The Development of Microwave Assisted Machineries to Break Hard Rocks

Novel rock breakage techniques are becoming more viable. According to a major research report on explosive free rock breakage (EFRB) completed by the authors and others, the use of microwave energy was highlighted as a high potential technique in assisting the breaking of hard rocks. Microwave energy, as a thermal energy which is capable of inducing micro cracks, is a technology that is growing fast in mineral processing and ore comminution applications. Recently, use of microwave has been evaluated as a possible avenue for spatial and terrestrial drilling applications and full face tunneling (TBM) or rock breaking machines. As part of an overall research on use of microwave in rock breaking systems, the influence of microwave energy on the mechanical properties of some common hard rock types is reported. Experimental and simulation results underline the potential impact of the use of microwave energy in underground or surface excavation. This will also contribute economically when mine-to-mill operation is fully considered. Furthermore, the microwave assisted drilling machine which was developed at McGill University and its possible drill bit design is discussed. It also outlines the potential impact of a future microwave assisted tunnel boring machine enhanced with microwave and its performance.