Geochemical behaviour of some heavy metals of the Grot flotation tailing, Southeast Serbia

Grot tailing dump has the highest altitude of all tailing dumps in the Republic of Serbia. About 5.5 million tons of hydrocycloned sand was deposited in the tailing dump. This material was formed by flotation processing of ore from the Blagodat ore field. Vegetation was not developed in any part of the tailing. Minerals determined by X-ray diffraction analyses of representative samples form the tailing are quartz, clay minerals, calcite, feldspars, hematite, siderite, pyrite, sphalerite, galena and chalcopyrite. No regularities were noticed in their quantitative distribution. Statistical analysis of chemical fluctuations of lead, zinc, copper, arsenic and manganese concentrations showed that those with the highest concentrations are usually found on the central plateau. Lead displays the largest concentration range in the whole tailing. Maximal concentrations are found on the central and minimal in the south-western plateau. Zinc concentrations are up to 5,000 mg/kg, except in the central plateau where they reach extreme several times higher values. Copper concentrations are increased in the central plateau. In other parts of the tailing, concentrations are uniform and several times lower. Arsenic concentrations are mostly uniform, with the exception of extreme values in the north-western parts of the central plateau. Manganese shows uniform concentrations, somewhat increased on the south-eastern plateau. Chemical heterogeneity of the tailing material was influenced by the chronological discontinuity of the deposition and resedimentation. Resedimentation was the main cause of the fluctuation in the concentrations of the most mentioned heavy metals.