Trace element geochemistry of self-burning and weathering of a mineralized coal waste dump: The Novátor mine, Czech Republic

The leaching potential of trace elements present in the waste samples was determined using batch leaching tests. The concentrations of sulfates, F, Se, Cd, Hg and Pb in some samples of water leachates from unburnt as well as burnt materials exceed the leaching limit values for inert wastes according to the EU legislation. The concentration of U in water leachates from burnt samples reaches max. 0.4 mg·kg− 1. Coal wastes of the Novátor mine were exposed to leaching and weathering over almost 50 years. Within this period, the soluble authigenic minerals that originated due to self-burning were already dissolved or transformed to less soluble species. However, the results of leaching tests indicate that the dumped material, both unburnt and burnt, may still represent a potential source of contamination for local streams.