Bucket–Coal/Rock Interaction Mechanisms of Hydraulic Shovels in Open-Pit Mines: A Review

Large-scale mining hydraulic shovels are critical loading equipment in open-pit mines, where bucket–coal/rock interaction governs digging resistance, bucket filling, energy demand, dynamic structural loading, and tribological wear. This review synthesizes evidence on coal–rock properties, digging trajectories, local fracture, granular filling, load transfer, field measurement, wear, and structural and operating-parameter optimization. Its contribution is a mechanism-based comparison of methods, assumptions, validation evidence, and limits of transfer across material, tool, bucket, and machine scales. The reviewed studies show that material properties, bucket geometry, and kinematics jointly influence fragmentation, filling, and load transfer, but reported optima and numerical predictions remain condition-dependent. Particularly important gaps are calibration after particle or geometric scaling and full-scale validation linking cycle-resolved load, fill, energy use, and structural response with cumulative wear. A staged validation framework and coupled structure–operation evaluation are proposed as research directions; they are not presented as experimentally established improvements for large mining shovels.