Large particle effects in chemical/biochemical heap leach processes - A review

The application of heap leach technology to recovery of economically important metals, notably copper, gold, silver, and uranium, is wide-spread in the mining industry. Unique to heap leaching is the relatively coarse particle size, typically 12-25 mm top size for crushed and agglomerated ores and larger for run-of-mine dump leaching operations. Leaching from such large particles is commonly assumed to follow shrinking core type behaviour, although little evidence for the validity of this assumption exists. This review investigates the current state of knowledge with respect to the understanding of the characteristics and mineralogy of large particles and how these influence leaching in a heap context and the tools to characterize these. This includes the study of ore and particle properties, visualization techniques for ore characterization, the connection between comminution and leaching behaviour, as well as particle models within heap leach modelling. We contend that the economics of heap leaching are strongly governed by the trade-off between the slow rate and limited extent of leaching from large particles and the cost of crushing finer. A sound understanding of the underlying large particle effects will therefore greatly inform future technology choices in the area of heap leaching.     

高锑铋复杂含银物料中有价金属的综合回收

以某厂铜阳极泥处理后得到的高锑铋复杂含银物料为原料,采用甘油的碱溶液浸出的方法,对含银复杂物料中的铜、锑、铋等有价金属的浸出进行较为系统的研究并优化了相关的工艺条件。研究了NaOH浓度、C3H8O3浓度、液固比、反应时间与温度等因素对浸出的影响,在优化条件下浸出时,铜、铋、锑的浸出率分别为96.73%、96.44%、85.91%。     

Hydrometallurgical processing of nontronite type lateritic nickel ores by MHP process

The research work presented in this paper determined the optimum conditions at which nickel and cobalt could be obtained at maximum efficiency from the column leach liquor of the lateritic nickel ore existing in Gördes region of Manisa in Turkey by performing effective hydrometallurgical methods. This column leach solution was initially neutralized and purified from its basic impurities by a two-stage iron removal process, nickel and cobalt were precipitated in the form of mixed hydroxide precipitate from the purified leach solution by a two-stage precipitation method called “MHP” and a manganese removal process was performed at the optimum conditions determined experimentally. By decreasing manganese concentration with this process to an acceptable level yielding at most 10% Mn in hydroxide precipitate, it was possible to produce a qualified MHP product suitable to the current marketing and standard conditions. The experiments conducted showed that by maintaining recycle leaching with sulfuric acid at which 95% of Ni-Co could be recovered from the precipitates, about 81% of Ni and 63% of Co in the lateritic nickel ore (9.72 kg Ni/ton of ore and 0.28 kg Co/ton of ore) could be extracted as mixed hydroxide precipitate by MHP process.     

从贫锰矿中提取钪的试验研究

试验采用化学处理方法，通过硫酸浸出、浸出液萃取、有机相提取钪，萃取余液回收钴镍，净化液制碳酸锰。获得粗钪品位Ｓｃ２Ｏ３９６．７５％，回收率７５．５７％；钴镍混合精矿回收率８０％；碳酸锰含锰４３．７３％，回收率９０％。     

模拟高放玻璃固化体的抗浸出性研究

本文对高放废物氧化物包容量为20wt％(含0.131mol/lSO_4~(2-))的GP-12/9B和GP-12/7B两种模拟高放玻璃固化体进行了ISO和MCC-1静态浸泡试验与Soxhlet动态浸泡试验,测定了元素浸出率和质量损失,研究了浸出率与浸泡温度和时间的关系。     

State of the practice review of heap leach pad design issues

The authors present a summary of the state of the practice of containment design in copper and gold heap leaching, focusing on recent advancements and how these applications differ from the more conventional landfill design practices. Advancements both within the Americas and worldwide are presented, including consideration of increasing heap depths, which are now approaching 150 m (with ore densities generally in the range of 1500–1800 kg/m³). Liner system performance under these pressures will be reviewed, including the latest developments in drainage pipe performance testing. The authors will also explore the recently emerging technology of using concentrated sulfuric acid pre-curing for copper ores and the related compatibility issues with conventional geomembrane materials.     

锌浸出渣浮选银的预处理研究

在锌精矿的沸腾焙烧过程中,温度高于650℃时,生成的氧化锌及氧化铁结合成铁酸锌,是一种难溶于稀硫酸的铁氧体,全部留在浸出渣中。高温高酸浸出条件控制愈好,铁酸锌被溶解的愈多,硫化锌被破坏的就愈彻底,渣含锌就愈低,金属回收率就愈高,而且有利于银的浮选。针对某冶炼厂湿法炼锌渣,采用高温高酸浸出和浮选的方法回收锌、银,高温高酸浸出液经过除铁得到的溶液返回锌系统回收锌,高温高酸浸出渣经过一次粗选两次精选三次扫选的试验流程,得到了品位达到了2017.45g/t,回收率达到78.44%的银精矿。     

载镉废啤酒酵母中金属镉的回收

以水洗废啤酒酵母为吸附剂,对废水中镉离子进行生物吸附及固液分离后,获得载镉废啤酒酵母。采用焙烧-酸浸-置换法回收"载镉菌体上的镉",在700℃焙烧24 h,菌渣中镉富集比为31.72,烧渣经15 g/L的硫酸、温度85℃条件下,浸出2 h,再用锌粒置换,得海绵镉,镉总回收率在98%以上。     

测定放射性废物固化制品浸出因子的建议(二)

本文给出了长方形固化制品扩散方程的解和有关的计算曲线。建议用浸出因子来表达浸出试验的结果。本文实际上是作者在本刊1982年第1期上所发表的文章的补充。     

基于灰色关联度的Leach算法的改进

Leach算法是无线传感器网络中应用最为广泛的分簇路由协议之一,但是该算法的簇头是随机产生的,有可能导致节点过早死亡,从而使整个网络崩溃。针对这一问题,提出一种基于优选簇头的改进Leach算法——gc Leach算法。改进算法引入灰色关联度思想对簇头进行分区选举,兼顾考虑了簇头的剩余能量以及位置分布,有效地避免了簇头分布不合理,以及簇头剩余能量过低导致的节点过早死亡的情况。仿真结果表明,改进后的gc Leach算法能够有效地降低网络能耗,延长网络生命周期。