Contribution of thermal radiation in measurements of thermal conductivity of sandstone

The effective thermal conductivity of sandstone at high pressures of up to 400 MPa and temperatures of 273–523 K has been studied. It has been shown that the degree of crystallization of rock-forming minerals substantially influences the temperature and pressure dependences of the thermal conductivity. The contribution of the radiation heat transfer in measurements of the thermal conductivity of sandstone at various temperatures has been analyzed taking into account the reflection and attenuation of the thermal radiation. The results of measuring the reflection and absorption spectra of the thermal radiation have been presented.