Analysis of the Mechanism of Agglomeration during Wet Ball Milling by Using DEM-CFD Simulation

A simulation coupling Discrete Element Method (DEM) with Computational Fluid Dynamics (CFD) was conducted in order to analyze the mechanism of agglomeration during wet ball milling. From the simulation, although the volume of the agglomerates decreased with increasing the interparticle repulsive force, the particles agglomerated even when the repulsive force acted between the particles. In addition, the volume of the agglomerates increased or converged to a certain volume as the balls repeatedly approached, collided, and separated from each other. These tendencies of the simulated agglomeration behaviour are consistent with the features of the agglomeration that were reported by the previous experiments. This indicated that the simulation represented the particle behaviour when the agglomeration occurs during wet ball milling. Furthermore, the simulation analysis suggested that the agglomeration during wet ball milling occurs when the liquid flow during the balls separation compress the particles and the compression force exceeds the potential of the repulsive force between the particles.