Pebbles are competent ore fragments that are difficult to further reduce in size in conventional comminution circuits, and their efficient treatment is essential for improving circuit stability and lowering downstream grinding energy consumption. In this study, pebbles from the Julong Copper Mine were used to optimize the key operating parameters for high-pressure grinding roll (HPGR)-based pebble treatment. A uniaxial piston compression device was employed to simulate the confined particle-bed breakage process in HPGR, and the effects of feed volume, moisture content, applied pressure, loading speed, and roll surface profile on pebble compression performance were systematically investigated. The compressed products were characterized by particle size distribution, fine fraction yields, and grinding energy indices. The results indicated that the optimal compression conditions were a feed volume of 240 cm3, a moisture content of 6%, a loading speed of 0.2 mm/s, and an applied pressure of 1000 kN. Under these conditions, the products exhibited higher fine fraction yields and lower grinding energy indices, indicating improved subsequent grindability. Moreover, among the tested roll surface profiles, the cylindrical studded platen with 60% coverage produced the best compression performance. The findings provide a useful basis for optimizing HPGR operating parameters for copper ore pebble treatment.
Wang et al. (Mon,) studied this question.