Thermodynamic Evaluation and Optimization of the Al2O3–SiO2–AlF3–SiF4 Reciprocal System Using the Modified Quasichemical Model

Abstract

All available thermodynamic and phase diagram data for the ternary reciprocal system Al2O3–SiO2–AlF3–SiF4 have been critically reviewed. The oxyfluoride liquid solution was modeled using the Modified Quasichemical Model in the Quadruplet Approximation and the most reliable data have been used to optimize the model parameters. The mullite solid solution was previously modeled using the Compound Energy Formalism. Data for fluor‐topaz have been critically reviewed and a new thermodynamic description has been obtained. Phase equilibrium with the gas phase in the reciprocal system at 1 bar is reproduced.