Investigating the contribution of wear caused by impact and abrasion in semi autogenous grinding mills

Milling is one of the most important operational stages in steel and copper processing. Liners and lifters are used inside mill to extend their life and to enhance the grinding and crushing efficiency. The wear of lifters is influenced by a range of parameters such as: media charge level and mill speed. In this work, the researcher used a pilot mill of 1m diameter and 0.5m length to investigate the influences of ball filling and the mill speed on the impact wear of lifters under wet condition. The contribution of impact wear and abrasive wear from the total wear was investigated with new mechanical test method. A copper ore smaller than one inch was used to prepare slurry at 60% solids concentration of mass and slurry filling U=1. The ball filling is 10%, 20% and 30% of mill volume at different mill speeds from 60% to 100% of the critical speed. It was found that while there is an increase in ball filling the wear impact decreases. The wear rate was maximum when the mill speed varied between 80% and 90% of the critical speed. To find out the role of impact on the wear, a mechanism was devised and installed on the pilot mill to prevent the cascade motion.