Features of the formation of the reaction mass and structure of metal powders during the reduction of complex oxide compounds of refractory metals of v and vi groups by vapors of alkaline earth metals

The features of the formation of the reaction mass and the structure of powders of refractory metals of group V (Ta, Nb) and group VI (Cr, W, Mo, MoCr, MoW) formed during the reduction of complex oxide compounds: Mg4Ta2O9, Mg4Nb2O9, MgCr2O4, MgWO4, CaWO4, MgMoO4, CaMoO4, MgW0.3Mo0.7O4, Cr2(MoO4)3, Cr2WO6 with alkaline earth metal vapors (Mg, Ca) was studied. It was determined that after reduction under certain conditions of compounds containing metals of group VI, a spatial separation of products takes place, which consists in the fact that the bulk of the oxide of the reducing metal is located outside the reaction zone . It was shown that powders of both pure metals and alloys have a mesoporous structure. The specific surface area of metal powders is many times greater than the specific surface area of precursor powders