Activity Calculation Model for Oxygen Converter Final Slag

In this paper the activity calculation model for SiO2-Al2O3-CaO-MgO-FeO-MnO slag system has been established according to the molecule-ion coexistence theory. From that the activity of each component in the converter slag at steelmaking temperature can be calculated and then provides the basis for analyzing the equilibrium distribution of element between slag and steel, as well as thermodynamics analysis related to the activity.With the increasing of FeO mass fraction, the activity of 3CaO.SiO2 shows a significant decreasing trend and the activity of MnO.SiO2 and 2MnO.SiO2 increases slowly. The activity of 3CaO.SiO2 increases at first then decreases, with the increasing of basicity. When the basicity w(CaO)/w(SiO2)=3, the activity of 3CaO.SiO2 reaches its maximum value. The activities of MnO.SiO2 and 2MnO.SiO2 decrease gradually.