Geochemical characteristics of coal mine discharge vis-¨¤-vis behavior of rare earth elements at Jaintia Hills coalfield, northeastern India

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• 作者：P.K. Sahoo^a ; ^b ; ^{prafulla.iitkgp@gmail.com} ; S. Tripathy^b ; ^{stripathy@iitkgp.ac.in} ; Sk. Md. Equeenuddin^c ; M.K. Panigrahi^b
• 关键词：Acid mine drainage ; Coalmines ; Secondary minerals ; Rare earth element ; Jaintia Hills
• 刊名：Journal of Geochemical Exploration
• 出版年：2012
• 出版时间：January 2012
• 年：2012
• 卷：112
• 期：Complete
• 页码：235-243
• 全文大小：1357 K

文摘

Geochemical characteristics of dissolved metals including the rare earth elements (REEs) in acid mine drainage (AMD) from Jaintia Hills coalfield, Meghalaya were studied. The mine drainage is characterized by low pH with high concentrations of Fe, Al, Mn, Ni, Pb and SO₄^{2?/sup> and REEs. The average total REE concentration in AMD is 714.7 ¦Ìg/L, which is much higher in comparison to Sitai coalmine drainage. Mine drainage and most of the stream waters from Jaintia coalfield showed a middle REE-enriched pattern when normalizing against North American Shale Composite (NASC). Speciation calculation revealed that Fe2+ is the predominant free cation whereas Fe3+ and Al3+ prevailed as their sulfate complexes. Further, in REE species, REE-sulfate complex (LnSO₄+) accounts for > 62 % , while free metal (Ln3+) accounts for 24 % to 40 % . REE pattern indicates that streams are highly impacted by the AMD. Geochemical modeling indicated the supersaturation of various Fe or Al bearing secondary minerals, which possibly control the mobility of metals and REEs.}