Thermodynamic Analysis of Binary and Ternary Silicate Systems by a Structural Model
A critical evaluation of the thermodynamic properties as well as the phase diagrams for the systems MgO-SiO<sub>2</sub> and FeO-SiO<sub>2</sub> is performed with a structural model and for the systems MnO-MgO, FeO-MnO and FeO-MgO through the regular solution model.<br> The structural model for binary silicate melts is now extended to ternary systems. It is shown that, for systems SiO<sub>2</sub>-AO-BO, random mixing of cations A<sup>2+</sup> and B<sup>2+</sup> occurs when the oxides AO and BO behave in a similar way with silicate. If the AO-SiO<sub>2</sub> and BO-SiO<sub>2</sub> binary systems exhibit similar thermodynamic behavior, that is comparable free energies of mixing, the properties of the ternary SiO<sub>2</sub>-AO-BO can be extrapolated from those binary systems in a straightforward fashion. This condition is found in simple silicates such as SiO<sub>2</sub>-MnO-MgO, SiO<sub>2</sub>-FeO-MnO and SiO<sub>2</sub>-FeO-MgO systems where the activities and liquidus temperatures calculated solely from data on the binary sub-systems are in good agreement with measured ternary data.
- ISIJ international
ISIJ international 39(5), 399-408, 1999-05-15
The Iron and Steel Institute of Japan