The thermal conductivity of talc as a function of pressure and temperature

Talc is a commonly used pressure-transmitting and gasket material for high-temperature and -pressure applications. The thermal conductivity of talc at high pressures and temperatures is therefore valuable in the design of high-pressure experiments and apparatus. In this paper measurements of the thermal conductivity of fired and unfired talc are presented. Measurements were made at pressures ranging from 0 to 2.5 GPa and temperatures from 150 to 900 K. The thermal conductivity was measured with the hotwire technique. The thermal conductivity results for both the fired and the unfired talc show a slight increase with increasing pressure. The absolute value of the thermal conductivity of talc is lower in the fired material than in the unfired material. In both cases, the thermal conductivity varied less than 15% over the temperature range studied. X-Ray diffraction studies have shown talc to be highly disordered. The results are shown to be consistent with those expected for a disordered crystal.Paper presented at the Tenth Symposium on Thermophysical Properties, June 20–23, 1988, Gaithersburg, Maryland, U.S.A.