Abstract
In order to estimate molar volume for multicomponent silicate melts, expanded approximation rules was proposed in view of practical use, on the basis of the regular solution approximation rules of exess molar quantities for binary system melts. Necessary parameters for the above rules have been derived using the previous data in binaries and ternaries, etc.. Using these parameters, it was found that the expansivity was related to anion-cation attraction parameter, and the interaction parameter was related to the distance between each network modifier ion arranged in SiO4 tetragonal structure.
From the collation with the data of multicomponent silicate melts, it was confirmed that the above expanded approximation rules were applicable to predict the molar volume of melts over the wide range of composition and temperature discussed.
