The effect of microwave treatment on the processing of mineral ores was investigated through simulations of microwave heating, thermal damage and confined particle bed breakage test on bonded-particle models. The simulations were undertaken on two-phase mineral ore consisting of a microwave-absorbing mineral in a non-absorbing matrix. The microwave heating was simulated by dissipating a volumetric heat source in the absorbent phase. The progeny size distribution and degree of liberation for the untreated and microwave treated ores after breakage tests were determined by undertaking image analysis of the model outputs. It was shown that microwave treatment at high power density considerably changed the progeny size distribution and enhanced the degree of liberation in confined particle bed breakage tests. It was also found that crushing velocity has a significant effect on both progeny size distribution and liberation, particularly for the ore treated at high power density. (C) 2011 Elsevier Ltd. All rights reserved.