METHOD OF PRODUCING LITHIUM CHLORIDE FROM LITHIUM-CONTAINING LIQUID Russian patent published in 2024 - IPC C01D15/04 C01D3/04 C01D3/08 C22B26/12 B01D9/02 

FIELD: chemistry.

SUBSTANCE: invention relates to production of lithium chloride during processing of lithium-containing liquid, including from produced water during oil production and process solutions. Method involves reaction of lithium carbonate with a chlorine-containing reagent, wherein lithium carbonate is used in form of an aqueous suspension with weight ratio to water of 1:8–1:10. Lithium carbonate is preliminarily brought to weight ratio to water of 1:8–1:10 by adding distilled water to the lithium-containing liquid with mixing to an aqueous suspension and purification from impurities by recrystallisation while pumping through soluble lithium bicarbonate. Carbonisation process takes place when carbon dioxide is fed into a turbulent flow with pressure which is 1.1–3 times higher than the atmospheric pressure until the concentration of lithium bicarbonate in the liquid phase is 60–63 g/l. Obtained solution is filtered with directing the unreacted precipitate into a lithium-containing liquid, and the purified lithium bicarbonate into a vacuum evaporator for further purification. Purified lithium carbonate is exposed to hydrochloric acid to release carbon dioxide and water and to obtain lithium chloride, obtained solution is additionally neutralized with lithium carbonate, unreacted lithium carbonate is filtered to obtain a solution of lithium chloride in water.

EFFECT: method allows to expand the field of application due to possibility of operation with oil-containing brines and to increase efficiency due to reduction of product losses and elimination of process equipment clogging.

2 cl