PNNL

Abstract

A statistical mechanical theory for silica melts is used to investigate the phase equilibrium behavior of binary silicates. The theory couples a Flory-type lattice model with a set of chemical equilibrium reactions that together capture the interplay between the solvation of a metal oxide into the silica network and the rearrangement of the network structure that lead to phase separation. The theory produces two-phase coexistence curves with interesting features characteristic of being in the proximity of a higher-order critical point. The theory contains the qualitative behavior and essential features of simple binary silicate melts.