The article presents the original results of the investigation of sulfide-bearing mine tailings dumps (Ursk, Western Siberia, Russia), the adjacent territory, and acid mine drainage flows. The novelty of this study is related to integration of geophysical and geochemical data. The geoelectrical structure of the dump and the drainage valley was determined using the electrical resistivity tomography (ERT) method. Magnetic anomalies above the surface of the site were identified using ground magnetic surveys. The orthophotomap and a digital elevation model were obtained on the basis of aerial photography from an unmanned aircraft. The model of thermal imaging allows us to identify a number of temperature anomalies in the upper part of the dump slope and filtration zone in the drainage valley, caused by exothermic reactions. The digital relief model was constructed comprising three zones: (1) oxidation, (2) leaching, and (3) mixing and dilution. The oxidation zone is marked by low electrical resistivity (1–10 Ω·m), low pH values of the drainage waters (pH 3.61), low values of the modulus of the magnetic induction vector, and heating by +5 °C compared to the solid dump material that is not actively exposed to water. The oxidative conditions and low pH values favor the dilution of the Fe2+ compounds in the drainage solutions, which also contain Cu (3000 μg/L), Pb (1200 μg/L), As (1300 μg/L), and Hg (34 μg/L). The zone of the primary geochemical barrier is formed within the first 400 m, where the major proportion of dissolved elements if deposited. The second iron–aluminum sorption geochemical barrier is formed at a distance of 1000 m at the mixing zone with the Ur River. The stable geochemistry of surface waters, formed due to the inflow of drainage waters into the Ur River and further into the reservoir, persists at a distance of up to 7.7 km from the dump.
29 September 2017 in Toxicological & Environmental Chemistry
Sulfide-containing mill wastes of the Komsomolsk ore processing plant situated in the Kemerovo region (Russia) were examined in 2013–2015. Multipurpose studies of the mine tailings determined the composition of waste, pore water, mine drainages, and affected groundwater. Electrical resistivity tomography was used to trace the geoelectric zoning of the waste samples. Layers with low resistivity indicated areas with pore spaces filled with highly mineralized solutions with Fe, Cu, Zn, Cd, As, and Sb at total concentrations of up to 50 g/L. Anomalous zones can be specified as ‘geochemical barriers’ – specific layers where the mobility of the elements is reduced due to pH conditions, redox potential, and Fe(III) hydroxide precipitation. The zones of increased conductivity in oxidized mine tailings indicated local areas with high acid production potential and coexisting acidic pore solution. In non-oxidized tailings, high conductivity of the mineral skeleton was observed. There was a migration of drainage outside the tailings, its direction monitored by geophysical data. Chemical analysis confirmed that the concentrations of As in groundwater samples were higher than the maximum permissible concentration.
Integrated study of the Dyukov Log dump of sulfide-containing mine tailings of the Salair ore-processing plant (SOP) was performed using geophysical and geochemical methods. Geochemical data and results of electromagnetic-frequency sounding and electrical-resistivity tomography were used to establish the geoelectric zoning of the tailings and the relations between the electrical parameters of the environment and the chemical composition of the tailings and pore water. The proposed approach will make it possible in the future to evaluate the amount of tailings. The drainage water flow paths were determined, and the penetration of highly saline industrial solutions into groundwater was proved.
1 March 2018 in Journal of Geochemical Exploration