In Situ X-ray Diffraction Studies on the Production Process of Molybdenum

During the production of molybdenum, the first reduction step of molybdenum trioxide to molybdenum dioxide is crucial in directing important product properties like particle size and oxygen content. In this study, the influence of heating rate, hydrogen flow, and potassium content on the reduction of MoO₃ has been investigated via in situ X-ray powder diffraction. For low heating rates, a molybdenum bronze HMoO₃ could be confirmed as an intermediate, while γ-Mo₄O₁₁ can only be observed at high heating rates. Molybdenum formation at temperatures as low as 873 K can be controlled via hydrogen flow. The potassium content of reactants has a direct influence on the amount of Mo₄O₁₁ formed during the reaction as well as rates of Mo₄O₁₁ and MoO₂ formation.