Ceramics-Silikáty 38, (3) 151 - 158 (1994)

Giving advantage to the 2.762Al₂O₃ 2SiO₂-formula and applying the phase equilibrium criterion, to the discrete points at the mullite liquidus curve, two sets of ΔG-values of mullite were calculated, by using two mathematical models, for the temperature interval 1860-2122 K as well as the composition range 5-50 mol% Al₂O₃ in the Al₂O₃-SiO₂-system. ΔG-values for 3Al₂O₃ 2SiO₂-formula were presented too. The most probable set of ΔG-values was selected and a correlation between the Gibbs free energy of mullite and temperature was suggested, after adopting both referent state enthalpy and entropy. Also, the parameters in the specific heat function were obtained, as a result of the correlating procedure.