Article
Environmental Sciences
Xuexian Li, Ruixue Zhang, Qingguang Li, Pan Wu, Huijun Ye
Summary: The study found that CMD in Guizhou coal mine areas contains varying concentrations of REY, with some CMD being enriched in critical-REY. The geochemical compositions of CMD and geological conditions are significantly correlated with the behaviors of REY in CMD, with elevated concentrations of dissolved REY found in acidic CMD.
SCIENCE OF THE TOTAL ENVIRONMENT
(2021)
Article
Environmental Sciences
Xuexian Li, Wenlang Qiao, Deng Chen, Pan Wu, Yixi Xie, Xue Chen
Summary: Anomalous concentrations of rare earth elements (REEs) were found in the acid mine drainage (AMD) from a coal-mine area in northern Guizhou, China. The claystone from the floor of the coal seam was identified as a potential secondary source of extractable REEs, which were mainly adsorbed by clay minerals. Further studies will focus on the extraction model and economic benefits of REEs from the claystone samples.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Article
Energy & Fuels
Emine Cicioglu Sutcu, Sinem Senturk, Kemal Kapici, Nezihe Gokce
Summary: The study of mineral and rare earth element distributions in the Tuncbilek coal mine in Turkey revealed quartz, kaolinite, and dolomite as the most abundant minerals. The concentrations of certain rare earth elements were found to be higher than the World brown coal averages, with different distributions of LREY and HREY concentrations observed in different areas of the coal basin. The coal layers showed higher concentrations of HREY, while the clayey coal and clayey layers indicated LREY type enrichment.
INTERNATIONAL JOURNAL OF COAL GEOLOGY
(2021)
Review
Engineering, Chemical
Orevaoghene Eterigho-Ikelegbe, Hamza Harrar, Samson Bada
Summary: This article discusses the current status and potential strategies for recovering REEs from coal and coal discard, including the feasibility of physical beneficiation and hydrometallurgical leaching. It highlights the abundance of REEs in coal but also the need to address processing costs and knowledge gaps to advance REEs recovery from these sources.
MINERALS ENGINEERING
(2021)
Article
Energy & Fuels
Juanjuan Ma, Shuyan Li, Jinxi Wang, Shuting Jiang, Balaji Panchal, Yuzhuang Sun
Summary: This study optimized the culture conditions and bioleaching process of Aspergillus niger for the extraction of rare earth elements (REEs) from coal fly ash (CFA). It was found that organic nitrogen sources influenced the morphology and acid production capacity of A. niger, with oxalic acid being the main acid secreted (4.05 mg/L). The initial pH value was identified as the most influential factor affecting the bioleaching process, and by optimizing it, a leaching rate of 30.91% for total REEs in CFA was achieved. The main mechanism of REEs bioleaching by A. niger from CFA was speculated to be proton exchange and organic ligand complexation.
Review
Thermodynamics
Biao Fu, James C. Hower, Wencai Zhang, Guangqian Luo, Hongyun Hu, Hong Yao
Summary: This review critically summarizes recent progress in the study of REY in coal ash, evaluating the content, speciation, and extraction potentials of REY. It discusses the different forms, distribution behavior, and transformation mechanisms of REY in coal ash, and proposes possible retention mechanisms of REY by aluminosilicate glass at boiler temperature. The modification of REY speciation in fly ash by reactions with flue gas components and current extraction techniques for REY recovery from coal combustion ash are also highlighted.
PROGRESS IN ENERGY AND COMBUSTION SCIENCE
(2022)
Article
Energy & Fuels
James C. Hower, John G. Groppo, Cortland F. Eble, Shelley D. Hopps, Tonya D. Morgan
Summary: The Springfield coal in the Western Kentucky coalfield, a part of the Illinois Basin, ranges from high volatile A bituminous to high volatile C bituminous. The chlorine content closely follows coal rank, with highest concentration in high volatile A bituminous coals. V and Cr concentrations are high in top benches, particularly in higher rank sites. Zn and other elements show inconsistent enrichment patterns. Zr + Nb content is highest in high volatile C bituminous Spottsville quadrangle coals.
INTERNATIONAL JOURNAL OF COAL GEOLOGY
(2023)
Article
Nanoscience & Nanotechnology
Alexander T. Brown, Kenneth J. Balkus
Summary: There is a need for the development of new solid-phase adsorbents for element extraction from coal ash. High surface area carbon adsorbents are effective in adsorbing rare earth elements, and MFC-O has shown exceptional extraction capabilities for rare earth elements, thorium, and uranium. The binding properties of MFC-O make it an attractive material for selective extraction of rare earth elements from coal ash.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Metallurgy & Metallurgical Engineering
Jian-qiang Xue, Jian-xin Liu, De-zhi Huang, Wei-jian Zhou, Chun-ming Liu, Yu-sen Cao, Chuang-hua Cao
Summary: By analyzing the trace elements of coals, host-rocks, and wall-rocks from Bayili Coal Mine in Xinjiang, China, this study aims to trace the sources and evaluate the utilization prospects of REY in the coals. The distribution patterns of REY in the coals are divided into flat-type and heavy REE-enrichment type (H-type), while the host-rocks show middle REE-enrichment type (M-type) and H-type patterns. Almost all coal samples at Bayili Coal Mine are in a promising area on the diagram of percentage of critical elements vs ratio of sum of critical elements to sum of excessive elements, indicating good utilization prospects as by-product.
