ABSTRACT

One of the main merits of using High Pressure Grinding Rolls (HPGR) is particle weakening, which leads to less energy consumption at downstream grinding processes. Normally, HPGR feed contains various minerals with different weakening behaviors. Therefore, understanding the difference between particle weakening behavior in pure and multi-component feed grinding by HPGR is very important. In the current study, the difference of particle weakening behaviors in pure and mixture feed grinding by HPGR was investigated. To this purpose, the pure and different mixture ratios of magnetite (hard component) and calcite (soft component) minerals were comminuted by HPGR under three different pressures. After grinding, particles breakage behavior was investigated based on the relation of consumed energy and the particle size distribution of products. Particle weakening was studied through measuring changes in fundamental breakage and deformation parameters by Impact Load Cell (ILC). It was concluded that, at pressures resulting in breakage saturation state, the weakening of soft component in mixture feed grinding is more than grinding alone, but the changes in weakening of hard component in the mixture and pure feed grinding are insignificant. It was observed that the weakening of soft component particles in pure feed grinding are 15%, and by increasing hard component to 50 V%, their weakening increases by 19%. It resulted that the presence of hard components led to more energy consumption in soft component breakage and decreased energy dissipation toward particles deformation, leading to an increase of induced damage to soft component particles.

摘要

使用高压研磨辊 (HPGR) 的主要优点之一是颗粒减弱，这导致下游研磨过程的能源消耗更少。通常，HPGR 饲料含有各种具有不同弱化行为的矿物质。因此，了解 HPGR 纯和多组分进料磨削中颗粒弱化行为的差异非常重要。在目前的研究中，研究了 HPGR 在纯饲料和混合饲料研磨中颗粒弱化行为的差异。为此，采用 HPGR 在三种不同压力下粉碎了纯磁铁矿（硬组分）和方解石（软组分）矿物的不同混合比。研磨后，根据消耗能量与产品粒度分布的关系，研究颗粒破碎行为。通过使用冲击力传感器 (ILC) 测量基本断裂和变形参数的变化来研究颗粒弱化。得出的结论是，在达到破碎饱和状态的压力下，混合料磨削中软组分的弱化程度大于单独磨削，但混合物中硬质组分的弱化程度变化不明显。观察到在纯饲料研磨中软组分颗粒的弱化为 15%，而将硬组分增加到 50 V%，它们的弱化增加了 19%。结果表明，硬质组分的存在导致软质组分破碎时的能量消耗增加，减少了对颗粒变形的能量耗散，导致对软质组分颗粒的诱导损伤增加。