PROCESS FOR THE PREPARATION OF ULTRAPURE HEAVY METAL FLUORIDES

摘要

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.