METHOD FOR PRODUCING CALCIUM FLUORIDE FROM FLUOROCARBON-CONTAINING WASTE OF ALUMINIUM PRODUCTION Russian patent published in 2017 - IPC C01F11/22 B09B3/00 C01B9/08 C22B3/12 C01D3/02 C25C3/06 

FIELD: chemistry.

SUBSTANCE: method for producing calcium fluoride from fluorocarbon-containing wastes of aluminium production involves treatment of fluor-containing solutions with calcium hydroxide, followed by separation of the solution and a pulp and liberation of calcium fluoride, which is washed with water. As a fluor-containing solution, a solution is used, obtained by leaching solid fine-dispersed fluorocarbon-containing waste of electrolytical aluminium production - sludge from gas cleaning, dust from electrostatic precipitators and spent coal lining. Fluorocarbon-containing wastes are submitted for treatment in a ratio of T:H=:(10-11) with respect to a 2-2.5% solution of sodium hydroxide. The treatment is carried out at a leach solution temperature of 65-85°C.

EFFECT: invention makes it possible to produce calcium fluoride from solid fine-dispersed fluorocarbon-containing waste of electrolytic aluminium production with a fluor content in the solid phase of 12 to 25 percent.

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