To represent the particle behaviors and to predict the product size distributions of coal breakage products by a double-roll crusher, a new combined breakage-agglomeration model has been constructed. The model utilizes a fair combination of individual models for two distinct phenomena, the breakage and the agglomeration which occur simultaneously in the double-roll crusher process. Thus, it is capable of representing the complicated reduction and growth in the particle size during the process. Model parameters were estimated from experimental data from single-size crushing tests. Using these parameters, product size distributions with distributed-size feed were predicted from the simulation and were compared to the experimental results. The simulated results show fairly close agreement with the experimental results with an acceptable degree of accuracy. The basic concept can be used for a description of the simultaneous breakage-agglomeration process, which involves particle shape changes during the process of agglomeration. (C) 2012 Elsevier B.V. All rights reserved.