METHOD FOR PRODUCTION OF CALCIUM FLUORIDE Russian patent published in 1997 - IPC

FIELD: chemical industry. SUBSTANCE: method involves hydrolysis of silicium hydrogen fluoride acid by ammonium-containing reagent and filtration thus obtained pulp of silicium dioxide to prepare solution of ammonium fluoride. The process is followed by interaction of said solution with calcium carbonate and by separation of calcium fluoride. Mentioned above hydrolysis takes place at 35-50 C; before filtration said pulp of silicium dioxide is concentrated. Said solution of ammonium fluoride is divided in two streams at their ratio 1:(0.5-5) respectively, the former is fed for production of mentioned above ammonium-containing reagent, the latter is fed for interaction with calcium carbonate. EFFECT: improves efficiency of the method. 12 cl