Calculation of Viscosity and Thermal Conductivity at a High Temperature for Glasses Based on the SiO2–Al2O3–R2O System (R = Na, K) and Doped with CaO, MgO, and FeO

Viscosity and thermal conductivity are calculated for multicomponent glass-forming oxide mixtures SiO2–MgO–CaO–Al2O3–FeO–K2O–Na2O based on silica. Viscosity polytherms are plotted in the temperature range of 1798–1973 K. Thermal conductivity is calculated at 1823 K. It is shown that the viscosity of oxide solutions is satisfactorily described by a ratio taking into consideration the viscosity of the corresponding SiO2–МеxOy two-component systems. Calculation formulas for viscosity and thermal conductivity are obtained based on the assumption about the presence of only simple cations of metals and oxygen anions in the liquid oxide phase.