Rodrigo M. de Carvalho

Dynamic Modeling of Comminution Using a General Microscale Breakage Model

Abstract The traditional population balance model has been successfully used in the past to describe size reduction in industrial crushers and grinding mills, but presented limitations in scale-up from information obtained in the laboratory. The paper presents a general model that describes comminution of multi-component feeds in full-scale machines using a combination of information from breakage mechanisms, fundamental material characteristics, and the mechanical environment, allowing to overcome the limitations of traditional population balance model formulations. Since it is based on a detailed description of each stressing event, this model can be used to describe particle size reduction in different types of crushers and mills using the same fundamental material characteristics. In order to demonstrate its potential, the model has been applied to describe grinding in a ball mill, where the mechanical environment was predicted using the Discrete Element Method and breakage of particles was described using a model based on continuum damage mechanics. A good agreement was observed between measured and predicted results from a batch grinding test for a single-component feed. Simulations of the dynamics of grinding in a continuous mill demonstrated the effect of change in feed composition in both product size and fracture strength of particles discharged from the mill.