Distributions and Extraction of Rare Earth Elements from Coal and Coal By-Products

NETL is leading a research effort to investigate, characterize, and extract rare earth elements (REE) from coal and coal by-products, including coal ash. Characterization of geologic core samples, coal mine wastes, and coal ash has led to interesting findings on the mode of occurrence and fate of rare earth minerals, such as monazite, in coalbased materials. Mineral associations and elemental distributions have been investigated and results indicate that Th is associated with light rare earth elements (LREE), possibly as monazite, and Zr is associated with heavy rare earth elements (HREE), possibly as zircon. Preliminary extractions of REE from coal ash using 2M hydrochloric acid (HCl) and sodium hydroxide (NaOH) hydrothermal pretreatment have been investigated. Sodium hydroxide solution pretreatment followed by an acid digestion was shown to increase extraction of REE to nearly 90% for coal ash.

[1]  J. Hower,et al.  Valuable elements in Chinese coals: a review , 2018, Coal Geology of China.

[2]  Ronghong Lin,et al.  Enrichment of rare earth elements from coal and coal by-products by physical separations , 2017 .

[3]  J. Hower,et al.  Size-Dependent Variations in Fly Ash Trace Element Chemistry: Examples from a Kentucky Power Plant and with Emphasis on Rare Earth Elements , 2017 .

[4]  E. Granite,et al.  Analysis of Rare Earth Elements in Geologic Samples using Inductively Coupled Plasma Mass Spectrometry; US DOE Topical Report - DOE/NETL-2016/1794 , 2016 .

[5]  C. Ward,et al.  A review of anomalous rare earth elements and yttrium in coal , 2016 .

[6]  J. Hower,et al.  Petrology, Mineralogy, and Chemistry of Size-Fractioned Fly Ash from the Jungar Power Plant, Inner Mongolia, China, with Emphasis on the Distribution of Rare Earth Elements , 2014 .

[7]  K. Wagatsuma,et al.  Dissolution of Rare Earth Elements from Coal Fly Ash Particles in a Dilute H2SO4 Solvent , 2013 .

[8]  V. V. Seredin,et al.  Coal deposits as potential alternative sources for lanthanides and yttrium , 2012 .

[9]  M. P. Ketris,et al.  Estimations of Clarkes for Carbonaceous biolithes: World averages for trace element contents in black shales and coals , 2009 .

[10]  Angel Lopez-Soler,et al.  Synthesis of zeolites from coal fly ash: an overview , 2002 .

[11]  J. Hower,et al.  Enrichment of U-Re-V-Cr-Se and rare earth elements in the Late Permian coals of the Moxinpo Coalfield, Chongqing, China: Genetic implications from geochemical and mineralogical data , 2017 .

[12]  David A. Atwood,et al.  The rare earth elements : fundamentals and applications , 2012 .