Thermodynamic activity of FeO in CaO–SiO₂–MnO–FeO–MgO molten slags

Abstract

To understand the thermodynamic characteristics of the melting process for high manganese twinning-induced plasticity steel, the activity coefficient of FeO in molten slag of MnO-CaO-SiO 2 -FeO-MgO slag system with up to 52 mass% MnO was measured at 1450°C by the experiments of the iron equilibrium between liquid silver and molten slag under the mixed gas atmosphere of CO, CO 2 and Ar. The effects of MnO, FeO and the basicity on the activity coefficient of FeO in molten slag were discussed. The relationships between the activity coefficients of FeO, the concentrations of FeO and MnO and the basicity ((mass% CaO + mass% MgO)/mass% SiO 2 ) were investigated by the regression analysis method. The results show that the activity coefficient of FeO was proportional to the reciprocal of FeO concentration, and increased slightly with the increasing MnO, but slowly decreased by increasing the basicity under the research conditions.

Thermodynamic Activity of SiO₂ in CaO–SiO₂–Al₂O₃–MnO–MgO System Molten Slags

“…The experimental device and the experimental process used in this research have been reported in detail in the determination of MnO and FeO activity. 18,19) But in order to measure the temperature of the melt in the crucible more accurately, the thermocouple was moved from the bottom of the crucible into the corundum crucible. The number of reaction crucibles in the corundum crucible was increased to six.…”