An Investigation on the Change of Control Screen Size in Work Index Estimation

摘要

Bond equation (1952) is significantly used in mineral processing for size reduction equipment designs and practices. To estimate the required energy, work index (W_i) represents the grindability of an ore/mineral, which is experimentally calculated using a specific lab-scale mill. In order to specify the effect of control screen size on W_i estimation, three different ores, Pb-Zn ore of Alam-Kuh, Cu ore of Sarcheshmeh and Dolomite of Abe-Garm region were sampled and 12 sets of tests were carried out, using 425, 212, 150 and 100 micron as control screen sizes. Results indicated that the W_i values for all three different ores increased with the increase of the control screen size. The relations between (P_i)~(1/2)/(P_i is the control screen size) and G_i (fines produced per revolution), P_i and P (the screen size through which 80% material passes) were linear. The constant of these linear equations were estimated, using regression technique.