The angle of repose and size segregation of iron ore granules: DEM analysis and experimental investigation
The angle of repose and size segregation of iron ore granules: DEM analysis and experimental investigation
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DOI：
10.1016/j.powtec.2017.07.045
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发表时间：
2017-10
影响因子：
5.2
通讯作者：
Chengzhi Li;T. Honeyands;Damien O’dea;R. Moreno-Atanasio
中科院分区：
文献类型：
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作者：
Chengzhi Li;T. Honeyands;Damien O’dea;R. Moreno-Atanasio
本文建立了一个离散元模型来研究铁矿石颗粒的堆积特性。从模拟中获得了表征颗粒堆积的两个重要指标，即休止角（用于堆积稳定性）和尺寸偏析指数。的休止角和尺寸偏析指数的模拟和实验的比较显示出良好的一致性，表明所开发的模型是能够预测堆形成过程中的铁矿石颗粒的行为。模拟结果表明，铁矿石颗粒的休止角受颗粒尺寸、滑动摩擦系数和滚动摩擦系数的影响较大。颗粒尺寸的减小或滑动或滚动摩擦系数的增大显著地增加了堆积过程中排出颗粒的动能耗散率。因此，观察到颗粒堆稳定性增加。模拟结果还表明，在水平方向上的堆中的铁矿石颗粒的存在显着的尺寸偏析。堆积体外段的平均粒径相对大于中心段。但在垂直方向上，由于多种偏析机制的相互作用，尺寸偏析并不明显。
We have developed a DEM model to study the packing characteristics of iron ore granules. Two important indices in characterising the packing of granules,i.e. the angle of repose (for packing stability) and a size segregation index, were obtained from the simulations. The comparisons of the simulated and experimental angle of repose and size segregation indices showed good agreement, demonstrating that the developed model is capable of predicting the behaviour of iron ore granules during pile formation. The simulation results show that the angle of repose of iron ore granules was greatly influenced by granule size, sliding and rolling friction coefficients. A decrease in granule size or an increase in either the sliding or rolling friction coefficients significantly increased the kinetic energy dissipation rate of the discharged granules during the packing process. Therefore, an increase in granule pile stability was observed. The simulation results also demonstrated the presence of significant size segregation of iron ore granules in the pile in the horizontal direction. The average granule size in the outer section of the pile was relatively larger than that in the central section. However, in the vertical direction, due to the interaction of multiple segregation mechanisms, size segregation was not clearly observed.