THE HIGH-INTENSITY NUTATING MILL - A BATCH BALL MILLING SIMULATOR

The nutating mill is a compact grinding mill of novel design, capable of very fast breakage rates per unit mill volume. It operates with a strong acceleration field to produce an intense grinding action, and is likely to find a wide range of applications - from autogenous milling to very fine grinding of hard materials. A simulation model for batch ball milling in the nutating mill been developed as a step towards continuous simulation of ball and autogenous milling in these mills. The simulator is based on a combination of experiments on laboratory and pilot-scale nutating mills, theoretical analysis of the forces involved in these mills, and adaptations of published scale-up equations for ball mills. The development of the simulator is described, with discussion of the methods used for predicting the effects of mill size and speed, ball size and density, and mill filling by balls and powder or slurry. By use of a practical example on wet milling it is shown that the batch grinding performance of a nutating mill can be predicted accurately by scaling up data measured in a small laboratory mill. © 1990.