New Insights into Milling Optimization Using Efficient Grinding Media Shape

The shape of grinding media is considered an important parameter affecting the overall milling efficiency of a tumbling mill, particularly in terms of energy demand and particle comminution. In this regard, media of various shapes have attracted increasing interest, and their performance has been the subject of comparative investigations with conventional balls. A novel grinding media shape derived from the Reuleaux tetrahedron, called Relo grinding media, has been introduced. The present study examines the effect of Relo media relative to balls on load behavior and mill power draw across a range of mill speeds and media filling levels. The results show that the proposed grinding media shape may improve the grinding efficiency of tumbling mills in controlled laboratory tests by reducing mill speeds while maintaining a constant volumetric media charge and power draw. The results further indicate that the specific energy‒particle size relationship is influenced not only by the characteristics of the ore/material but also by the shape of the grinding media. Furthermore, a slightly lower fitted exponent in the energy–size relationship was obtained for Relo media compared with balls, although the difference was within the associated uncertainty. Under the examined conditions, Relo media resulted in a lower operating Work Index for the tested limestone.