Abstract The mining of non-ferrous metals produces the largest volume of metal-containing, extractive waste in Europe, and about 29% of all the waste produced in the EU-28. In the framework of the European project NEMO (Near-zero-waste recycling of low-grade sulfidic mining waste for critical-metal, mineral and construction raw-material production in a circular economy), new ways to valorize sulfidic tailings are being developed through the recovery of valuable metals and critical raw materials and the transformation of the residual in clean mineral fraction to be used for the mass production of cement, concrete and construction products. The first step of the NEMO concept consists of removing the sulfides remaining from primary bioleaching and extracting the metals in the residual material (known as ‘secondary ore’) using either enhanced bioleaching or an alkaline autoclave conversion processes. This paper focuses on one of the project case studies, the secondary ore, obtained from an operating heap leaching plant (Terrafame, Finland). This material still contains several sulfide minerals (pyrrhotite, pyrite, sphalerite, pentlandite, violarite, chalcopyrite) and significant amounts of metals (Zn, Ni, Cu, Co, rare earth elements). The study aimed to characterize the mineralogy of the secondary ore and perform bioleaching in 2 L-stirred tank reactors, with three microbial cultures growing at 42, 48 and 55 °C. These results were compared to abiotic experiments, performed under the same conditions. Nickel was released very quickly, suggesting that part of Ni dissolved in the primary heap was re-precipitated and remained in the secondary ore. By contrast, Cu dissolution was much slower but the kinetics were substantially improved when the temperature was increased to 55 °C. Cobalt dissolution kinetics were highly improved by the bacterial activity, whatever the consortium. This is consistent with the presence of Co in the pyrite in the secondary ore.

中文翻译：

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生物浸出再加工硫化多金属初级采矿残渣：金属浸出机制的测定

摘要 欧洲有色金属开采产生的含金属废料最多，约占欧盟 28 国产生的所有废料的 29%。在欧洲项目 NEMO（循环经济中用于关键金属、矿物和建筑原材料生产的低品位硫化矿废料的近零废物回收）的框架内，正在开发使硫化尾矿增值的新方法贵金属和关键原材料的回收以及清洁矿物部分的残余物的转化，用于大规模生产水泥、混凝土和建筑产品。NEMO 概念的第一步包括去除初级生物浸出中残留的硫化物，并使用增强的生物浸出或碱性高压釜转化过程提取残留材料（称为“二次矿石”）中的金属。本文重点介绍项目案例研究之一，即从运营中的堆浸厂（芬兰泰拉法姆）获得的次生矿石。这种材料仍含有多种硫化物矿物（磁黄铁矿、黄铁矿、闪锌矿、镍黄铁矿、紫铜矿、黄铜矿）和大量金属（锌、镍、铜、钴、稀土元素）。该研究旨在表征次生矿石的矿物学特征，并在 2 个 L 搅拌罐反应器中进行生物浸出，其中三种微生物培养物在 42、48 和 55 °C 下生长。这些结果与非生物实验进行了比较，在相同条件下进行。镍的释放非常快，这表明溶解在初级堆中的部分镍重新沉淀并保留在次级矿石中。相比之下，当温度升高到 55 °C 时，Cu 溶解要慢得多，但动力学得到显着改善。无论是哪种聚生体，细菌活性都极大地改善了钴的溶解动力学。这与次生矿石中黄铁矿中 Co 的存在是一致的。无论是哪种聚生体，细菌活性都极大地改善了钴的溶解动力学。这与次生矿石中黄铁矿中 Co 的存在是一致的。无论是哪种聚生体，细菌活性都极大地改善了钴的溶解动力学。这与次生矿石中黄铁矿中 Co 的存在是一致的。