Soluble Catalysts for Copper Recovery from Low Grade Primary Copper Sulfide Ores

用于从低品位原生硫化铜矿石中回收铜的可溶性催化剂

• 批准号: RGPIN-2016-03782
• 负责人: Dixon, David
• 金额: $ 2.4万
• 依托单位: University of British Columbia
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=685030
• 关键词: Soluble; Catalysts; Copper; Recovery; Low

Roughly 80% of the world's copper comes from the copper sulfide mineral chalcopyrite, CuFeS2. Typically, chalcopyrite ores are concentrated and subsequently smelted to obtain high purity copper. However, the grades of these primary copper ores have been steadily decreasing, which renders this route less than economical for many of today's low-grade ores. A potential low-cost alternative to process low-grade copper ores is heap bioleaching. However, chalcopyrite is notoriously difficult to leach due to mineral passivation, and commercial application of heap bioleaching has thus far been limited to secondary copper sulfide (chalcocite, Cu2S) ores. Heap bioleaching of low-grade chalcopyrite ores (combined with solvent extraction and electrowinning, or SXEW) has been the “holy grail” of hydrometallurgy for many years, and several methods have shown some promise, including the use of extreme thermophilic microbes in hot heaps where pyrite is first oxidized to generate heat, and the use of chloride as a catalyst. However, hot heaps are unreliable and difficult to control, and chloride is extremely corrosive.******Recent work at UBC suggests that it is possible to catalyse the leaching of chalcopyrite with certain soluble species. Electrochemical tests on a chalcopyrite electrode showed that small amounts of a proprietary (albeit inexpensive and readily available) soluble organic compound (which will be referred to as MFD) depassivated the electrode. Preliminary results from column and tank leaching experiments show that MFD is a powerful catalyst in ferric leaching. Adding MFD prevented passivation and enhanced the leaching rate significantly. Also, a column of ore which had stopped leaching began to leach rapidly again upon addition of MFD.******These results are very promising. If MFD can depassivate chalcopyrite under heap leaching conditions, then this could render chalcopyrite ores as easy to heap leach as chalcocite ores. This would be a major breakthrough which fundamentally alters the economics of copper mining.******The proposed research will focus on developing a viable heap bioleaching process for chalcopyrite ores using MFD. Specific objectives include:*** 1 Conduct column bioleaching experiments with MFD to determine optimum process conditions*** 2 Culture iron and sulfur oxidizing bacteria to be resistant to MFD at the levels required*** 3 Refine analytical methods for measuring MFD concentrations in leach solutions*** 4 Determine the impact of MFD (if any) on copper SXEW*** 5 Measure the reaction kinetics of MFD-catalyzed leaching*** 6 Develop a comprehensive mathematical model of heap bioleaching with MFD*** 7 Develop a parallel technology for stirred tank bioleaching of chalcopyrite ores and concentrates*** 8 Determine the fundamental mechanism of the catalytic effect of MFD*** 9 Test alternative organic compounds which share the same functional groups as MFD***10 Test MFD on other important sulfide minerals**

世界上大约 80% 的铜来自硫化铜矿物黄铜矿 (CuFeS2)。通常，黄铜矿矿石经过浓缩并随后熔炼以获得高纯度铜，但这些原生铜矿石的品位一直在稳步下降，这使得这条路线成为可能。对于当今许多低品位矿石来说，处理低品位铜矿石的一种潜在的低成本替代方法是堆生物浸出。由于矿物钝化，黄铜矿很难浸出，迄今为止，堆生物浸出的商业应用仅限于低品位黄铜矿矿石的次生硫化铜（辉铜矿，Cu2S）矿石的堆生物浸出（结合溶剂萃取和电积，或）。 SXEW）多年来一直是湿法冶金的“圣杯”，有几种方法已经显示出一些前景，包括使用极端热堆中的嗜热微生物，黄铁矿首先被氧化产生热量，并使用氯化物作为催化剂。但是，热堆不可靠且难以控制，并且氯化物具有极强的腐蚀性。****** UBC 的最新工作。表明可以用某些可溶物质催化黄铜矿的浸出，对黄铜矿电极的电化学测试表明，少量的专有物质（尽管是少量的）。廉价且容易获得的可溶性有机化合物（以下称为 MFD）使电极去钝化。塔和槽浸出实验的初步结果表明，MFD 是铁浸出中的强大催化剂，可防止钝化并显着提高浸出率。此外，添加 MFD 后，停止浸出的矿石柱再次开始快速浸出。****** 如果 MFD 能够使黄铜矿去钝化，那么这些结果是非常有希望的。在堆浸条件下，那么这可以使黄铜矿矿石像辉铜矿矿石一样容易堆浸，这将是一个重大突破，从根本上改变铜矿开采的经济性。******拟议的研究将集中于开发一种可行的方法。使用 MFD 对黄铜矿矿石进行堆生物浸出工艺 具体目标包括：*** 1 使用 MFD 进行柱生物浸出实验以确定最佳工艺条件*** 2 培养铁和硫氧化细菌。在所需水平上抵抗 MFD*** 3 改进测量浸出溶液中 MFD 浓度的分析方法*** 4 确定 MFD（如果有）对铜 SXEW*** 5 测量 MFD 催化浸出的反应动力学*** 6 利用 MFD 开发堆生物浸出的综合数学模型*** 7 开发黄铜矿矿石和精矿搅拌槽生物浸出的并行技术*** 8 确定MFD*** 9 测试与 MFD 具有相同官能团的替代有机化合物***10 测试 MFD 对其他重要硫化物矿物的催化作用**