A Reaction Method for Estimating Gibbs Energy and Enthalpy of Formation of Complex Minerals

Abstract

New and updated thermodynamic data for simple binary compounds are readily available from both experimental measurements and theoretical calculations. Based on these available data, an approach is proposed to predict Gibbs energies and enthalpies of formation for complex minerals of metallurgical, chemical, and other industrial importance. The approach assumes that complex minerals are formed from binary composite oxides, which in turn, are formed from individual pure oxides. The validity of this approach is examined by comparing the calculated values of Gibbs energies and enthalpies against the experimentally measured ones reported in literature. The results show that for typical complex minerals with available experimental data, the calculated results exhibit an average residual of 0.51 pct for Gibbs energies and 0.52 pct for enthalpies, compared to the experimental results. This new approach thus correlates well with experimental approaches and can be applied to most of the complex minerals.