Abstract Rare earth element (REE) resources in coal-related materials are vast. Assuming a coal production rate of 600 million short tons per year with an average REE content of 200 ppm, the potential REE resource is 120,000 tons per year, which is similar to the annual global production of REEs. Most of those resources that are associated with coal-related materials are found in association with the gangue or ash-based content from the coal ore. Under normal coal plant operation, the REEs often end up in refuse piles or tailings impoundments. In many cases, these REEs can be recovered at low cost using appropriate coal preparation, heap leaching, solvent extraction and/or selective precipitation, followed by subsequent separation and purification of individual REEs. In the present research, the processing approach uses a natural pyrite stream, which was removed during coal cleaning and used to enhance leaching. Bio-oxidation has been used commercially to accelerate leaching, and this approach has been applied to coal-based materials. The ferric ions generated from bio-oxidation oxidize sulfide minerals such as pyrite, which generates acid. Both acid and ferric ions are helpful for leaching REEs, as well as for removing residual sulfides, thereby preventing future acid mine drainage and related liabilities. It can be seen that, recovery of REEs from coal waste materials can enable coal producers to use untapped REEs resources to produce revenue and extend resource life while simultaneously reducing future environmental issues and costs.

中文翻译：

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从煤基资源中有效回收稀土元素：一种生物浸出方法

摘要 煤炭相关材料中的稀土元素（REE）资源丰富。假设煤炭产量为每年 6 亿短吨，平均 REE 含量为 200 ppm，则潜在的 REE 资源量为每年 120,000 吨，与全球每年的 REE 产量相似。大多数与煤相关材料相关的资源都与煤矿石中的脉石或灰分含量有关。在正常的燃煤电厂运行中，稀土元素通常最终进入垃圾堆或尾矿库。在许多情况下，这些 REE 可以通过适当的煤制备、堆浸、溶剂萃取和/或选择性沉淀以低成本回收，然后对单个 REE 进行分离和纯化。在目前的研究中，处理方法使用天然黄铁矿流，它在煤炭清洁过程中被去除并用于增强浸出。生物氧化已在商业上用于加速浸出，这种方法已应用于煤基材料。生物氧化产生的三价铁离子氧化硫化物矿物如黄铁矿，产生酸。酸和铁离子都有助于浸出 REE，以及去除残留的硫化物，从而防止未来的酸性矿山排水和相关责任。可以看出，从煤废料中回收稀土元素可以使煤炭生产商利用未开发的稀土元素资源产生收入并延长资源寿命，同时减少未来的环境问题和成本。这种方法已应用于煤基材料。生物氧化产生的三价铁离子氧化硫化物矿物如黄铁矿，产生酸。酸和铁离子都有助于浸出 REE，以及去除残留的硫化物，从而防止未来的酸性矿山排水和相关责任。可以看出，从煤废料中回收稀土元素可以使煤炭生产商利用未开发的稀土元素资源产生收入并延长资源寿命，同时减少未来的环境问题和成本。这种方法已应用于煤基材料。生物氧化产生的三价铁离子氧化硫化物矿物如黄铁矿，产生酸。酸和铁离子都有助于浸出 REE，以及去除残留的硫化物，从而防止未来的酸性矿山排水和相关责任。可以看出，从煤废料中回收稀土元素可以使煤炭生产商利用未开发的稀土元素资源产生收入并延长资源寿命，同时减少未来的环境问题和成本。从而防止未来的酸性矿山排水和相关责任。可以看出，从煤废料中回收稀土元素可以使煤炭生产商利用未开发的稀土元素资源产生收入并延长资源寿命，同时减少未来的环境问题和成本。从而防止未来的酸性矿山排水和相关责任。可以看出，从煤废料中回收稀土元素可以使煤炭生产商利用未开发的稀土元素资源产生收入并延长资源寿命，同时减少未来的环境问题和成本。