(378h) A Novel Multi-Scale Modeling Approach for Simulating the Evolution of Particle Size during Dry Milling

A multi-scale modeling approach is formulated which combines the use of the discrete element method (DEM) and population balance modeling (PBM) to simulate the evolution of particle size distribution (PSD) in dry milling. DEM is used to elucidate the effect of the microdynamic environment on particle breakage behavior which is input into the PBM to predict the evolution of the PSD. While DEM and PBM can be used in combination at early milling times to simulate the evolution of the PSD, PBM must be used exclusively at prolonged milling times when particle numbers exceed the computational limit of DEM. As a major novelty, the proposed intermittent coupled DEM‒PBM approach uses a non-linear PBM, instead of a time-dependent PBM, which explicitly accounts for the effect of the microdynamic environment through a so-called effectiveness factor. The effectiveness factor accounts for the effect of the evolving PSD on breakage behavior and can be used to more accurately predict the PSD within the non-linear PBM framework. This study has demonstrated that a non-linear PBM, whose parameters were calibrated using DEM at early milling times, is capable of predicting the PSD evolution during prolonged milling and potentially obviates the need for computationally expensive DEM simulations which cannot practically simulate the whole milling duration.