Compatibility of slurry wall backfill soils with acid mine drainage

Kashir, Mansor; Yanful, Ernest K.

doi:10.1016/s1093-0191(00)00027-7

Cited by 16 publications

(6 citation statements)

References 24 publications

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“…When CaCO 3 is present in the soils the acidity is neutralized, the oxidation of Fe 2+ to Fe 3+ proceeds rapidly (Singer & Stumm, 1968), iron precipitates and the calcium and sulphate ions form gypsum (Ritsema & Groenenberg, 1993; Kashir & Yanful, 2000):…”

Section: Introductionmentioning

confidence: 99%

Pollution of carbonate soils in a Mediterranean climate due to a tailings spill

Simón

Dorronsoro

Ortíz

et al. 2002

European J Soil Science

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SummaryThe retention walls in a pond containing the residues from the pyrite mine of AznalcoÂ llar (southern Spain) broke open on 25 April 1998, spilling approximately 6 Â 10 6 m 3 of polluted water and toxic tailings, which affected some 55 km 2 . Drying and aeration of the tailings resulted in oxidation, forming an acidic solution with high pollutant contents, the effects of which were studied in a calcareous soil. The infiltration of this solution markedly affected only the first 12 mm of the soil, where strong acidification caused the weathering of the carbonates, and where the fine mineral particles were hydrolysed. The SO 4 2± ions in the acidic solution precipitated almost entirely at this depth, forming gypsum, hydroxysulphates and complex sulphates. The Fe 3+ ions also precipitated there, mainly in amorphous or poorly crystallized forms, adsorbing to As, Sb, Tl and Pb dissolved in the acidic solution. The Al 3+ ions, though partly precipitating in the acidic layer, accumulated mostly where the soil pH exceeded 5.5 (12±14 mm in depth). They did so primarily as amorphous or poorly crystallized forms, adsorbing to Cu dissolved in the acidic solution. The Zn 2+ and Cd 2+ ions accumulated mainly at pH > 7.0 (19±21 mm in depth), being adsorbed chiefly by clay mineral. After 15 months, only the first 20 mm of the soil were acidified by the oxidation of the tailings and most of the pollutants did not penetrate deeper than 100 mm. Consequently, the speed of the cleanup of the toxic spill is not as important as a thorough removal of tailings together with the upper 10 cm of the soil.

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Section: Introductionmentioning

confidence: 99%

Pollution of carbonate soils in a Mediterranean climate due to a tailings spill

Simón

Dorronsoro

Ortíz

et al. 2002

European J Soil Science

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“…En estas condiciones, se aumenta el lavado eficaz del ión sulfato, lo que repercute, positivamente, en el mejoramiento de las propiedades químicas de estos suelos, disminuyendo la posibilidad de volverse a activar la acidez potencial y recuperar las condiciones iniciales de acidificación. Por otra parte, Kashir & Yanful (2000) encontraron que en presencia de carbonato de calcio, la acidez es neutralizada, el hierro precipita y el sulfato se une con el calcio y se forma yeso, que se insolubiliza parcialmente. De igual forma, existe otra posibilidad y es que los sulfatos pueden ser adsorbidos a medida que aumentan los tratamientos, ya que hay intercambio de iones SO 4 2por iones OH-, en la superficie de los óxidos de hierro y de aluminio.…”

Section: Resultados Y Discusiónunclassified

Alteración química de la solución de un suelo sulfatado ácido, con encalamiento y lavado en columna disturbadas

Caballero¹,

Fernández²,

Severiche³

2009

Rev. U.D.C.A Act. & Div. Cient.

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“…2) . In the soil samples within the layer, abundant gypsum formed (Ritsema and Groenenberg, 1993; Kashir and Yanful, 2000), while the peaks corresponding to carbonates strongly decreased. In no case was pyrite detected, revealing the complete lack of direct contamination by the tailings in the interior of the layer (this fact was corroborated by electron microscopy).…”

Section: Resultsmentioning

confidence: 99%

“…In the carbonate soils the penetration of the liquid phase from the tailings was strongly limited because the carbonates neutralized the acidity of the solution, the oxidation of Fe 2+ to Fe 3+ proceeds rapidly (Singer and Stumm, 1968), iron precipitates and the calcium and sulfate ions form gypsum (Ritsema and Groenenberg, 1993; Kashir and Yanful, 2000), precipitating most of the heavy metals and trace elements. Gypsum formation in these soils is therefore frequent both in the presence of carbonates as well as calcium from mineral alteration or from calcium adsorbed by the exchange complex (Van Breemen, 1973).…”

mentioning

confidence: 99%

Migration of Trace Elements from Pyrite Tailings in Carbonate Soils

et al. 2002

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In the carbonate soils contaminated by a toxic spill from a pyrite mine (Aznalcóllar, southern Spain), a study was made of a thin layer (thickness = 4 mm) of polluted soil located between the pyrite tailings and the underlying soil. This layer, reddish-yellow in color due to a high Fe content, formed when sulfates (from the oxidation of sulfides) infiltrated the soil, causing acidification (to pH 5.6 as opposed to 8.0 of unaffected soil) and pollution (in Zn, Cu, As, Pb, Co, Cd, Sb, Bi, Tl, and In). The less mobile elements (As, Bi, In, Pb, Sb, and Tl) concentrated in the uppermost part of the reddish-yellow layer, with concentration decreasing downward. The more mobile elements (Co, Cd, Zn, and Cu) tended to precipitate where the pH was basic, toward the bottom of the layer or in the upper part of the underlying soil. The greatest accumulations occurred within the first 6 mm in overall soil depth, and were negligible below 15 mm. In addition, the acidity of the solution from the tailings degraded the minerals of the clay fraction of the soils, both the phyllosilicates as well as the carbonates. Also, within the reddish-yellow layer, gypsum formed autigenically, together with complex salts of sulfates of Fe, Al, Zn, Ca, and Mn, jarosite, and oxihydroxides of Fe.

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Compatibility of slurry wall backfill soils with acid mine drainage

Cited by 16 publications

References 24 publications

Pollution of carbonate soils in a Mediterranean climate due to a tailings spill

Pollution of carbonate soils in a Mediterranean climate due to a tailings spill

Alteración química de la solución de un suelo sulfatado ácido, con encalamiento y lavado en columna disturbadas

Migration of Trace Elements from Pyrite Tailings in Carbonate Soils

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