Abstract: The invention relates to a process for purifying inorganic materials by treating the materials with a solution of hydrogen fluoride in aqueous hydrofluorosilicic acid. The process involves treating an inorganic material containing at least two species, to at least partially separate a first species contained in the material from a second species contained in the material, and comprises treating the material with a fluorine acid solution comprising aqueous hydrofluorosilicic acid and hydrofluoric acid (HF), such that the first species is converted to a product selected from the group consisting of a fluoride, a fluorosilicate and mixtures thereof, and such that the second species is at least partly unreacted, and separating the second species from the product.

Abstract: The invention relates to a process for purifying inorganic materials by treating the materials with a solution of hydrogen fluoride in aqueous hydrofluorosilicic acid. The process involves treating an inorganic material containing at least two species, to at least partially separate a first species contained in the material from a second species contained in the material, and comprises treating the material with a fluorine acid solution comprising aqueous hydrofluorosilicic acid and hydrofluoric acid (HF), such that the first species is converted to a product selected from the group consisting of a fluoride, a fluorosilicate and mixtures thereof, and such that the second species is at least partly unreacted, and separating the second species from the product.