Abstract Due to the obvious differences of particle size, the ore particle segregation and stratification like fine interlayers (FIs) widely appeared in non-agglomerated heaps. In this paper, stratified stacks were set up by inserting FIs at the top, middle and bottom positions of stack, which were named TFIs, MFIs and BFIs respectively. The effect of these fine interlayers on copper extraction, pore evolution and surface damage were studied via the CT and SEM-EDS scanning methods. The results showed that the inserted FIs could be detrimental to the extraction efficiency. The peak extraction rate reached 73.2% in C4 (a uniform coarse stack), which was obviously higher than the peak extraction rate in stacks containing FIs, especially C3 (BFIs, 58.2%). Even though the average porosities of C1~C5 all increased after a 60-day leaching period, the bottom porosity of the stack tended to decrease whereas the top porosity increased, especially for the TFIs in C1. The damage to the ores surface negatively correlated with the located depth of FIs and was classified as severe damage (TFIs), extensive damage (MFIs) and pore-dominated damage (BFIs). This result shows that selective dissolution of minerals could have much more severe consequences in TFIs than in BFIs. Ore agglomerations that formed spontaneously during the leaching process could easily be observed in regions with undeveloped porosity especially in the BFIs.

中文翻译：

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分层堆垛对硫化铜萃取及表面形貌的影响

摘要 由于粒度差异明显，非团聚堆中广泛出现细小夹层（FIs）状的矿石颗粒偏析分层现象。在本文中，通过在堆栈的顶部、中间和底部位置插入 FI 来建立分层堆栈，分别命名为 TFI、MFI 和 BFI。通过CT和SEM-EDS扫描方法研究了这些精细夹层对铜提取、孔演化和表面损伤的影响。结果表明，插入的 FI 可能不利于提取效率。在C4（均匀粗堆）中的峰值提取率达到73.2%，明显高于含有FIs，尤其是C3（BFIs，58.2%）的峰值提取率。尽管 C1~C5 的平均孔隙率在 60 天的浸出期后均有所增加，堆叠的底部孔隙率趋于减少而顶部孔隙率增加，尤其是对于 C1 中的 TFI。矿石表面的损伤与FIs的定位深度呈负相关，分为严重损伤（TFI）、广泛损伤（MFI）和孔隙主导型损伤（BFI）。这一结果表明，矿物的选择性溶解在 TFI 中可能比在 BFI 中产生更严重的后果。在浸出过程中自发形成的矿石团块可以很容易地在孔隙度不发达的区域观察到，尤其是在 BFI 中。广泛损伤 (MFI) 和孔隙主导损伤 (BFI)。这一结果表明，矿物的选择性溶解在 TFI 中可能比在 BFI 中产生更严重的后果。在浸出过程中自发形成的矿石团块可以很容易地在孔隙度不发达的区域观察到，尤其是在 BFI 中。广泛损伤 (MFI) 和孔隙主导损伤 (BFI)。这一结果表明，矿物的选择性溶解在 TFI 中可能比在 BFI 中产生更严重的后果。在浸出过程中自发形成的矿石团块可以很容易地在孔隙度不发达的区域观察到，尤其是在 BFI 中。