Preparation of calcium fluoride from fluosilicic acid solutions

摘要

A fluosilicate material is added to a suspension of lime in water heated to a temperature at or near its boiling point to form a solid calcium fluoride product in which the silicon present in the fluosilicate material is in chemical combination with calcium. The amount of calcium in the suspension is in excess of stoichiometric for conversion of CaF2 of all of the fluorine in the fluosilicate and is sufficient to form chemical compounds of calcium and silicon from silicon in the fluosilicate.