Numerical and experimental analysis of fully coupled electromagnetic and thermal phenomena in microwave heating of rocks

Enhancement of mineral resources exploitation efficiency is one of the main targets identified by the mining industry. However, rock fragmentation, including excavation and comminution, is among the most energy-intensive activities imposing a substantial economic burden on the industry. The microwave pre-treatment technique has offered promising solutions in pre-weakening rocks and ores. This paper investigates the fully coupled electromagnetic and thermal effects of microwave treatment of rocks. A numerical simulation tool based on the finite element method is developed to simulate the microwave-treatment process occurring within the microwave cavity. Temperature-dependent dielectric properties are employed to ensure a bi-directional coupling between the interfaces. The simulation results are quantitatively and qualitatively compared with experimental investigations and validated with less than 3% numerical error.