Mine Site Reclamation Challenge through Some Examples in Québec (Canada)

Abstract: The mining industry generates large amounts of solid and liquid waste. These wastes have the potential to adversely impact the environment if not properly managed. Special attention is required when the wastes contain sulfide minerals. The oxidation of sulfides minerals by atmospheric oxygen generates contaminant in the drainage water. This phenomenon is called acid mine drainage (AMD) when the effluents are acidic. In these situations, actions must be taken at the mine site to prevent environmental impacts caused by AMD. For that, reclamation of mine site constitutes the most important challenges for the mining industry and different techniques were developed to control the production of AMD. These techniques are used to eliminate, or to reduce to very low levels, the water flow (hydraulic barrier) and / or oxygen flux (oxygen barrier) to reactive tailings. Under humid climate conditions, the most appropriate techniques to control oxygen flux are: i) cover with capillary barrier effects (CCBE), and ii) monolayer cover with an elevated water table. These techniques were used for mine site reclamation in Abitibi-Témiscamingue (Québec, Canada). The emphasis will be on their characteristics, configuration and performance.