Abstract: Environmentally compatible Waste Management schemes employed by the European extractive industry for the development of new projects, and applied in operating sulphide mines, are presented in this study. Standard methodologies used to assess the geotechnical and geochemical properties of the solid wastes stemming from mining and processing of sulphidic metal ores are firstly given. Based on waste properties, the measures applied to ensure the environmentally safe recycling and disposal of sulphidic wastes are summarised. Emphasis is given on the novel techniques developed to effectively prevent and mitigate the acid drainage phenomenon from sulphidic mine wastes and tailings. Remediation measures taken to minimise the impact from waste disposal sites in the post-closure period are described.

Abstract: An acid mine drainage in abandoned Horobetsu mine in Hokkaido, Japan, contains arsenic and iron ions; total arsenic ca.10ppm, As(III) ca. 8.5ppm, total iron 379ppm, ferrous iron 266ppm, pH1.8. Arsenic occurs mostly as arsenite (As (III)) or arsenate (As (V)) in natural water. As(III) is more difficult to be remove than As(V), and it is necessary to oxidize As(III) to As(V) for effective removal. 5mL of the mine drainage or its filtrate through the membrane filter (pore size 0.45 mu m) were added to arsenite solutions (pH1.8) with the concentration of 5ppm. After the incubation of 30 days, As(III) was oxidized completely with the addition of the mine drainage while the oxidation did not occur with the addition of filtrate, indicating the microbial oxidation of As(III). In this paper, we have investigated the microbial oxidation of As(III) in acid water below pH2.0.