2 MODELLING THE SPECIFIC GRINDING ENERGY AND BALLMILL SCALEUP Ballmill scale up (Bond’s Law)Data: zBond work index w i zFeed D f and product d size (both 80% cumulative passing) Result: The specific grinding energy w Mill power draw P = wT, where T the mill capacity Mill dimensions (from Tables or charts)

Ball Mill Design. A survey of Australian processing plants revealed a maximum ball mill diameter of meters and length of meters (Morrell, 1996). Autogenous mills range up to 12 meters in diameter. The lengthtodiameter ratios in the previous table are for normal applications.