A network model for the thermodynamics of multicomponent silicate Melts. I. Binary mixtures MOSiO 2

Abstract

We have developed a network model for the thermodynamics of liquid silicate mixtures. Variation of the interaction parameter with composition is incorporated quite naturally by assuming a functional dependence, not on the silica content, but on the actual degree of polymerization of the silicate network. In this paper, which describes the model for binary mixtures, the interaction parameter is fitted to activity data for binaries of SiO 2 with CaO, FeO, K 2O, MgO, MnO, Na 2O and PbO. For the system MgOSiO 2 we have also fitted the temperature-composition phase diagram.