^{Relationship of the Thermal Conductivity and Viscosity for CaO-SiO₂-Al₂O₃-R₂O (R=Li, Na, K) Melts}

Abstract

The thermal effusivities of CaO-SiO₂-Al₂O₃-R₂O (R=Li, Na, K) melts were measured by the front-heating front-detection laser flash method. The thermal conductivity was determined from the thermal effusivity, specific heat capacity and density. The specific heat capacity was evaluated based on the additive law, using the liquid state of respective oxides in literature values. The density was measured using Archimedes principle at room temperature in a glassy state. As a result, it was found that the thermal conductivity of CaO-SiO₂-Al₂O₃ melt was lower than those of CaO-SiO₂-Al₂O₃-R₂O (R=Li, Na, K) melts. It was also found that the NBO/T dependence of thermal conductivities for CaO-SiO₂-Al₂O₃-R₂O (R=Li, Na, K) melts was negative. On the other hand, there was no clear relation between the thermal conductivity and the viscosity.