METHOD FOR OBTAINING CALCIUM FLUORIDE Russian patent published in 2016 - IPC C01F11/22 C02F1/58 C02F101/14 C01D3/02 

FIELD: chemistry.

SUBSTANCE: method for obtaining calcium fluoride includes interaction of calcium compound and fluorine-containing compound. Fluorine-containing compound, namely KF, is obtained from hydrocarbon and water effluent flows after process of obtaining benzines by hydrofluoric acid alkylation by mixing them with potassium hydroxide. Potassium hydroxide solution is taken in stoichiometric excess and circulated through effluent flows. Molar ratio potassium hydroxide:hydrofluoric acid equals (250-400):1. After that, obtained solution is circulated through layer of solid calcium hydroxide, taken in stoichiometric excess. Molar ratio calcium hydroxide: potassium fluoride equals (1.4-2):1. Sediment is dried and calcined. Regeneration of potassium hydroxide, which is returned into the process for hydrogen fluoride extraction, takes place simultaneously with conversion of potassium fluoride into calcium fluoride.

EFFECT: invention makes it possible to obtain pure calcium fluoride from fluorocarbon-containing wastes of process of obtaining benzines by hydrofluoric acid alkylation with complete purification of said wastes from hydrofluoric acid.

1 dwg, 2 tbl