The iron-coating role on the oxidation kinetics of a pyritic sludge doped with fly ash

Evaluation of heavy metal bio-availability from Almagrera pyrite-rich tailings dam (Iberian Pyrite Belt, SW Spain) based on a sequential extraction procedure

“…For instance, in this way Pérez-López et al (2007a) recently showed in labexperiments how the addition of a cover of fly ash (a strongly alkaline low-cost material from coal combustion) on a pyritic sludge tailing dam from the IPB favoured acid neutralization, metal retention in solution, and therefore, the improvement of the quality of the leachates. Under these conditions, Fe-precipitation as ferrihydrite forming a coating on the pyrite surfaces may also prevent the interaction between oxidizing agents and the pyrite grains, halting pyrite oxidation.…”

Geochemical evaluation of heavy metal migration in Pb–Zn tailings covered by different topsoils

“…The presence of a lime interlayer could reduce the mobility of Zn and Cd, and a clay interlayer was effective in preventing the migration of Pb and Zn but had less impact on Cd. Lime can react with water and CO 2 to form a hardpan layer that could act as an oxygen and water diffusion barrier (Blowes et al, 1991;Pérez-López et al, 2007b;Lin, 1997). In addition, hydrated lime could stabilize the metals released from tailings and impede further dissolution.…”

A Geochemical and Geophysical Characterization of Sulfide Mine Ponds at the Iberian Pyrite Belt (Spain)

“…The mining industry in the province of Hue Iv a left 19 tailings dumps; 11 are in an abandoned state (IGME 1998) and represent an important contamination problem (Acero et al 2007;Alvarez-Valero et al 2009;Hudson-Edwards et al 1999;Perez-L6pez et al 2007;Simchez Espaii a et al 2005). Remediation has only been carr ied out in a few of the dumps, although they still show significant environmental problems (Martin-Crespo et al 2010).…”