THERMODYNAMIC CHARACTERIZATION OF MULLITE

Giving advantage to the 2.762 Al2O3 2SiO(2)-formula and applying the p hase equilibrium criterion, to the discrete points at the mullite liqu idus curve, two sets of Delta G-values of mullite mere calculated, by using two mathematical model, for the temperature interval 1860-2122 K as well as the composition range 5-50 mol% Al2O3 in the Al2O3- SiO2- system. Delta G-values for 3 Al2O3 2SiO(2)- formula were presented too . The most probable set of Delta G-values was selected and a correlati on between the Gibbs free energy of mullite and temperature was sugges ted, after adopting both referent state enthalpy and entropy. Also, th e parameters in the specific heat function were obtained, as a result of the correlating procedure.