Performance evaluation of polygonal and cylindrical ball mills using
discrete element method
Abstract
Ball mills are commonly used in chemical and mineral processing
industries for particle size reduction. In mineral processing,
cylindrical drums with wear resistant materials are used various
operation scales. Polygon shaped mills have found application by
artisanal and small-scale miners (ASM) due technological and economic
reasons. Evaluating this kind of mills is key in improving or replacing
them based on technological data. A modest improvement in grinding
efficiency and mill durability can lead to significant economic and
environmental benefits. In this study, the performance of polygonal
shaped mills was evaluated and compared with cylindrical profiles
considering power draw, collision energy dissipation, relative wear and
operational stability. Discrete element method (DEM) was used to carry
out simulations to describe mechanical behavior of grinding media and
the interaction with the mill walls. Polygonal shaped mills without
lifters promoted more interparticle interaction with limited
centrifuging of particle even at higher speeds compared to cylindrical
mills without lifters. Installation of lifters in polygon increased
inter-particle collisions and reduce power draw and relative wear.
Cylindrical mill with lifters had high interparticle collisions similar
to polygonal profile with much lower cumulative relative wear and high
operational stability.