Abstract
Microwave technology can enhance the efficiency of rock weakening processes that are essential stages in the extraction of critical minerals. Microwave absorbed thermal energy induces micro-fractures at mineral boundaries, potentially leading to significant damage. In this study, a coupling between finite and discrete element methods is employed to investigate the electromagnetic-thermal-mechanical response of rock samples in a 2.45 GHz microwave cavity. Numerical results are validated both qualitatively and quantitatively through comparison with experimental benchmark tests, considering the overall heat absorption, temperature distribution, and overall strength reduction for a wide range of powers and exposure times. The study demonstrates that the degree of damage resulting from microwave irradiation is more noticeable at higher power levels and shorter exposure times. These findings imply that it is feasible to induce significant damage and reduce rock strength efficiently through microwave treatment prior to the extraction of critical minerals.