TRANSACTIONS OF NONFERROUS METALS SOCIETY OF CHINA
(2021)
Article
Engineering, Chemical
Shan Wu, Chao Bie, Hao Su, Yun Gao, Xiaoqi Sun
Summary: Two novel salicylic acid derivatives, OOBA and EHOBA, were synthesized for the extraction and separation of Y from ion adsorbed rare earth ores. The study found that OOBA exhibits similar extraction behavior to LREEs and has better selectivities for Y and other HREEs compared to common carboxylic acids. The extraction mechanism of OOBA was determined to be cation exchange. Furthermore, OOBA demonstrated advantages such as low stripping acid concentration, good cycle stability, and minimal loss in the extraction process. A simulated fractional extraction process was developed to separate Y from the Y-enriched HREEs feed liquid, resulting in a Y product with high purity and yield.
MINERALS ENGINEERING
(2022)
Article
Environmental Sciences
Lyen Castro, Julia Farkas, Bjorn Munro Jenssen, Stefania Piarulli, Tomasz Maciej Ciesielski
Summary: This study analyzed the distribution and anthropogenic contribution of 15 rare earth elements and yttrium (REY) in marine bivalves collected from two potentially polluted sites in Southern Norway. The results showed enrichment of light rare earth elements (LREE) over heavy rare earth elements (HREE) in the soft tissues of the organisms, as well as negative cerium and small positive gadolinium (Gd) anomalies. The study also found a high Gd anomaly downstream of the industry producing gadolinium-based MRI contrast agents, indicating biotic uptake of excess anthropogenic Gd.
ENVIRONMENTAL POLLUTION
(2023)
Article
Chemistry, Applied
Xiaorui Wang, Wei Cheng, Renda Xu
Summary: This study investigates the adsorption behaviors of rare earth elements (REY) on organic matter in coal through leaching tests and molecular simulation calculations. The results show that the organic matter in coal has a strong adsorption capacity for heavy rare earth elements (HREY) compared to light rare earth elements (LREY). The molecular simulation calculations also confirm the advantage of HREY in adsorption on organic matter. These findings are of great significance for the application of rare earth elements in coal-based resources.
JOURNAL OF RARE EARTHS
(2023)
Article
Environmental Sciences
Guoqiang Wu, Nan Shi, Tao Wang, Chin-Min Cheng, Jiawei Wang, Chunxiao Tian, Wei-Ping Pan
Summary: Coal ash has been identified as an important alternative source of rare earth elements (REEs). This study investigated the enrichment and occurrence form of REEs in coal ash, specifically in coal fly ash (CFA) from power plants. The findings revealed the higher enrichment ratio of REEs in CFA compared to ashes from muffle furnace, which was attributed to several factors including the fractionation of coal ashes, higher combustion temperature, and longer residence time of fly ash. The study also highlighted the important role of aluminum in the occurrence form of REEs in CFA. These experimental and computational results provide valuable insights for understanding the distribution of REEs in CFA and optimizing their extraction processes.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2022)
Review
Geochemistry & Geophysics
Johan Schijf, Robert H. Byrne
Summary: This paper reviews a long-term program on systematically measuring stability constants for yttrium and rare earth element complexes in seawater, aiming to better understand their speciation in the marine environment. Various analytical approaches were used, with detailed examinations of inorganic and organic ligands complexes.
Article
Energy & Fuels
Vinoth Kumar Kuppusamy, Maria Holuszko
Summary: The applicability of sulfuric acid baking followed by water leaching (ABWL) for enhancing rare earth element (REE) leaching recovery from coal tailings was investigated in this study. The results showed that ABWL significantly improved REE extraction, reaching around 80% recovery. During the ABWL process, rare earth minerals in the sample were transformed into easily soluble rare earth sulfates.
