Thermodynamic description of the M2O-SiO2 (MÂ =Â K, Na) systems

► The thermodynamic properties and phase relationships of the M2O-SiO2 (M = K, Na) systems were reviewed. ► The liquid phase was described by the ionic two-sublattice model with the formula (M+1)P(O-2,SiO4-4,SiO20,Va-)Q (M = K, Na). ► The thermodynamically calculated phase diagram (based on the CALPHAD method) was carried out.