Dephosphorization during the Process of Vanadium Extraction from Vanadium-bearing Hot Metal Based on the Coexistence Theory of Slag Structure

The activity model of vanadium slag was established according to the coexistence theory of slag structure,based on which the influence of CaO addition on the dephosphorization of liquid iron containing vanadium during the process of producing vanadium slag was conducted in this paper.The equilibrium experiments between the hot metal and the molten slag were designed to validate the proposed model.In the comparison of the calculated value with the measured value,it was found that the calculated value of vanadium and phosphorus distribution ratio (L_V and L_P) between slag and melt agreed well with that of the measured value when the binary basicity was low(R<1).And the relationship D_V=72.43+0.79 D_Pwas obtain through regression analysis.The model calculation results indicated that both L_V and L_P increased with the increase of the binary basicity,and the effect on LPis more obviously.The increase of temperature will reduce L_V,however,it can increase L_P when the binary basicity was low(R<1).With the increase of binary basicity,the activity and activity coefficient ratio of FeO and Mn O increased and that of SiO₂ and TiO₂ decreased.