Mechanical Activation of Carboreduction Pathways in MoO3 Powders

We explore the mechanism of carbothermic reduction in MoO3 powders mechanically activated by carbon black.Given the complexity of this system, which involves a mixture of stable and metastable species and complex in situ processes, we combine theoretical and experimental approaches for comprehensive analysis.Ellingham diagrams are used to predict the feasibility of the reaction at different temperatures, whereas the volatility diagrams of the Mo/O/C system are developed to define the conditions under which the solid and gas phases coexist.A mechanically activated mixture of MoO3 and carbon black, ground for 20 hours, was examined by DSC, TG and DTA analyses at several different temperatures.The resulting solid and gaseous products are characterized via the usual techniques.The obtained results prove that all reactions are more complex when stoichiometric calculations are performed.Moreover, by examining the results of experiments carried out under an argon atmosphere at high temperature, we can identify five main stages in the carbothermic reaction of the mixture MoO3-C.