Evaluation of mine site reclamation performance using physical models: Case of Ity mine (Ivory coast)

Abstract

The exploitation of the Ity gold mine in Ivory Coast will generate tailings that can be considered as potential generators of acid mine drainage (AMD). Various materials such as marble and clay are available around the mine site that could be used as components of an engineered cover for the reclamation of the reactive tailings impoundment. However, it is important to assess the properties of these potential cover materials and test different reclamation scenarios in the laboratory to select the best scenario for mine site reclamation. For this purpose, physical modeling was performed using experimental instrumented column tests simulating covers with capillary barrier effects (CCBEs) and monolayer covers. The columns were instrumented with sensors for measurement of volumetric water content (VWC) and suction. Leaching tests were performed over many cycles and physical and chemical analyses were carried out on the leachates. The observed hydrogeological behavior shows that either a CCBE or a monolayer cover with clayey silt materials can be used for the Ity mine site reclamation. However, hydrochemical results allow confirming that the monolayer cover made with clayey silt material can be considered as the best scenario for the Ity mine site reclamation.