trajectory and prevented stable packing formation. Collectively, the design fails to protect the liner plate contrary to conventional Hi-Lo liner performance where packing can be effectively controlled to the height of the low (“Lo”) lifters to effectively shield the liner plate from wear (Royston, 2006). It is recommended that the next Hi-Lo design incorporate key improvements. These include revised lifter spacing and inter-lifter profile (bucket volume) to reduce charge slippage, rebalanced lifter height and face angle to promote optimal charge trajectory while limiting impact severity and accelerated wear. These recommendations are consistent with stablished liner spacing and charge trajectory studies demonstrating the strong influence of lifter geometry on impact energy and wear rate (Powel, 2006; Royston, 2006). Also, increased lifter width to resist peening deformation and increased thickness plate to enhance wear life and fatigue resistance. The inclusion of symmetric liner bolting pads is also recommended to ensure a uniform load and reduce localized stresses in line with established liner design practices (Powell, 2006). 2.4. Liner Design Methodology In 2024, Clarabelle Mill launched an in-house liner design optimization project. The multi-disciplinary team consisted of maintenance, operation, process technology, processing research innovation group, mill liner supplier, mill reline contractor, mill reline liner handler manufacturer and liner bolt manufacturer. The liner design approach incorporated detailed wear analysis from historical Hi-Lo and Hi-Hi liner campaigns and chronic failure modes. A comprehensive Failure Mode and Effects Analysis (FMEA) was developed to identify liner failure mechanisms and establish action plans to mitigate them. In April 2024, with Vale’s procurement involvement, a ‘request for information’ process was initiated. Seven original liner manufacturers (OEM) were invited to participate in the liner design optimization project. After systematic technical evaluation of the concept design proposals, one OEM was selected in July 2024. Detailed engineering continued with the chosen OEM and was finalized by October 2024. The optimized liner design was installed in May 2025. Guidelines from a general design VDI 2221(Jansch, 2006) were followed. One of the most crucial steps was to identify components of the liner such as lifter and plate. Functions of each component were defined and integrated with key operational variables such as SAG rotational speed and volumetric charge them into the design expectations. The design criteria expectations were as follows: ● Liner service life—the liner system shall be designed to achieve a minimum service life equivalent to 3.2 million metric tons of ore processed or (6 months), with aligned wear performance and synchronized replacement intervals for the discharge-end (DE), shell, and feed-end (FE) liners. ● Failure mode mitigation—the design shall prevent or minimize known failure mechanisms, including peening of liner plates, pegging of apertures or grates, liner cracking, deflector cone bolting failure and excessive packing between liner lifters.
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