Rare earth element resource evaluation of coal byproducts: A case study from the Powder River Basin, Wyoming
Rare earth element resource evaluation of coal byproducts: A case study from the Powder River Basin, Wyoming
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DOI：
10.1016/j.rser.2022.112148
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发表时间：
2022-04
影响因子：
15.9
通讯作者：
D. Bagdonas;A. Enriquez;Kipp Coddington;D. Finnoff;J. F. Mclaughlin;M. Bazilian;E. Phillips;T. McLing
中科院分区：
文献类型：
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作者：
D. Bagdonas;A. Enriquez;Kipp Coddington;D. Finnoff;J. F. Mclaughlin;M. Bazilian;E. Phillips;T. McLing
国内稀土元素来源和生产仅限于美国，目前主要依赖海外进行最终加工。国内日益增长的需求和资源安全导致对国内稀土元素资源的重大调查。这项工作的大部分重点是非常规潜在矿石库存，包括煤炭和煤炭副产品。本次调查的重点是燃煤发电厂产生的灰烬等煤炭副产品。怀俄明州的保德河盆地拥有美国最大的能源生产煤炭储量，约占美国开采的所有动力煤的 40%。在这项工作中，在第一节中，我们研究了煤炭副产品的稀土元素浓度，并将这些数据与当前的替代资源知识进行了比较。我们发现，本次调查中的煤炭副产品的稀土元素浓度始终足够高（高于当前能源部 300 ppm 的临界品位），值得考虑作为一种有前途的潜在资源。为了更好地了解资源勘探和矿体描述，还考虑了主煤层内的稀土元素行为。在第二部分中，我们使用净现值分析和第一部分中的稀土浓度数据评估了从粉河盆地煤炭副产品中提取稀土的经济可行性。我们计算了粉河盆地四个煤站的盈亏平衡灰分氧化产量和投入单位成本。所有四个站点的收支平衡单位成本都高于传统稀土元素矿山报告的矿山到氧化物的运营成本。这是一个充满希望的结果，特别是考虑到从开采的材料中提炼稀土比从灰烬中提炼稀土的成本更高。结果对稀土价格高度敏感：鉴于长期价格较低，这四个站都无法实现收支平衡。第三节总结了稀土元素资源开发方面的联邦政策考虑因素。政策制定的历史，最近关注稀土元素特定资助立法，与本文第一节和第二节相结合，表明怀俄明州煤炭副产品的开发存在巨大机遇，作为当前国内稀土元素短缺和战略需求的部分解决方案。
Domestic Rare Earth Element sources and production are limited in the United States and currently rely on final processing overseas. Increasing demand and resource security domestically has led to significant investigation into rare earth element domestic resources. Much of this work focuses on unconventional potential ore stocks, including coal and coal byproducts. This investigation focuses on coal byproducts generated as ash from coal burning power stations. Wyoming's Powder River Basin hosts the largest U.S. coal stocks for energy production, providing approximately 40% of all thermal coal mined in the U.S. In this effort, in section I, we have studied coal byproducts for rare earth element concentrations and compare these data to current alternative resource knowledge. We find that coal byproducts in this investigation are consistently high enough in rare earth element concentration (above the current Department of Energy 300 ppm cutoff grade) to warrant consideration as a promising potential resource. Rare earth element behavior within the host coal seams is also considered in an effort to better understand resource prospecting and ore body description. In Section II, we evaluate the economic feasibility of rare earth extraction from Powder River Basin coal byproducts using net present value analysis and the rare earth concentrations data from Section I. We calculate the break-even ash-to-oxide output and input unit costs for four coal stations in the Powder River Basin. All four stations have break-even unit costs that are higher than the mine-to-oxide operating cost reported for a traditional rare earth element mine. This is a promising result, especially given that it is more costly to refine rare earths from mined material than from ash. The results are highly sensitive to rare earth prices: given low long-term prices, none of the four stations can feasibly break even. Section III summarizes federal policy considerations in rare earth element resource development. The history of policy development, most recent focus on rare earth element specific funding legislation, paired with section I and II herein, suggest a robust opportunity for development of Wyoming based coal byproducts as a partial solution to current domestic rare earth element short falls and strategic needs.