Mobility of rare earth elements in AMD-precipitates, Iberian Pyrite Belt (SW Spain)

Abstract

Rare earth elements (REE) were analyzed in surface waters, acid mine waters, and extracts of the mineral precipitates from Iberian Pyrite Belt. NASC (North Atlantic Shale Composition) normalized REE patterns show clear convex curvatures in middle-REE (MREE) with respect to light- and heavy-REE. Moreover, most of the AMD-precipitates release heavy-REE (HREE) to the solution during dissolution experiment, indicating that these minerals retain HREE predominantly from the water and provide REE fractionation along the series. Concentrations of the REE in water and acid mine drainage samples were in the range of 568 ng/L and 2580 µg/L, and significantly higher than previously reported concentrations of the surface waters from the Iberian Pyrite Belt.