Future Industries Institute , University of South Australia , Mawson Lakes , South Australia 5095 , Australia.
Department of Chemical Engineering , University College London , Torrington Place , London WC1E 7 JE , United Kingdom.
Anal Chem. 2019 Jan 15;91(2):1557-1562. doi: 10.1021/acs.analchem.8b04802. Epub 2018 Dec 24.
This paper reports on an ore-on-a-chip that enables efficient investigations of mineral leaching using real ore samples. Here, chalcopyrite (CuFeS) ore samples are cut, polished flat, and sealed against a polydimethylsiloxane microchannel. The leach solution is collected for analysis, and the ore sample is then recovered for surface analysis. Compared to conventional bulk-scale leach tests, the ore-on-a-chip allows for faster, more efficient screening of leach parameters using real ore samples obtained from mine sites. Insight and optimization of leach conditions is demonstrated here for chalcopyrite, which has been extensively studied, yet leach performance is still strongly dependent on the origin of the ore. Two grades of chalcopyrite were chosen for this study (moderate and high purity), and the effect of ferric ion concentration and pH was studied in moderate and high purity chalcopyrite ores, respectively. The leach rate of Cu was faster in the presence of ore impurities (moderate grade) compared to the higher purity ore under the same conditions. The results also suggest that Fe is preferentially leached in the early stages to form an iron-deficient sulfide, according to X-ray photoelectron spectroscopy. Longer leach studies (48 h) reported no measurable surface passivation for the conditions studied. The ore-on-a-chip offers a new approach of case specific leach studies, which will enable rapid and tailored optimization of leach strategies for mineral processing.
本文报道了一种矿芯芯片，可用于使用实际矿石样品高效研究矿物浸出。在此，选取黄铜矿（CuFeS）矿石样品进行切割、抛光平整，并密封在聚二甲基硅氧烷微通道中。浸出溶液被收集用于分析，然后回收矿石样品进行表面分析。与传统的批量浸出试验相比，矿芯芯片可使用从矿山获得的实际矿石样品，更快、更高效地筛选浸出参数。本文以广泛研究过的黄铜矿为例，展示了浸出条件的优化。然而，浸出性能仍然强烈依赖于矿石的来源。本研究选择了两种等级的黄铜矿（中等纯度和高纯度），分别研究了中等和高纯度黄铜矿矿石中三价铁离子浓度和 pH 值的影响。在相同条件下，含矿石杂质（中等纯度）的铜浸出速度比高纯度矿石快。X 射线光电子能谱分析表明，结果还表明，在早期阶段，铁优先浸出，形成铁不足的硫化物。更长时间的浸出研究（48 小时）表明，在所研究的条件下，表面钝化没有可测量的迹象。矿芯芯片提供了一种针对具体矿石浸出研究的新方法，将能够快速和定制化地优化矿物加工的浸出策略。
