Study of lifter wear and breakage rates for different lifter geometries in tumbling mill: Experimental and simulation analysis using population balance model

The lifter profile, mill speed and the amount of mill loading are the key elements influencing the load behavior, consequently the milling performance. In this paper, the effect of lifter face angle and height were studied for a lab scale ball mill. The effect of mill geometry on breakage rate and lifter wear rate was analyzed experimentally. A series of batch grinding tests were carried out using four different lifter (lifter I to IV) geometries and the rate of breakage was determined for each condition. Natural feed size of a top size 9.5 mm was ground in a Ø = 0.32 m test mill (Jb:40%25, w/w: 68%25, Nc: 55, 65, 75 and 85%25). The torque was recorded against the wear measurement of each lifter. The results confirmed the phenomena that all the measured torque/power values decreased after a certain value of Nc, that is 75%25 in this study. Lifter IV produced the highest rate of breakage at Nc of 65–75%25 and the lowest wear. Based on the experiments, a simulation of an industrial mill (3.5-degree lifter face angle) was done using the estimated values. The results showed that, similar to the batch tests, Lifter IV (12 mm height, 22.5-degree face angle) may increase the breakage rate and fine particle generation. The overall value of SSE was calculated to observe the variability in milling experiments. The value obtained was 26.18, with an error 3.73%25. © 2019 Elsevier Ltd

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