GEOCHEMICAL CHARACTERISTICS OF ACID MINE DRAINAGE AT THE SMOLNÍK DEPOSIT (SLOVAK REPUBLIC)

The attenuation of mining activity in the Slovak Republic that started in 1989 led to the extensive closing of deposits using wet conservation, i.e. flooding. Negative effects of AMD can be observed mainly in the localities where sulphide ores and sulphide-containing raw materials used to be mined. The Smolník deposit is one of the historically best-known and richest Cu-Fe ore deposits in the Slovak Republic. The discharging mine waters of pH 3.7 containing high concentrations of sulphates, Fe, Mn, Cu, Zn, Al have a negative effect, mainly on the Smolník stream. In order to propose an effective and economically acceptable remediation method to prevent the negative influence of AMD on this locality, a regular monitoring of AMD quality was carried out. The article presents the results of monitoring carried out in 1986 – 2006. The geochemical modeling of AMD quality was also realized. It was aimed at the simulation of AMD evolution during its gradual ascent from the depth of 200 m to the surface when reacting with pyrite. On the basis of modelling results it is assumed that the amorphous ferric hydroxide, jarosite and pyrolusite will gradually precipitate.