Characterization of secondary products in arsenopyrite-bearing mine wastes: influence of cementation on arsenic attenuation

Autor: Aurelio Sanz-Arranz, P. Villar-Alonso, A. Murciego, J. Medina-García, F. Rull-Pérez, E. Álvarez-Ayuso, S.C. Aldana-Martínez
Přispěvatelé: Álvarez Ayuso, Esther, Álvarez Ayuso, Esther [0000-0003-2243-8639]
Rok vydání: 2018
Předmět:
Zdroj: Digital.CSIC. Repositorio Institucional del CSIC
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ISSN: 1873-3336
Popis: 12 páginas, 5 figuras y 3 tablas.
The secondary products of an arsenopyrite-bearing mine waste dump were characterized in order to ascertain their mineralogical, chemical and environmental features and to appraise their role in the abatement of As in the environment. To this purpose, representative surface samples of weathered sulfides (including cemented phases) and hardpan samples were collected and studied by X-ray powder diffraction (XRD), polarized light microscopy, electron microprobe analysis (EMPA), micro-Raman spectroscopy and digestion, extraction and leaching methods. Scorodite, amorphous ferric arsenates (AFA), elemental sulfur, hydronium jarosite, goethite, hematite and hydrous ferric oxides were the secondary products identified in the mine wastes. The hardpan was mainly constituted by gangue minerals, including sulfides (arsenopyrite and pyrite/marcasite) with different weathering degrees, cemented by cracked yellow phases corresponding to AFA with Fe/As molar ratios of 1.14–1.85 and elemental sulfur. These cracked compounds were also the binding agent in the other cemented phases. Hydronium jarosite and Fe (oxyhydr)oxides were enriched in As, showing values of 0.19–3.98 and 0.81–7.49 wt.% As2O5, respectively. The As leachability and lability from hardpan and cemented phases were not decreased as compared to those from the other weathered phases not showing cementation in the mine waste dump.
The financial support to perform this study was provided by the Spanish Mining Company Saloro SLU (contract numbers: article 83-18LB0Ñ and 080102130007), which is greatly acknowledged.
Databáze: OpenAIRE