Towards optimising ball-milling capacity: Effect of lifter design

The effect of liner/lifter profile on kinetics of batch grinding and the milling capacity in general was assessed using mono-size quartz material of 30 × 40 mesh (−600 + 425 μm) as feed. The liner profiles tested were, (i) bevel with 60° lifter face angle to represent the new liners, (ii) bevel with 45° lifter face angle to represent the worn liners and (iii) worn bevel modified with cone-lifters. The tests were conducted under identical conditions to allow a comparative analysis of the results. In all cases, the breakage followed the first order hypothesis. The experimental size distribution data was well predicted by the S and B model, thus allowing for estimation of breakage and selection parameters (i.e., γ and aT) for the three liner situations tested. The optimised values of the specific rate of breakage, Si for the three liner profiles tested were 0.381, 0.287 and 0.365 min−1, respectively, which clearly indicates the benefit of cone-lifters. The breakage distribution function (Bij) values did not vary significantly with liner profile, which echoes the findings by other researchers.