A Thermodynamic Model for Prediction of Iron Oxide Activity in Some FeO‐Containing Slag Systems

A thermodynamic model for calculating the mass action concentrations of structural units in CaO–SiO 2 –MgO–FeO–MnO–Al 2 O 3 –CaF 2 slags, i.e. , the IMCT‐ N i model, has been developed based on the ion and molecule coexistence theory (IMCT). The calculated comprehensive mass action concentration of iron oxides $N_{{\rm Fe}_{t} {\rm O}} $ has been compared with the reported activity of iron oxide $a_{{\rm Fe}_{t} {\rm O}} $ in 14 FeO‐containing slag systems from literatures. The good agreement between the calculated $N_{{\rm Fe}_{t} {\rm O}} $ and reported $a_{{\rm Fe}_{t} {\rm O}} $ indicates that the developed IMCT‐ N i model can be successfully applied to predict the activity of iron oxide $a_{{\rm Fe}_{t} {\rm O}} $ as well as the slag oxidation ability of CaO–FeO (s1), SiO 2 –FeO (s2), CaO–SiO 2 –FeO (s3), CaO–FeO–Al 2 O 3 (s4), SiO 2 –MgO–FeO (s5), SiO 2 –FeO–Al 2 O 3 (s6), CaO–SiO 2 –FeO–Al 2 O 3 (s7), CaO–SiO 2 –MgO–FeO–Al 2 O 3 (s8), SiO 2 –FeO–MnO (s9), SiO 2 –FeO–MnO–Al 2 O 3 (s10), FeO–MnO (s11), FeO–MnO–Al 2 O 3 (s12), CaO–FeO–CaF 2 (s13), and CaO–SiO 2 –FeO–CaF 2 slags (s14) in a temperature range of 1473–1973 K.