Scandium, yttrium and rare earth elements (SCYRE) are raw materials of increasing importance for modern technologies, and are included in the group of Critical Raw Materials for the European Union. They are mined from alkaline igneous rocks and from clayey soils derived from them. China produces more than 95% of SCYRE, and finding new sources has become a pressing need all over the world. On the other hand, Acid Mine Drainage (AMD) is commonly considered as a huge environmental pollution issue. However, SCYRE concentrations in AMD can be several orders of magnitude higher than in the rest of continental and marine waters. During the current EMPATIA project, we have observed that the SCYRE content in the acidic waters is entirely retained in the passive remediation systems.
More than a hundred abandoned mines and AMD producing site are found in the Iberian Pyrite Belt (IPB). They make the region a world scale paradigm of AMD and a natural laboratory to study the geochemistry of SCYRE. The present project is devoted to assess the feasibility of obtaining SCYRE from the AMD treatment. We propose to evaluate the flow and concentration of these critical elements in the mine drainages, their geochemical behavior in the streams, and their retention mechanisms in the remediation systems. If successful, in addition to the environmental benefits of its treatment, AMD is expected to run for hundreds of years and therefore, total reserves are unlimited.
Project staff: J. Bellés, A. Lozano, P. Hueros, L. Scheiber, R. Bartrolí, M. Cabañas