Effects of grinding media shapes on load behaviour and mill power in a dry ball mill

Abstract

Little attention has been given to the study of grinding media shapes and how they affect load behaviour and power draw in grinding mills. To a large extent the focus has been on how grinding media shapes affect milling kinetics in terms of specific rate of breakage and breakage distribution parameterisation. This study investigated the effects of three media shapes (cylpebs, spherical and worn balls) on load behaviour and mill power draw at various mill speeds and load filling. An inductive proximity probe was used to determine the load orientation of the grinding media charge while a load beam enabled measurement of power draw. The variations in toe and shoulder positions among media shapes were observed. This was also reflected in the power draw. The power increases to a maximum with increasing mill speed for all media shapes. The maximum power draw was reached at different mill speeds for the three studied media shapes.