Influence of the composition of precursors and reduction conditions on the properties of magnesiothermic molybdenum powders

Resumo

We have investigated the preparation of molybdenum powders by reducing the oxide compounds MoO₃, MgMoO₄, and CaMoO₄ with magnesium vapor at residual argon pressures in the range 5–20 kPa and temperatures in the range 700–800°C. Using the MgMoO₄ and CaMoO₄ compounds as precursors, we have obtained molybdenum powders with specific surface areas of up to 20 m²/g. The powders have a mesoporous structure. The reduction of the molybdenum compounds under such conditions was accompanied by separation of the reaction products due to the removal of magnesium oxide from the reaction zone.