Rare earth element distributions in rivers and sediments from the Erdenet Cu-Mo mining area, Mongolia

摘要

River water and sediments collected from the Erdenet, Gavil, and Khangal Rivers, near the Erdenet Cu-Mo mine were analyzed for their rare earth elements (REE) and yttrium (YREE) contents. Surface water samples were also collected from the tailing pond and ash pond of the mine, as well as in the seepage from the ash pond, where a part of the effluent flows into the Khangal river. The major chemical compositions of river and surface waters were found to vary slightly with water flow. The river water is Ca-HCO3-dominated in the upstream of the Erdenet and Gavil Rivers and ash pond; Ca-SO4-dominated in the tailing pond and seepage from the ash pond; and Ca-HCO3-SO4-dominated downstream of the Erdenet and Khangal Rivers. Both river and surface water exhibited a significant diatom content and the dissolved organic matter mainly comprise of fulvic acid-like materials, protein-like materials and microbial materials.