A Pseudo-Multicomponent Approach to Important Ternary Silicate Melts

For the CaO-Al₂O₃-SiO₂, CaO-FeO-SiO₂, and MnO-FeO-SiO₂ ternary silicate melts, there are few models that can accurately predict their component activities. One model that can make a good correlation between the ternary activities and their sub-binary ones is a pseudo-multicomponent approach based on the molecular interaction volume model (MIVM). It does not need any linear or power series composition functions of binary parameters and also does not require any ternary adjustable parameters in addition to its composition equation. The results show that in the CaO-Al₂O₃-SiO₂ system, the predicted values of SiO₂ activity are in good agreement with the experimental data at 1873 K (1600 °C), and those of CaO and Al₂O₃ are in reasonable agreement with the graphical integration of data using the Gibbs–Duhem equation at 1873 K (1600 °C) and experimental data at 1823 K (1550 °C). In the CaO-FeO-SiO₂ and MnO-FeO-SiO₂ systems, the predicted values of FeO and MnO activity are in good agreement with the experimental data, and those of CaO and SiO₂ are in reasonable agreement with the experimental data at 1823 K, 1873 K, and 1803 K (1550 °C, 1600 °C, and 1533 °C).