Eliminating Acid Rock Drainage (ARD) at Mine Doyon - Sustained Operations allow for New Possibilities

摘要

Mine Doyon, located in the Abitibi Region of Quebec, has been in operation since 1978. First operated as an open pit gold mine, the issue of ARD was not identified prior to operations and resulted in the construction of roads, dams, and waste rock piles with acid generating materials. The problem was intensely studied through the MEND program primarily by the Groupe de Recherche en Environnement et Geo-Ingenierie (GREGI), of Laval University from 1991 to 1994. As the operation moved to underground ore extraction, the open pit became available for disposal of materials and allowed commencing of the rehabilitation process. Operations at Doyon ended in 2010, but with the discovery of the nearby Westwood deposit, new ideas and opportunities are being explored to rehabilitate the Doyon waste disposal areas to reduce the risk of ARD and provide for the next years to further study rehabilitation options. As mining activities will continue, the bulk of the former waste disposal sites is not required to be restored now allowing for both new ideas and cost-effective implementation.This paper will discuss the use of the open pit for managing ARD wastes, de-pyritized tailings covers and the use of treatment plant sludge to evolve an improved closure strategy for Doyon Mine.