Department of Geochemistry and Economic Geology, Faculty of Geology and Geoenvironment, National & Kapodistrian University of Athens, Panepistimiopolis, Ano Ilissia, 15784, Athens, Greece.
Laboratory of Metallurgy, School of Mining and Metallurgical Engineering, National Technical University of Athens, Zografou Campus, 15780, Athens, Greece.
Bull Environ Contam Toxicol. 2021 Mar;106(3):465-474. doi: 10.1007/s00128-021-03122-w. Epub 2021 Feb 15.
The disposal of lignite spoil and tailings poses a major environmental problem in lignite mining sites which is associated with the oxidation of sulfide minerals contained in the primary ore. This process renders acidic effluents. Lignite mining in the Oropos Neogene basin, North Attica, Greece operated since the last century and ceased in the late 1960s. Piles of complex waste material are dispersed close to the mining sites. The high sulfur content and low Net Neutralization Potential, i.e. values < - 20 CaCO kg/t in most analyzed waste samples, indicate that the waste is prone to acid generation. The leachates (EN12457) from the lignite spoils showed high concentrations in Ni and Zn exceeding the EU regulatory limits for the non-hazardous wastes. GIS-based geochemical maps of the topsoil showed enrichment in Ni (Cr, V) associated with the regional geogenic enrichment but also local accumulation around the hot spot sites of lignite spoil heaps.
褐煤废渣和尾矿的处理是褐煤开采过程中面临的主要环境问题，这与矿石中含有的硫化物矿物的氧化有关。这个过程会产生酸性废水。希腊北阿提卡奥罗波斯新第三纪盆地的褐煤开采从上世纪开始，一直持续到 20 世纪 60 年代末。成堆的复杂废料被分散在矿区附近。大多数分析的废物样本中的高硫含量和低净中和潜力，即值 < -20 CaCO kg/t，表明废物容易产生酸。从褐煤废料中浸出的（EN12457）显示出高浓度的 Ni 和 Zn，超过了欧盟对非危险废物的监管限制。基于 GIS 的表土地球化学图显示 Ni（Cr、V）的富集与区域地球化学的富集有关，但也与褐煤废料堆热点地区周围的局部积累有关。
