Regular paper Biogenic catalysis in sulphide minerals ’ weathering processes and acid mine drainage genesis*

Bioleaching and biogenesis are the main outputs from a large group of environmental processes participat-ing in the natural material cycle, used in raw materials processing. Bio-oxidation reactions are the main basis for bioleaching procedures, often participating in paral-lel leaching processes. During the leaching processes of polycomponent sulphide substrates, the factor of process selection also plays an important role, being in direct relation to the electric properties and galvanic ef-fect occurring between the individual components of the leaching substrate. This work gives a summary of the results of a research focused on the possibilities of us-ing biotechnological procedures for treatment of Slovak sulphide ores. The object of the research is extraction of valuable metals, undesirable admixtures and degrada-tion of crystal lattice of sulphides for subsequent chemi-cal leaching processing of precious metals. The results of experiments on the existence of biogenic processes in situ on waste dumps from exploitation containing resid-ual sulphides are also presented. The processes result in acid mine drainage water generation. These waters are strongly mineralised (over 48 g/L) and of low pH; that is why they are very caustic. The arsenic content (2.558 mg/L) in outflowing waters from old mines is high and over the limits set by the law