ASSESSMENT OF MICROHYDRODYNAMIC AND POPULATION BALANCE MODELING OF WET STIRRED MEDIA MILLS

As ore grades have been steadily decreasing, finer grinds are required to produce liberated minerals; hence, owing to their higher energy efficiency as compared with the conventional ball mills, wet stirred media mills are being used in the mining industry increasingly. This theoretical study aims to present a critical analysis of the recent advances in the simulation of wet stirred media milling (WSMM) with a focus on microhydrodynamic model (MHDM) and population balance model (PBM) for simulation and optimization. The MHDM allows for estimating the frequency of particle compressions between the milling beads and the rate of energy dissipation during the deformation of the particles. On the other hand, the PBM allows for predicting product particle size distribution (PSD) for a given feed PSD, following the estimation of the breakage parameters. After presenting their fundamental equations and salient features, their capabilities and pros/cons were critically analyzed. As a major novelty, two limiting solutions of the MHDM and an explicit expression for the dependence of the granular temperature to process-suspension properties through power density were derived. A future research direction for connecting the MHDM and the PBM was highlighted for advanced simulation-optimization-scale-up of the WSMM for ore milling.