Viscosity of Heterogeneous Silicate Melts: Assessment of the Measured Data and Modeling

The measured viscosity data of solid-bearing silicate melts from low to high solid fractions in the last 50 years are reviewed. The compiling of these data and the examination of the structural evolution with increasing solid fraction indicate the existence of three rheological regimes: a gradual viscosity increase in the liquid-like regime, an accelerated viscosity increase in the transitional regime and a viscosity plateau in the solid-like regime. An empirical viscosity model based on the modification of the Avrami equation is proposed, enabling viscosity calculation of the solid-bearing silicate melt over the full solid fraction ranges from 0 to 100 vol.%.