EXPERIMENTAL INVESTIGATION IN THE VARIATION OF SOAPSTONE AND GRANITE ROCKS AS THERMAL ENERGY STORAGE MATERIALS

To determine the suitability of granite and soapstone rocks as materials for thermal energy storage in solar drying and concentrated solar power generation experimental investigation was conducted. Characterization experiments on thermal chemical, thermophysical and mechanical properties were conducted. Whereby, thermal stability was determined using the thermal gravimetric analyzer (TGA); crystalline phases were studied using the X-ray diffraction (XRD); structural analysis was studied through the petrographic imaging. Moreover, chemical composition was determined using the X-ray fluorescence (XRF) and; high temperature test was done in the high temperature furnace. The thermo-physical properties included density and porosity studied using the displacement method; specific and thermal capacity experimented using the differential scanning calorimetry (DSC) and; thermal diffusivity and conductivities determined through the laser flash apparatus (LFA). The thermo-mechanical properties studied were the Young’s modulus obtained using the nano-indentation method. Sample codes depending on rock type and geotectonic setting of origin - Soapstone from Craton geotectonic setting CS - Soapstone from Usagaran geotectonic setting US - Granite from Craton geotectonic setting CG - Granite from Usagaran geotectonic setting UG