Measurement of thermal expansion coefficient of rock minerals using XRD and its implications to thermal damage mechanism

The measurement of thermal expansion coefficient (TEC) of rocks is of vital importance to various geotechnical engineering applications, such as high-level radioactive waste disposal, enhanced geothermal energy exploitation, ultra-deep borehole stability, liquid nitrogen storage, etc. However, previous researchers mainly focused on the thermal expansion coefficient of various rocks, instead of the constituent minerals. In this manuscript, we measured the both temperature-dependent volume and linear thermal expansion coefficients of two rock-forming minerals (quartz and albite) using both high-temperature X-ray diffraction (XRD) as well as low-temperature XRD. It is found that there exist strong anisotropic linear thermal expansion coefficients of the two minerals, which can provide strong reference for the relevant engineering applications and numerical simulations.