Scale-up of Vertical Wet Stirred Media Mill (HIGmill) via Signature Plots, Stress Analyses and Energy Equations

HIGmill, which is a type of vertical wet operated stirred media mill, has found applications in mineral industry requiring fine grinding stage. As the technology has recently been developed, knowledge regarding to its operation is scarce. This study aims to fulfill this gap with its focus on scale-up of the mill from laboratory scale tests. Within the scope of the work, a HIGmill operated at copper regrind circuit was sampled at different operating conditions, i.e., tip speeds, solids contents and media filling. In parallel, laboratory scale tests using the identical HIGmill feed were run in a dry batch operated vertical stirred mill and ball mill. The two results were initially calibrated by changing the operating parameters of the laboratory mills. Afterwards, the feed samples were processed with the optimal condition of stirred mill and the results of both scales were compared. In this study, the applicability of three different scale-up methodologies, signature plot, energy equations and stress analyses were examined. The investigations showed that the procedures can be utilized to predict both the required energy and volume required for the milling application. The developed methodologies may be helpful for basic engineering purposes requiring sizing the mill.