Mining, the environment and the treatment of mine effluents

The environmental impact of mining on the ecosystem, including land, water and air, has become an unavoidable reality. Guidelines and regulations have been promulgated to protect the environment throughout mining activities f rom start-up to site decommissioning. In particular, the occurrence of acid mine drainage (AMD), due to oxidation of sulfide mineral wastes, has becom e the major area of concern to many mining industries during operations and after site decommissioning. AMD is characterized by high acidity and a hig h concentration of sulfates and dissolved metals. If it cannot be prevented or controlled, it must be treated to eliminate acidity, and reduce heavy m etals and suspended solids before release to the environment. This paper di scusses conventional and new methods used for the treatment of mine effluen ts, in particular the treatment of AMD.