06 Grinding Media Shape Efficiency

Given that comminution is one of the most energy-intensive stages in mining and metallurgical operations, improving grinding efficiency not only reduces electricity consumption and the associated CO₂ emissions but also promotes sustainable and environmentally responsible practices, thereby minimizing the overall environmental footprint of these sectors. Thus, the objective of this study is to evaluate the effect of grinding media shape on the grinding efficiency of copper-gold ore and improve the sustainability of mining and beneficiation operations. A series of tests were conducted in a laboratory ball mill using mono-size feed fractions at different mill speeds. Particle size distribution, specific energy input and first-order breakage kinetics were the factors that analyzed to assess the grinding performance. The experimental results indicate that grinding efficiency, considering both material breakage and energy consumption, is influenced by the shape of grinding media under varying grinding conditions. The use of alternatives to traditional balls, such as Relo Grinding Media (RGM), which are based on the Reuleaux tetrahedron, was found to perform better at lower speeds and for smaller feed sizes. The findings provide mechanistic insight into the grinding behavior of the tested media under controlled laboratory conditions and establish a basis for future scale-up investigations and evaluation of their applicability in larger-scale and industrial milling systems. Furthermore, the findings suggest that adopting a combined grinding strategy - using either conventional balls or alternative media depending on the operating conditions - could improve grinding efficiency while enhancing the sustainability of mineral processing operations.