The pressure distribution between the rolls in a HPGR (High Pressure Grinding Rolls) is usually expected to vary significantly in the axial direction due to the end effects at the end of the rolls. This is based on the idea that particles near the ends of the rolls are less well confined which makes them more mobile with reduced ability to be trapped and crushed. This can reduce the performance efficiency of a HPGR quite significantly. Experimental measurement of this axial pressure distribution and its consequences for the breakage efficiency, particularly at industrial scale, is very difficult. So little is known about its nature or how this may change with choice of confining structures (such as cheek plates). This problem is tractable using DEM to predict the coupled flow and breakage of particles within the HPGR. A replacement strategy is used where particles are broken when the applied force exceeds a size dependent limit. This allows the DEM model to capture the fracture dynamics sufficiently to allow flow and load prediction. The model is calibrated against an experimentally measured product size distribution and predicts very close agreement across the entire resolved range of particle sizes. This model is used to explore the pressure distribution and how this, and the coarseness of the particles, changes along the rolls. Two mechanisms are identified for producing breakage in the HPGR. For a HPGR with cheek plates the discharge mass flow rate is found to be nearly independent of axial position with the product size distribution being axially invariant. The frictional effects of the cheek plates lead to a moderate axial flow towards each end of the rolls that balances the reduced vertical flow to give axially very uniform discharge behaviour. Finally, it is shown that only small changes in the confining cheek plate locations are needed to allow significant axial bypass, strong axial variation of discharge mass flow rate and a coarser product.

通常预期由于辊端部的末端效应，在HPGR（高压研磨辊）中的辊之间的压力分布会在轴向方向上显着变化。这是基于这样的想法，即靠近辊子末端的颗粒的约束程度不太高，这使它们更具流动性，而被捕获和压碎的能力却降低了。这会大大降低HPGR的性能效率。这种轴向压力分布及其对断裂效率的影响的实验测量非常困难，特别是在工业规模上。关于其性质或随着限制结构（如颊板）的选择如何改变的知之甚少。使用DEM预测HPGR中颗粒的耦合流动和破裂，这个问题可以解决。当施加的力超过尺寸相关限制时，如果颗粒破裂，则使用替换策略。这使DEM模型能够充分捕获裂缝动力学，从而进行流量和载荷预测。该模型针对实验测量的产品尺寸分布进行了校准，并预测了在整个分辨的粒径范围内的非常接近的一致性。该模型用于探究压力分布，以及压力分布以及颗粒的粗糙度沿辊的变化。确定了在HPGR中产生断裂的两种机制。对于带有颊板的HPGR，发现排出质量流速几乎与轴向位置无关，并且产品尺寸分布在轴向上是不变的。颊板的摩擦作用导致朝向辊子各端的适度轴向流动，平衡了减小的垂直流动，从而产生了轴向上非常均匀的排出性能。最后，显示出只需要在限制颊板位置上进行很小的改变就可以实现明显的轴向旁路，排出质量流量的强烈轴向变化以及较粗的产品。