Discrete Element Method Optimization Simulation of Planetary Ball Mills Operating Conditions

Planetary mills have garnered significant attention in various fields of material science, nanotechnology, and engineering due to their ability to finely grind and mix materials at the nanoscale. The study of such mills is often performed by using empirical approaches for the optimization of experimental conditions. Modeling is possible based on simple physics involving the interaction of DEM (Discrete Element Method) simulations, offering the possibility of studying planetary mills with a much deeper understanding of the process. This study focuses on the numerical characterization of planetary ball mills in terms of different parameters such as angular velocity, number of balls, and ball size. The influence of such parameters on the energy spectra of the mill is then found via DEM simulation, which is very useful information for modeling the breakage or adhesion processes inside a mill or scaling up such experimental mills to industrial processes. Results show that from all the useful power, 65.4 % and 54.0 % go into ball-wall shearing collisions for both 1 cm and 0.3 cm balls. At around 0.5 cm balls, there seems to be a minimum as only 46.7 % goes into ball-wall shear collisions. Despite this, those types of collisions take more power than any other for all the cases studied, being a ball size that is closer to the optimal value. This research, then, acts as a bridge between lab-scale conditions, which are easier and more cost-effective to optimize, and large-scale production, where optimization tends to be costly and difficult. The present study provides an understanding of the tools required to produce novel nanomaterials.