EFFECT OF Al2O3 ON THE VISCOSITY OF SILICATE MELTS.

Abstract

The results of viscosity measurements for Na//2O-SiO//2-Al//2O//3 and PbO-SiO//2-Al//2O//3 systems and the previous data for CaO-SiO//2-Al//2O//3 and MnO-SiO//2-Al//2O//3 systems were used to evaluate the effect of Al//2O//3 on the viscosity of the ternary aluminosilicate MO-SiO//2-Al//2O//3 system in the range of molar ratio Al//2O//3/MO less than 1. In the Na//2O-SiO//2-Al//2O//3 system, the viscosity greatly increased with the substitution of Al//2O//3 for SiO//2. In the PbO-SiO//2-Al//2O//3 system, the viscosity slightly increased and the rate of increase dropped with decreasing basicity of melts.