Environmental impact from supergene alteration and exploitation of a high sulphidation epithermal type mineralisation (Kirki, NE Greece)

Abstract

The base-metal sector of the high-sulphidation epithermal deposit of Kirki (St Philippe) was occasionally mined during the period 1973–1998, without strict environmental management. The mineralisation shows a significant content of polluting elements. Mineralogical investigations indicate a very low degree of sulphide alteration. Sphalerite and galena concentrates were produced by conventional flotation techniques. Mine excavation wastes and flotation tailings were dumped and exposed to weathering. Waters draining downstream of the mine waste dump are near neutral. Acid mine waters forming a pit lake are highly polluted. Evapoconcentration of the pit lake waters leads to the generation of a toxic mineral precipitate on the open pit floor, comprising soluble secondary salts. The paper concludes with a consideration of the remedial measures required.