Colloids from mine drainage waters and their role in Sb and As transport

The presence of colloids may be causing the water solution to be of variable composition and thus to quantify the role of colloids on water composition becomes a difficult task. Five abandoned Sb deposits in Slovakia (Pezinok, Poproc, Medzibrod, Dubrava, Cucma) and the recently active Beaverbrook Sb mine in Canada were chosen for this research. The Sb hydrothermal deposits in Slovakia are located in the Western Carpathians. The ore mineralization includes Au-bearing pyrite (FeS₂) and stibnite (Sb₂S₃) which are associated with abundant arsenopyrite (FeAsS). The mines used to be the most important Sb sources in Europe especially before and during 2nd World War, when former Czechoslovakia was the 6th biggest Sb producer in the world. All mining activities stopped by 1990s. Because the flotation technologies were not as developed at the time and no remediation was required, the mines left the legacy of contamination, mostly by Sb and As, and are currently abandoned. (authors)