Release of technology critical metals during sulfide oxidation processes: The case of the Poderosa sulfide mine (south-west Spain)

Extensive extraction of technology critical elements (TCEs) from the lithosphere and their use results in a growing dispersion and remobilisation of these elements within the environmental compartments. We investigated the concentration and mobility of different TCEs (rare earth elements (REEs), Sc, Y, Ga and Tl) in acid mine drainage (AMD) outflows from a massive sulfide underground mine in south-west Spain for around 2 years. High levels of TCEs were observed; average concentrations of 8.2 mg L-1 of REEs, 1.5 mg L-1 of Y, 80 g L-1 of Ga, 53 g L-1 of Sc and 42 g L-1 of Tl were reported, several orders of magnitude higher than those observed in natural waters. The TCEs source in the study site is primarily accessory minerals in the host rocks, although the contribution of Ga and Tl by sulfides cannot be discarded. A seasonal variability in TCEs is observed in AMD waters, although their maximum concentrations do not coincide with those of sulfide-related elements. TCEs seem not to be controlled by the precipitation of secondary minerals, but by the intensity of chemical weathering inside the mined zone. A positive correlation between REEs and the Si/Na+K ratio seems to indicate that these elements are linked to resistant minerals to weathering. © 2019 CSIRO.

Bibliographic Details

Main Authors:	Cánovas, Carlos R., Macías, Francisco, Olías, Manuel, Basallote, M. Dolores, Pérez-López, Rafael, Ayora, Carlos, Nieto, José Miguel
Other Authors:	European Commission
Format:	artículo biblioteca
Language:	English
Published:	CSIRO Publishing 2019-10-02
Subjects:	Rare earth element, Neodymium isotope,
Online Access:	http://hdl.handle.net/10261/202557 http://dx.doi.org/10.13039/501100000780
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