· The formula for calculating shaft power | ball mill length: P = x C X J X V cr x (1 – ) x [1 – / 2 9 – 10Vcr] x x L x D Where: P = Shaft Power | Ball Mill Length J = Volume Load Percentage V cr = % Critical Speed sg = Bulk Density L = Mill Length D = Mill Internal Diameter. Let's solve an example; Find the shaft power | ball mill length when the volume load ...