Aluminium solubility in acid waters of the abandoned open pyrite mine at Wieściszowice (Rudawy Janowickie Mts., West Sudetes)

Abstract

The study of chemical composition of waters in the abandoned open pyrite mine at Wieściszowice (the Rudawy Janowickie Mts., the W Sudetes, SW Poland) has been carried out with the aim of detemining the conditions of mobi1ization and solubility of aluminium. Both the ion activities and the saturation of water samples with respect to mineral phases have been calculated using the WATEQ4F computer program. Sulphate waters have been found in the mine area. with total dissolved solids TDS) in the range of 1500-5800 mg/l, low pH (2.50-2.98) and high concentration of aluminium, from 1.18 • 10^-3 to 6.52 . 10^{-3 M (31.9-176 mgl/Al). The analysis of ion activities and chemical equilibrium of waters from the mine area indicates that aluminium solubility is controlled by the basic aluminium sulphate, AlOHSO}₄. On the other hand, clay minerals (most likely kaolinite) control Al content in waters occurring in the outcrop of pyrite-bearing schists outside the mine area.