837 (Royston, 2012). Though packing benefits are to protect the liner plate from wear, it also affects the ore breakage mechanism and changes the trajectory of the grinding media and therefore reduces grinding efficiency. For liner inspections, to ensure safe SAG entry, extensive liner washing was commonly required to remove the packing which increased entry timeline. Figure 5 – Hi-Hi with 7° face angle, Bradken’s MILLSIM charge trajectory simulation at 10.8rpm, 30% mill charge and severe packing on shell liners. 2.3. Liner Wear Analysis Liner wear profile was monitored using 3D laser scans and ultrasonic thickness (UT) measurements, enabling comprehensive mapping of liner thickness throughout the entire liner life. This data formed the foundation for predictive wear-rate models, which were used for forecasting liner thickness at any point in time, leading to significantly improved planning of liner replacement intervals. Condition-based maintenance tools were implemented, followed by monthly 3D scans and UT measurements with visual inspections. Finally, as a further supplement, drone-based integrity inspections were initiated for full coverage of liner condition and structural health. In 2023, a SAG shell liner wear study was initiated, comparing the wear characteristics between original Hi-Hi and Hi-Lo liner configuration. The study analyzed lifter height and plate thickness. As shown in Table 1, the Hi-Hi lifter height presented higher wear rate than Hi-Lo configuration (14 to 19 mm/Mt) when throughput was below 2 Mt, while at throughput above 2Mt, both designs demonstrated similar wear rates of approximately 100 mm/Mt. Table 1 – Liner Lifter Wear Rate Ore Milled (Mt) Hi-Lo (mm/Mt) Hi-Hi (mm/Mt) 0 to 1 76 90 1 to 2 31 50 >2 98 101 Table 2 shows the liner plate wear rate, showing that the Hi-Hi design experiences a lower wear rate (12 mm/Mt) compared to the Hi-Lo design (15 mm/Mt) over the full liner life campaign. The packing condition associated with the Hi-Hi configuration contributes to an accelerated abrasion wear mechanism on the lifters, as well peening caused by media impact when low packing loads occur. However, as a result of the packing, a protective layer adhered over the liner plate, reducing abrasive contact and resulting in lower overall wear on the plate surface, driving an accelerated abrasion wear mechanism on the lifters.
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