Thermodynamic description of the FeO–Fe2O3–MgO system and its extrapolation to the X–MgO–FeO–Fe2O3 (X = CaO and SiO2) systems.

The content of iron oxides has a large impact on the properties of magnesium refractories, knowledge about the thermodynamic equilibria of the FeO–Fe2O3–MgO system is important for the design of refractory materials and resource utilization of solid wastes. The phase equilibria and thermodynamic data of the FeO–Fe2O3–MgO system have been critically evaluated and re‐optimized using the CALPHAD method. The ionic two‐sublattice model (Fe+2, Mg+2)P(O−2, Va, FeO1.5)Q was used to describe the liquid phase. A set of self‐consistent thermodynamic model parameters is presented to describe the phase equilibrium of the FeO–Fe2O3–MgO system. The calculated phase diagrams and thermodynamic properties, employing the optimized model parameters, exhibit excellent agreement with the experimental data. Moreover, the results demonstrate improved consistency when extrapolated to the multicomponent system, such as CaO–MgO–FeO–Fe2O3 and SiO2–MgO–FeO–Fe2O3 systems. The present thermodynamic modeling is useful to construct multicomponent oxide thermodynamic database and to guide the utilization of solid waste resources. [ABSTRACT FROM AUTHOR]