Process for the preparation of niobium oxyfluoride and pyrohydrolysis of niobium oxyfluoride to give niobium oxide

摘要

Process for obtaining niobium from a niobium-containing aqueous hydrofluoric acid solution. The niobium-containing solution is heated with stirring, resulting in evaporation and hydrolysis and formation of a slurry from which niobium oxyfluoride can be separated off and recovered. This can be followed by a process for the conversion of niobium oxyfluoride (NbO2F) into niobium oxide (Nb2O5) in which NbO2F is heated under selected pyrohydrolysis conditions.