Influence of Coarse Aggregate Content on the Thermal Conductivity of Alumina-Spinel Castables

The thermal conductivity of three commercial-quality alumina-spinel castables containing 90–96 wt% A12O3 was measured in the range room temperature to 1000°C by a hot wire method. Experimental results indicate that the thermal conductivity increases with an increase in coarse aggregate content; higher corundum content and purer alumina aggregates are more important than coarse aggregate content for higher thermal conductivity of alumina-spinel castables.