Influence of ore size on the production of micro-sized ore particles by high-pressure gas rapid unloading

Abstract

Comminution of ore is a critical and energy-intensive process in mineral resource utilization. High-pressure gas rapid unloading (GRU) has emerged as a promising ore grinding technique, wherein high-pressure gas is injected into the ore and is unloaded at high speed to induce tensile failure inside the ore. Although the GRU is capable to achieve more efficient ore comminution with lower energy consumption compared to conventional methods, it is still in the early stages of development. The pulverization effect of different size ores is a crucial question needing to be revealed before the GRU industrial application. This study explores the impact of ore size on ore pulverization by GRU, using kaolin as an experimental material. Specifically, we discuss the following: 1. the impact of ore size on high-pressure gas infiltration, 2. the effect of infiltration time on ore pulverization, and 3. the effect of ore size on GRU-pulverized ore. The results indicate that the GRU pulverization method is highly applicable to kaolin, and different ore sizes have minimal effects on ore pulverization. Finally, we explain the insignificant size effect of GRU-pulverized ore by discussing the ore material length scale, deformation scale, and ore size. The conclusion may provide a basis for extending the GRU method from the experimental lab scale to a larger one. It may also provide a reference for applying GRU in kaolin comminution.