Geología y geoquímica de mina Poderosa. Evaluación de la fuente de tierras raras en los drenajes ácidos de mina

Abstract

The Iberian Pyrite Belt (IPB) is a large metallogenic sulfide province, where around 1 m3 /s of acid mine drainage (AMD) are generated,, increasing the acidity and adding metal(oid)s to acuatic enviroments, creating a great concern worldwide. In addition, AMD has recently been considered a strategic alternative as a secondary source of rare earths elements (REE), due to its high concentration and its preferential enrichment in medium REE (MREE). The origin of REE in AMD is still uncertain, although recent studies suggest that preferential leaching of MREE enriched mineral phases may trigger the REE input during water-rock interaction. To study this geochemical process in the IPB, Poderosa mine has been selected, due to its high REE content and the current historical data available from AMD. In this work, preliminary studies have been carried out, allowing the definition of different lithologies that conform the Poderosa mine area, and which could behave as a source of REE in AMDs. It has been concluded, considering further studies in the future, that the contribution of REE to the leachate must be produced by the combined interaction of AMD with various sources, as there are no samples with a REE pattern similar to AMD.