Critical Evaluation and Thermodynamic Optimization of the CaO-P2O5 System

A critical evaluation and thermodynamic optimization of all available experimental data of the CaO-P 2 O 5 system was performed to obtain a set of thermodynamic functions which can reproduce all available and reliable experimental phase diagram and thermodynamic data. The modified quasichemical model, which takes into account short range ordering, was employed to describe the thermodynamic properties of the liquid phase. Discrepancies observed in the Gibbs energy of formation of the compounds were resolved and phase diagram and thermodynamic data of all the solid and liquid phases were well reproduced within experimental errors limits including the sharp liquidus of Ca 3 (PO 4 ) 2 .