An interacting pair model for alkaline binary and ternary liquid silicates: Application to the systems Na2O-K2O-SiO2 and Na2O-Cs2O-SiO2

Among all the available models describing the structure of molten silicates , that of Pelton ef al. allows accurate fitting of the experimental data of the free energies in the binary systems MO-SiO2 with M = Fe, Mn, Pb, and C a. An extension to the ternary systems MO-M'O-SiO2, where M and M' are alka line metals, is proposed. A statistical treatment of the configurations of the solution gives a meaning to the new parameters. The mixed alkaline effe ct is quite well shown by the application of the model to the ternary syste ms K2O-Na2O-SiO2 and Cs2O-Na2O-SiO2, in particular, in the calculation of t he configurational entropy.