Abstract Though many studies pertaining to heap leaching have been carried out to study the reaction kinetics in cylindrical columns, in the scaled up variants the extraction efficiency has not always complemented the laboratory expectations. Since heap leaching is a hydrometallurgical process, the reactions are contingent on the effective interactions between the two main phases (i.e. solid and the fluid). Thus, this work attempts to elicit the understanding of the liquid flow without the focus on the reactions as the prior imparts higher importance. A pseudo 2-D packed bed of 266 mm in length, 200 mm in height and 100 mm in thickness was employed in this work and subjected to X-ray computed tomography (XCT) imaging. XCT is typically used to identify the solid structures in a study specimen. The current study explores the inter-particle flow behaviour and pore networks of two packing types, namely, glass beads and ore particles. The inter-particle flow development at varied flow rates using medical XCT was attempted in this work by the addition of a clinical contrast agent. The same packed beds were subjected to laboratory experiments to determine the respective liquid drainage distributions. The flow model was proposed on a weighted random walk (RW) approach to ascertain the probabilistic behaviour of the gravity dominated flow features in the examined packings using the pore networks inferred from the XCT images. The model was able to generate comparable liquid drainage profiles for the examined packings, though the effect of flow rate was not captured. This approach could be used to specify operational parameters, such as drip emitter spacing, particle size and agglomerate size in heap leaching to enhance the overall extraction of the valuable metal species.

中文翻译：

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孔隙网络在堆浸过程中评估颗粒间流动的适用性

摘要 虽然已经进行了许多与堆浸有关的研究来研究圆柱柱中的反应动力学，但在放大的变体中，提取效率并不总是能满足实验室的预期。由于堆浸是湿法冶金过程，因此反应取决于两个主要相（即固体和流体）之间的有效相互作用。因此，这项工作试图引出对液体流动的理解，而不是关注反应，因为先前赋予了更高的重要性。本工作采用长 266 毫米、高 200 毫米、厚 100 毫米的伪二维填充床，并进行 X 射线计算机断层扫描 (XCT) 成像。XCT 通常用于识别研究样本中的固体结构。目前的研究探索了两种填料类型，即玻璃珠和矿石颗粒的颗粒间流动行为和孔隙网络。在这项工作中，通过添加临床造影剂，尝试使用医学 XCT 在不同流速下发展粒子间流动。对相同的填充床进行实验室实验以确定各自的排液分布。流动模型是在加权随机游走 (RW) 方法上提出的，以使用从 XCT 图像推断的孔隙网络来确定受检填料中重力主导的流动特征的概率行为。该模型能够为检查的填料生成可比较的液体排放曲线，但没有捕获流速的影响。这种方法可用于指定操作参数，