Thermodynamics of the redox reactions between the oxygen and the oxides of the polyvalent elements in glass melts

The redox reactions (RR) in glass melts, containing oxides of different polyvalent elements are analysed. In the following oxides of polyvalent elements are considered and not the corresponding ions as reaction partners of the type: xRed + zO(2) = yOx, where Red and Ox are the oxides. The enthalpies Delta H-T Of these RR are defined using experimental data for various RR on the basis of thermodynamic equations and compared with the appropriate standard enthalpies Delta H-T(o). The ratio x(Ox)/x(Red) is analysed as a function Of the sum (x(Ox) + x(Red)), where x(Ox) and x(Red) are the mole fractions of the oxides Ox and Red. The obtained equation is compared with the experimental data available for the iron oxides.