Microwave heating and fracturing characteristics of basalt insights from infrared thermal imaging

Microwave heating is a promising assisted rock-breakage technology. However, the non-uniform temperature distribution in microwave-heated rocks has not been quantitatively studied. In this work, the microwave heating experiment with power ranging from 1.5-7.5 kW was conducted to investigate the fracturing and heating characteristics of basalt. The results show that the fracture time of basalt decreases non-linearly with increasing power, while the surface temperature increases linearly with irradiation time. For a fixed time, the uniformity of temperature distribution is more affected by power, while for a fixed input energy, the uniformity remains essen?tially unchanged. Increasing microwave power is more effective in enhancing the non-uniformity of temperature distribution and the increase of thermal stress.