Geochemical signatures of rare earth elements and yttrium exploited by acid solution mining around an ion-adsorption type deposit: Role of source control and potential for recovery

作者：Haiyan Liu, Huaming Guo, Olivier Pourret, Zhen Wang, Maohan Liu, Weimin Zhang, Li Jun, Bai Gao, Zhanxue Sun, Pierre Laine · 发表于：The Science of The Total Environment · 年份：2021 · DOI：10.1016/j.scitotenv.2021.150241 · 被引用次数：63 · 研究领域：Geochemistry and Elemental Analysis、Mine drainage and remediation techniques、Extraction and Separation Processes

Elevated concentrations of rare earth elements and yttrium (REE + Y) in acid mine drainage (AMD) attract worldwide attention. However, the source and control of REE + Y distribution patterns in AMD remain unclear. Water, rock, sediment, and sludge samples were collected from an ion-adsorption deposit site to investigate REE + Y concentrations and distributions. The heavy REE (HREE)-enriched patterns of the AMD resulted from preferential desorption of HREE in the clay-rich sediment strata, from which the REE + Y were ion-exchanged by an in-situ underground leaching process using ammonium sulfate brine. Free ions and sulfate complexes preserved REE + Y patterns and facilitated REE + Y mobility in the AMD leachate system. High concentrations of REE + Y occurred in the AMD, and decreased progressively through nitrification-denitrification and coagulation-precipitation procedures in a water treatment plant . Concentrations of REE + Y were one to three orders of magnitude higher in AMD than those in groundwater, and were negatively correlated (r 2 = −0.72) with pH (3.8 to 8.7), suggesting that an acid desorption from minerals contributed the REE + Y to the AMD from the source rock. Normalized REE + Y patterns showed enrichments of HREE over light REE (LREE) and negative Ce anomaly. The distribution patterns were relatively constant for all water samples, despite their huge difference in REE + Y concentrations. This suggested a limited impact of preferential precipitation of LREE ov...