Efficiency improvement of ball mill liners by simulation of balls and ore trajectory in Sarcheshmeh_copper complex

Tumbling mill liners transfer the energy to the mill charge and have a significant effect on the load behavior. A plant audit at the Sarcheshmeh_copper complex indicted that due to the inappropriate design of ball mills liners the liners wear and tear increased and the grinding efficiency decreased. With the objective of investigating the design of initial, current and proposed liners, the simulation of charge trajectory was performed by the GMT and KMPCDEM software packages. It was observed that the charge impact point for the current liners design was above the toe and on the shell liners. By simulation it was found that increasing the liner lifter face angle from 0 to 15° and the lifter height from 18 to 21cm could decrease the difference between the impact point and the toe and direct balls impact to liners. Given the promising results, the new liners were designed, constructed and installed in the ball mill 4. The result of sampling for a period of one liner life indicated that the amount of particles smaller than 75 microns for ball mill 4 product (proposed design) compared with the ball mill 3 (current design) increased by 2.5% and the liners life of the first half and second half increased by 18% and 20%, respectively.