Effects of the flood of August 2002 on mine water of the Freiberg ore deposit

摘要

In the central part of the Freiberg sulfide ore deposit the major flood event of August 2002 caused the flushing and flooding of large parts of the Freiberg mine causing changes in water chemistry and hydraulics. The load of heavy metals, Al and As discharging via the mine's main adit into the Triebisch/Elbe river rose up to 2600 times the normal level in the first days. Three months later, only deposit related elements such as Cd, Zn, As, and Pb showed significantly higher concentrations compared to the pre-fload average. In the flooded mine workings of the Freiberg mine major changes in the hydraulic regime in connection with strongly increased contaminant concentrations could be observed. However, some 6 1/2 months after the flood event only Cdand As showed concentrations still above the average. The re-establishment of the former hydraulic regime in the flooded mine workings, together with a normalization of mine water chemistry, can be expected within several months to years.