堆体结构对次生硫化铜矿柱浸的影响

摘要

Heap structure is the key effect of solution distribution inside heaps and copper leaching effect. To research the bioleaching law of secondary copper sulfide under different conditions of heap structure, this study selects coarse and fine particles and carry out indoor column leaching experiments with couple of dumping modes continued for 60 days, effectively simulating the couples structure in real heaps, analyzing the pore structure under different heap structures based on CT technology, researching the changing law of bacteria concentration, pH value, copper leaching rate with leaching time, and obtaining the relationship equation between leaching time and copper leaching rate. The results show that the effect of different heap structure on ore leaching is different, and it tends to be the best by using the uniform particle size ores, the copper leaching rate reaches 75.9% after being leached for 60 days, the solution is hard to infiltration vertically and leaching effect is poor when fine interlayers located in the lower portion of heaps, the copper leaching rate reaches 59.5%. On the contrary, the upper layer of fine particles plays a good diversion effect and leaching rate tends to be higher. In the later part of ore leaching, copper leaching rate reaches the peak under the effect of the physical deposition of muddy, quartz and other non-reactants, the chemical agglomeration of sulfur, jarosite and other reaction production layer, and the biological factors like extracellular polymeric substances (EPS) and so on.%堆体结构是影响堆内溶浸液分布均匀性和浸矿效果的关键.为探究不同堆体结构条件下次生硫化铜矿生物浸出规律,选取粗、细粒径两种矿石颗粒,开展多种筑堆方式的室内柱浸实验,为期60 d,有效模拟实际堆体的多种结构,并引入CT无损探测技术,分析不同堆体结构下孔隙特征,获取了细菌浓度、pH值、铜浸出率等变化规律,以及浸矿时间与铜浸出率的关系方程等.结果表明:不同堆体结构对于矿石浸出效果的影响程度不同,采用均一大粒径矿石筑堆时,矿石浸出效果最优;浸矿60 d后,铜浸出率达75.9%;当堆内含细颗粒层且其位于堆下部时,溶液下渗困难,矿石浸出效果较差,铜浸出率仅为59.5%;反之,细粒层位于上部时具有良好的分流作用,浸矿效果较优.浸矿后期,在泥质、石英等不反应物的物理沉积,硫、黄钾铁矾、硫化钙等反应产物化学胶结,胞外多聚物等生物因素的共同作用下,铜浸出率逐渐达到峰值.