METHOD OF PRODUCING SYNTHETIC FLUORITE Russian patent published in 2012 - IPC C01F11/22 C01B33/10 

FIELD: chemistry.

SUBSTANCE: invention relates to production of synthetic fluorite, having high sorption properties with respect to silicon tetrafluoride. Calcium carbonate powder and 3.5-6.5 M hydrofluorosilicic acid solution are added to a solution heated to 60-80°C, saturated with calcium hexafluorosilicate and containing not less than 3.5 moles of hydrofluorosilicic acid, or to recycled mother solution. The volume of hydrofluorosilicic acid solution fed into the reaction zone is kept equal to the decrease in the recycled mother solution returned to the reaction zone after separating the calcium hexafluorosilicate precipitate. A 6:1 ratio of fluorine to silicon is maintained in the hydrofluorosilicic acid solution by adding hydrogen fluoride when there is fluorine deficit and silicon dioxide or tetrafluoride when there is excess fluorine.

EFFECT: invention enables to obtain high-quality synthetic fluorite which is used as a silicon tetrafluoride sorbent, as well as material in the production of hydrogen fluoride and silicon tetrafluoride, used in electronic, fibre-optic and other engineering fields.

4 cl, 4 tbl