Experimental Evaluation of Power Requirements for Wet Grinding and Its Comparison to Dry Grinding

The grinding operation is the most energy-consuming stage in the production of copper in mining facilities, as well as a major component in the cost of production. Therefore, deriving the relationship between the power requirements and the mill operating conditions is of interest, both during planning/design of a new grinder and during its operation. In a previous related paper, the authors reported the results of an extensive testing program to obtain the power-speed curves in a 60-cm diameter pilot mill during dry grinding. In this study, the power-speed curves obtained during wet grinding are reported using the same setup and charge conditions. Three different water-to-gravel ratios were tested and the effect of the water content on the power demand was obtained. In addition, the power demand during wet grinding is compared with the power obtained during dry grinding for the same operating conditions. A wet-dry power factor is proposed to obtain the estimated power during wet grinding from tests during dry grinding. Evaluations performed in the pilot mill showed estimated power errors below 6%.