cl, 2 dwg, 10 ex