Abstract:
Microwave radiation technology,owing to its advantages of selective heating,instantaneous response,and volumetric heating,has shown broad application prospects in mineral processing and geotechnical engineering. This study systematically investigated the thermodynamic responses and damage evolution characteristics of 11 common rock-forming minerals and 8 types of rocks with different mineral compositions under microwave irradiation. Microwave irradiation experiments were conducted at powers of 0. 5 k W and 1. 0 k W for a duration of 3 minutes,combined with high-resolution CT scanning and three-dimensional reconstruction techniques,to analyze the temperature rise behavior and internal damage evolution of minerals and rocks.The results indicate that,based on their microwave heating effects,minerals can be classified into three sensitivity types-high,medium,and low-among which hematite exhibits the strongest microwave absorption capacity. The temperature rise behavior of rocks is significantly controlled by their mineral composition;a higher content of highly sensitive minerals leads to greater heating rates and final temperature increments. CT images reveal that microwave-induced damage originates from localized thermal stress concentration caused by dielectric heterogeneity among minerals,and the damage patterns are regulated by the spatial distribution of highly sensitive minerals. These findings deepen the understanding of mineral-microwave interaction mechanisms and provide a theoretical basis for parameter optimization and engineering application of microwave-assisted rock-breaking technology.