ABSTRACT

High Pressure Grinding Rolls (HPGR) is a high-energy efficiency device that has the ability to weaken the particle. This leads to lower energy consumption at subsequent grinding stages. Currently, no commonly used standard indices exist for predicting breakage, and weakening behavior of particles by HPGR. Accordingly, the current study mainly aimed at investigating the relationship between the common grindability/mechanical characteristics of rock (including work index, Brazilian tensile strength, elasticity module, and uniaxial compressive strength) and the breakage and weakening behaviors of HPGR products. For this purpose, six samples (pure calcite, pure magnetite, pure quartz, marmarite rock, travertine rock, and copper ore) with identical particle size distribution were comminuted by HPGR at three pressure force levels of 2.5, 4.5, and 7.5 MPa. Then, the breakage behavior of the samples was evaluated based on the size reduction ratio, followed by studying the weakening of particles by measuring changes in the fundamental breakage and deformation characteristics (mass-specific fracture energy and stiffness) by Impact Load Cell (ILC). The results revealed an excellent relationship between the breakage behavior of particles and their Brazilian tensile strength, as well as their weakening behavior and elasticity module. For particles with a higher module of elasticity (resistivity toward deformation), energy would be consumed for the formation of cracks and subsequently, particle weakening. In the case of particles with a lower module of elasticity, energy is probably dissipated as particle deformation, resulting in more cake formation and less weakening in particles.

摘要

高压研磨辊 (HPGR) 是一种高能效设备，具有削弱颗粒的能力。这可以降低后续研磨阶段的能耗。目前，没有常用的标准指标来预测 HPGR 对颗粒的破坏和弱化行为。因此，目前的研究主要旨在研究岩石的常见可磨性/力学特性（包括工作指数、巴西抗拉强度、弹性模量和单轴抗压强度）与 HPGR 产品的破碎和弱化行为之间的关系。为此，HPGR 在 2.5、4.5 和 7 三个压力水平下粉碎了具有相同粒度分布的六种样品（纯方解石、纯磁铁矿、纯石英、marmarite 岩石、钙华岩石和铜矿石）。5兆帕。然后，根据尺寸减小率评估样品的断裂行为，然后通过冲击力传感器 (ILC) 测量基本断裂和变形特性（质量比断裂能和刚度）的变化来研究颗粒的弱化. 结果揭示了颗粒的断裂行为与其巴西拉伸强度之间的良好关系，以及它们的弱化行为和弹性模量。对于具有较高弹性模量（变形阻力）的颗粒，能量将被消耗以形成裂纹并随后使颗粒弱化。在具有较低弹性模量的颗粒的情况下，能量可能随着颗粒变形而耗散，导致更多的饼形成和更少的颗粒弱化。基于尺寸减小率评估样品的断裂行为，然后通过冲击力传感器（ILC）测量基本断裂和变形特性（质量比断裂能和刚度）的变化来研究颗粒的弱化。结果揭示了颗粒的断裂行为与其巴西拉伸强度之间的良好关系，以及它们的弱化行为和弹性模量。对于具有较高弹性模量（变形阻力）的颗粒，能量将被消耗以形成裂纹并随后使颗粒弱化。在具有较低弹性模量的颗粒的情况下，能量可能随着颗粒变形而耗散，导致更多的饼形成和更少的颗粒弱化。基于尺寸减小率评估样品的断裂行为，然后通过冲击力传感器（ILC）测量基本断裂和变形特性（质量比断裂能和刚度）的变化来研究颗粒的弱化。结果揭示了颗粒的断裂行为与其巴西拉伸强度之间的良好关系，以及它们的弱化行为和弹性模量。对于具有较高弹性模量（变形阻力）的颗粒，能量将被消耗以形成裂纹并随后使颗粒弱化。在具有较低弹性模量的颗粒的情况下，能量可能随着颗粒变形而耗散，导致更多的饼形成和更少的颗粒弱化。