Hydrogeochemistry at mining districts

Abstract

The Southern Urals exemplifies hydrogeochemical environments at mining districts. Information obtained by studying the geochemistry of nonferrous-metal industrial wastes (both mine and dump drainage) is important not only because these wastes are potential sources of base metals but also in the context of geoecological problems. The Southern Urals is one of Russia’s principal producers of Cu and Zn concentrates for metallurgical processing: the region produces 12–15% Cu and 49% Zn concentrates in the country and 35% Cu and 69% Zn concentrates in the Urals. The Yubileinoe, Podol’skoe, Sibai, Uchaly, Novy Uchaly, and Gai deposits are the largest in the Urals. The ores of these deposits contain certain components (Se, Te, Cd, Co, Ga, Ge, In, Be, etc.) that are environmental contaminants. The volume of mine and dump drainage in the Southern Urals amounts to 9 million m³/year, and its mineralization varies from 3.0 to 30–40 g/L, occasionally as high as 365 g/L, with a sulfate, chloride–sulfate calcic–magnesian, magnesian–sodic, and magnesian–calcic composition of the waters. The minor and trace elements of the regional waste waters whose concentrations exceed the regional background values are Cu, Zn (one to four orders of magnitude), As, Cd (one to three orders of magnitude), Li and Be (one to two orders of magnitude). All waste waters transfer various contaminants into environmental subsystems and most actively modify the composition of the groundwaters. At the same time, dump drainage is a potentially important secondary source of valuable mineral components.