Use of red mud to rehabilitate AMD-generating tailings - Dunraine site case history
Symposium Rouyn-Noranda 2002
Denis Isabel, Martine Paradis, Serge Vézina, Clément Brisson,
The old Duraine Mine tailings pond contains acid mine drainage generating tailings. The concept proposed to rehabilitate the site is to use the high alkaline potential of red mud from aluminium smelters to neutralize mine tailings. By applying a certain quantity of red mud to the surface of the pond, neutralization of the acidity is activated. Moreover, the alkalis contained in the red mud will cause the precipitation of stable minerals (sulphates such as jarosite). This precipitation of minerals will form an indurated layer, thus making oxygen and water circulation difficult. Even though this concept has been verified in the laboratory, they still are hypotheses that must be verified in actual working conditions.
The main questions arising from the use of red mud, apart from the geochemical concept, is the technical and economic context. Indeed, transporting a significant amount of wet, clayey material represents quite an economic challenge. Besides this challenge, handling and spreading this product onto tailings ponds comprised of fine saturated material also represents a significant challenge. This article presents the findings of a technical and economic study on the transportation, handling and spreading of red mud on the tailings ponds located in the Abitibi.