METHOD OF OBTAINING HIGH-PURITY LITHIUM FLUORIDE Russian patent published in 2008 - IPC C01D15/04 C01D3/02 C01D7/22 

FIELD: chemistry.

SUBSTANCE: method of obtaining high-purity lithium fluoride from processing lithium compounds, such as lithium carbonate or hydroxide, involves transition of the compounds to lithium hydrocarbonate solution by processing of their water solutions by carbon dioxide, sorption purification of the lithium hydrocarbonate solution by cation exchange resin, obtaining of purified lithium carbonate, its washing, preparation of water slurry of purified lithium carbonate, repeated bicarbonisation of water lithium carbonate slurry by carbon dioxide, obtaining of lithium hydrocarbonate solution, followed by fluorination, washing and drying of obtained lithium fluoride. Fluorination is implemented by slow addition and continuous stirring of lithium hydrocarbonate solution in a reactor filled with fluorine hydride with 10-30% stoichiometry excess. Lithium fluoride is washed by distilled water without CO₂ or by 1% solution of fluorine hydride. Lithium fluoride is dried in two stages in vacuum furnace, first stage drying temperature is under 100°C, and second stage drying temperature is under 150°C.

EFFECT: obtaining lithium fluoride with high content of the main substance.

3 ex, 2 tbl, 3 dwg