Activity model and its application in CaO-FeO-SiO₂-MoO₃ quarternary system

The activity model of CaO-FeO-SiO₂-MoO₃ quarternary system was established according to the coexistence theory of slag structure and the reduction thermodynamics of molybdenum oxide was discussed by applying this model. The activities of SiO₂and MoOs decrease, while that of CaO increases with increasing the basicity of slag. Among SiC, C and Si reactants, the reducing capability of SiC is the strongest, while that of C is the poorest at a high temperature (about 1873 K). It is advantageous to increase the yield of molybdenum by increasing the content of Si or C. Controlling of basicity of slag can prevent the oxidation loss of molybdenum.