Fluorination of germanium concentrates with ammonium fluorides

New method for processing of germanium-containing raw materials to obtain germanium oxide was suggested and studied. The method is based on the fluorination of germanium-containing raw materials with ammonium fluorides, followed by a sublimation isolation of ammonium hexafluorogermanate, its dissolution, and precipitation of germanium oxide from solution. The thermodynamics of the process was calculated and its thermogravimetric analysis was made. The kinetics of germanium oxide fluorination by ammonium hydrodifluoride was experimentally studied. A technological scheme for processing of germanium-containing raw materials with ammonium fluoride was suggested.