Author(s)

Maria-Ondina Figueiredo, Teresa Pereira da Silva, João Pedro Veiga, Daniel de Oliveira, Maria João Batista

CENIMAT/I3N, Faculty of Sciences and Technology, New University of Lisbon, Campus da Caparica, Lisbon, Portugal.
CENIMAT/I3N, Faculty of Sciences and Technology, New University of Lisbon, Campus da Caparica, Lisbon, Portugal; Unit of Mineral Resources and Geophysics, National Laboratory for Energy and Geology, Amadora, Portugal.
Unit of Mineral Resources and Geophysics, National Laboratory for Energy and Geology, Amadora, Portugal.

Rhenium is a very scarce element, occurring in the Earth's crust mainly carried by molybdenite (MoS2). Due to a very low availability comparative to actual industrial demand, rhenium is nowadays one of the most expensive mineral commodities and an increased interest is focused on ex- ploring residues resulting from a long-term mining, particularly of sulphide ore deposits. It is therefore noteworthy to assign the presence of rhenium (in a concentration up to 3 ppm) in the waste materials from the old sulphur factory at the abandoned mine of Sao Domingos (Iberian Pyrite Belt, Southeast Portugal), exploited since the Roman occupation of Iberia. Aiming at a potential sustainable recovery of rhenium as a by-product, X-ray near-edge absorption spectroscopy (XANES) was applied to clarify the Re-binding and mode of occurrence by comparing Re L₃-edge XANES spectra obtained from mine waste samples (previously fully characterized by X-ray laboratory techniques) with similar spectra collected from Re-rich molybdenites (Mo_1-xRe_xS₂) and from Re-O model compounds configuring various valences and coordination environments of rhenium ions. Obtained results are commented, ruling out a possible Re-S binding and rather conforming with the binding of rhenium to oxygen in the analysed mine waste materials.

Mine Waste Materials By-Products; Iberian Pyrite Belt; Rhenium; XANES; Re L₃-Edge

Figueiredo, M. , Silva, T. , Veiga, J. , de Oliveira, D. and Batista, M. (2014) Towards the Recovery of By-Product Metals from Mine Wastes: An X-Ray Absorption Spectroscopy Study on the Binding State of Rhenium in Debris from a Centennial Iberian Pyrite Belt Mine. Journal of Minerals and Materials Characterization and Engineering, 2, 135-143. doi: 10.4236/jmmce.2014.22018.