The global energy transition from fossil fuels to renewable sources poses substantial challenges to increase metal production, including industry-critical rare earth elements (REEs). Environmental and social concerns obfuscate the production of these ‘green’ metals and only ∼1% of REE demand is met from recycling. This work highlights the potential for the ‘economic rehabilitation’ of the Mary Kathleen Mine, a relinquished uranium (U) mine with very high (∼3 wt%) total REE concentrations within the tailings storage facility (TSF). Leaching of the tailings revealed that approximately 5% of the REEs are water-soluble, suggesting the possibility for extraction. Using an water leach, the projected total REE recovery is >10,000 t, which would exceed the total amount of U recovered (7,532 t) during the initial mining operation. The proposed recovery would offer a truck-free mine, using solar energy and water recycling technologies to recover REEs from a waste source, reducing environmental contamination.

中文翻译：

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从铀尾矿中回收的水溶性稀土元素 (REE)

全球能源从化石燃料向可再生能源的转型对增加金属产量（包括行业关键稀土元素 (REE)）提出了巨大挑战。环境和社会问题使这些“绿色”金属的生产变得混乱，并且只有约 1% 的 REE 需求可以通过回收得到满足。这项工作凸显了玛丽凯瑟琳矿“经济复兴”的潜力，这是一个废弃的铀 (U) 矿，尾矿储存设施 (TSF) 内稀土元素总浓度非常高 (~3 wt%)。尾矿浸出表明大约 5% 的 REE 是水溶性的，这表明提取的可能性。使用水浸出，预计稀土元素总回收量 >10,000 吨，这将超过初始采矿作业期间回收的铀总量（7,532 吨）。拟议的回收将提供一个无卡车矿山，利用太阳能和水回收技术从废物源中回收稀土元素，从而减少环境污染。