Process for the production of calcium fluoride

摘要

A process is disclosed for producing calcium fluoride. The process comprises (a) mixing phosphate rock with aqueous H2SiF6 at ambient temperature for at least one hour; (b) nucleating the calcium fluoride in the slurry prepared in step (a) by reacting the slurry at a temperature and for a time sufficient to initiate and sustain nucleation of calcium fluoride and SiO2 by-product; (c) aggregating the SiO2 by-product by heating the slurry produced in step (b) at a temperature of about 90° C. to about 105° C. for at least 0.5 hours; and (d) recovering a calcium fluoride-containing product of an average particle size of less than 1 micron.