Process for the preparation of ultrapure heavy metal fluorides

摘要

This invention provides a method for the preparation of ultrapure active metal fluorides of increased purity from their metal oxides by reacting an active metal with a predetermined amount of HF(aq) to form a solid reaction product which is dried under controlled heating to form a hydrated fluoride. This hydrated active metal fluoride is then subjected to reactive atmosphere processing comprising hydrofluoric acid vapor in a CO2 reactive carrier gas and a selected halide compound in the gas phase for a predetermined period of time to further increase anion purity.