A MINERALOGICAL ASSESSMENT OF TAILING IMPOUNDMENTS NEAR MARKUSOVCE AND SLOVINKY (SLOVAKIA)

11th International Multidisciplinary Scientific GeoConference SGEM2011, www.sgem.org, SGEM2011 Conference Proceedings/ ISSN 1314-2704, June 20-25, 2011, Vol. 3, 167-170 pp

ABSTRACT

A detailed study of the weathering products is an important step toward the
comprehension of the complex processes operating in the environment of mine tailings.
The identification of the carriers of the pollutants is a prerequisite for the assessment of
the contamination risk and a remediation or immobilization strategy. In this study, we
describe sulfide oxidation processes and the resulting chemical composition of the
weathering products within 2 tailing impoundments rich in Fe, Ca, Si, Ba and Al.
Content of potentially toxic elements (such as As, Sb, Zn, Pb and Hg) in tailings is in
hundreds of mg/kg. Acidity produced by sulfide decomposition is neutralized by
abundant carbonates and the pH values are mostly near-neutral or slightly alkaline.
The most common mineral in heavy fraction of tailing material is barite, siderite and
hematite are also common. Pyrite is the most frequent sulfide in the tailings,
arsenopyrite, tetrahedrite and chalcopyrite are also present. Cinnabar and copper occur
rarely in the samples.

In the oxidation zone of the tailings primary minerals are being oxidized. The newly
formed secondary minerals have variable chemical composition and point out that the
observed elements (As, Sb, Zn, Pb, Hg, Ca, Fe) are mobile and could be transport
within the top layers of the tailings.

Keywords: weathering products, tailings, mineralogy