Abstract:The crack growth and distribution characteristics of rock particles composed of galena and calcite under microwave irradiation were studied via discrete element method. The effects of irradiation time, power density, energy consumption, and mineral size were analyzed. Research results demonstrated that tension crack is dominant in minerals. Mineral cracks can be divided into three types based on distribution characteristics and locations. The diffusion crack in calcite and the annular crack at the interface are the basic mechanisms of microwave-assisted ore crushing and grinding. Mineral cracks can be categorized into types following the relationship between crack number and irradiation time and energy consumption. Mineral crack has three growth stages under low power density and two growth stages under high power density. Given the same crack number in mineral particles, energy consumption decreases with increasing power density. However, energy consumption remains basically the same after increasing power density to a certain value. Similar with other ore crushing and grinding methods, microwave-assisted method cannot easily crush small minerals.