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| Format: | Artículo científico |
| Language: | en |
| Published: |
Universitat de Barcelona
2005
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| Online Access: | https://www.redalyc.org/articulo.oa?id=50530103 |
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Table of Contents:
- Dissolution of minor sulphides present in a pyritic sludge at pH 3 and 25º C J. Cama P. Acero Ciencias de la Tierra Galena Sphalerite Chalcopyrite Pyritic sludge Dissolution kinetics The steady-state dissolution rates of galena, sphalerite and chalcopyrite at pH 3 under oxygen saturated atmosphereand at 25ºC are obtained by means of non-stirred flow-through experiments. These dissolution rates arecompared with those estimated by dissolving pyritic sludge from the Aznalcóllar mining tailings composed ofpyrite and minor sulphides galena, sphalerite and chalcopyrite.Based on the respective release of Fe, Pb, Znand Cu, the steady-state dissolution rates of pyrite (RateFe), galena (RatePb), sphalerite (RateZn) and chalcopyrite(RateCu) are 6.33 ± 0.95 x 10-11, 1.2 ± 0.18x10-10, 1.3 ± 0.20x10-11 and 1.71 ± 0.25x10-11 mol m-2 s-1,respectively, yielding RatePb > RateFe > RateZn ≥ RateCu. Based on the release of metal and sulphur to solution,the stoichiometric ratios Pb/S, Zn/S and Cu/S are 4 ± 0.25, 1.2 ± 0.1 and 0.90 ± 0.05 for the respective dissolutionreactions of galena, sphalerite and chalcopyrite, which are higher than the ideal ones. These high valuesresult from a sulphur deficit in the output solutions attributed to the loss of H2S(aq) via gasification by whichH2S(aq) partially converts to H2S(g). Nevertheless, the Cu/Fe ratio is 0.95 ± 0.05 during chalcopyrite dissolutionat steady state, suggesting that chalcopyrite dissolves stoichiometrically. 2005 artículo científico 1695-6133 https://www.redalyc.org/articulo.oa?id=50530103 en http://www.redalyc.org/revista.oa?id=505 Geologica Acta: an international earth science journal application/pdf Universitat de Barcelona Geologica Acta: an international earth science journal (España) Num.1 Vol.3