Investigation into conditions of dissolution of V2O5 and V2O4 when keeping valence

A study has been made of the possibility of dissolving penta- and tetravalent vanadium without alteration of its valence. Dissolution in sulphuric acid solutions results in partial reduction of pentavalent vanadium to the tetravalent state. Hydrofluoric and phosphoric acids being used as solvents does not alter the valence of vanadium. On the basis of the obtained data, a method of dissolving tetra- and pentavalent vanadium without alteration of its valence