Selected hazards to quality of groundwater resulting from the reclamation of an open pit with waste rocks - a case study of a backfill sand mine

Abstract

The use of rock wastes after mining and processing of hard coal for reclamation of opencast workings is a common form of restoring utility functions to these areas. The origin of these wastes, their properties, petrographic and mineral composition as well as the method and time of depositing in the excavation directly affect the emissions to the soil and water environment of pollutants, which may affect the quality of groundwater in the area of the open pit and significantly affect the possibility of their economic use. On the example of CTL Maczki-Bór S.A. backfill sand mine an analysis of the leachability of selected components from post-mining wastes, differentiated in terms of their deposition time and exposure to external factors, was performed. The article presents the results of analyzes of the content of components (elements and/or ions) in the form of their concentrations in the aqueous solution and per unit of dry mass of the tested wastes. The correlation was assessed between the concentration values of selected components, obtained in laboratory tests in pore extracts, and those observed in-situ in the drainage well made in the waste dump