Article
Energy & Fuels
Luis F. O. Silva, Tito J. Crissien, Carlos H. Sampaio, James C. Hower, Shifeng Dai
Article
Energy & Fuels
Gordana Medunic, Mihaela Grigore, Shifeng Dai, Debora Berti, Michael F. Hochella, Maria Mastalerz, Bruno Valentim, Alexandra Guedes, James C. Hower
INTERNATIONAL JOURNAL OF COAL GEOLOGY
(2020)
Article
Energy & Fuels
Lei Zhao, Shifeng Dai, Robert B. Finkelman, David French, Ian T. Graham, Yongchang Yang, Jixiang Li, Pan Yang
INTERNATIONAL JOURNAL OF COAL GEOLOGY
(2020)
Review
Energy & Fuels
Shifeng Dai, Achim Bechtel, Cortland F. Eble, Romeo M. Flores, David French, Ian T. Graham, Madison M. Hood, James C. Hower, Vera A. Korasidis, Tim A. Moore, Wilhelm Puettmann, Qiang Wei, Lei Zhao, Jennifer M. K. O'Keefe
INTERNATIONAL JOURNAL OF COAL GEOLOGY
(2020)
Review
Energy & Fuels
Shifeng Dai, James C. Hower, Robert B. Finkelman, Ian T. Graham, David French, Colin R. Ward, Greta Eskenazy, Qiang Wei, Lei Zhao
INTERNATIONAL JOURNAL OF COAL GEOLOGY
(2020)
Article
Geology
Qiang Wei, Chaonan Cui, Shifeng Dai
ORE GEOLOGY REVIEWS
(2020)
Correction
Geology
Lei Zhao, Shifeng Dai, Victor P. Nechaev, Evgeniya V. Nechaeva, Ian T. Graham, David French
ORE GEOLOGY REVIEWS
(2020)
Article
Energy & Fuels
Na Xu, Robert B. Finkelman, Chuanpeng Xu, Shifeng Dai
Article
Geochemistry & Geophysics
Panpan Xie, Shifeng Dai, James C. Hower, Victor P. Nechaev, David French, Ian T. Graham, Xibo Wang, Lei Zhao, Jianping Zuo
Summary: Coals containing ammonium-bearing aluminosilicates are rich in critical elements. The nitrogen in these minerals likely originates from the decomposition of organic matter in coals under increased geothermal gradient from intrusions or hydrothermal fluids. The isotopic composition of nitrogen in the minerals and coals provides valuable insights into their formation and sources of critical elements.
Article
Geochemistry & Geophysics
Xiao Li, Shifeng Dai, Victor P. Nechaev, Ian T. Graham, David French, Xibo Wang, Lei Zhao, Jingtao Zhao
Summary: This paper reports the mineralogy and geochemistry of the Late Permian C1 Coal from Bole and Laibin mines in eastern Yunnan, Southwestern China. The coals are enriched in V, Co, Cu, Zn, and Se, which were mainly derived from the sediment-source region of the Kangdian Upland.
Article
Chemistry, Multidisciplinary
Na Xu, Robert B. Finkelman, Shifeng Dai, Chuanpeng Xu, Mengmeng Peng
Summary: Research findings suggest that the average linkage hierarchical clustering algorithm is more accurate and reliable for analyzing modes of element occurrence in coal from the Adaohai coal mine compared to other statistical methods. Analytical results on selenium, beryllium, and thallium indicate discrepancies with geochemical principles, such as substituting for phosphorus, being associated with rare earth elements, and occurring in iron sulfides, respectively.
Article
Engineering, Environmental
Chang Liu, Guoling Han, Bingwen Hu, Fushan Geng, Min Liu, Shifeng Dai, Yi Yang
Summary: This study uses electron paramagnetic resonance (EPR) spectroscopy to analyze CFA samples, identifying features of CFAs that can be recycled and proposing a method for fast screening of CFAs.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2021)
Article
Engineering, Environmental
Na Xu, Yuchen Yang, Mengmeng Peng, Qing Li, Chuanpeng Xu, Shifeng Dai
Summary: Combustion of coal produces coal combustion residues (CCRs) that contain naturally occurring radioactive materials (NORMs), which can be harmful to humans. The activity of CCRs depends on both the concentrations of radionuclides and the variations in coal ash yields. Therefore, determining threshold values for radionuclides in coal with different ash yield levels is significant.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2022)
Review
Geochemistry & Geophysics
Shifeng Dai, Sergey Arbuzov, Igor Yu Chekryzhov, David French, Ian Feole, Bruce C. Folkedahl, Ian T. Graham, James C. Hower, Victor P. Nechaev, Nicola J. Wagner, Robert B. Finkelman
Summary: Critical elements in coal and coal-bearing sequences have received great attention. Their enrichment in coals is generally attributed to within-plate volcanism and associated hydrothermal activity. However, Cretaceous coals are not commonly rich in critical elements, possibly due to intense igneous activity leading to acidification of terrestrial and marine waters.
Article
Engineering, Environmental
Zhen Wang, Shifeng Dai, Ellen A. Cowan, Matthew Dietrich, William H. Schlesinger, Qingru Wu, Mingxuan Zhou, Keith C. Seramur, Debabrata Das, Avner Vengosh
Summary: This study investigates the isotopic signatures and output rates of Pb in fly ash disposal in China, India, and the United States. It reveals that the isotopic composition of Pb in fly ash is similar to that of feed coal, allowing for easy tracing of Pb release into the environment. The disposal of Pb from fly ash in these countries has posed a significant environmental burden. Furthermore, coal fly ash contributes more to Pb accumulation than leaded gasoline in freshwater lakes.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2023)