ABSTRACT
ABSTRACT: Mine tailing properties significantly differ from other mine waste (e.g. waste rock and heap leach material) such that cover system design criteria for cover success and post-closure monitoring should require different approaches. Tailings can generally be classified into three material types corresponding to location within the impoundment, with each material type possessing distinct physical and hydraulic properties. Finding from tailings reclamation research and performance monitoring at five tailings facilities in the southwestern United States indicate that: (1) alternative cover system designs based on location within the impoundment can maximize performance (and reduce costs), (2) tailings underlying shallow evapotranspirative cover systems play a significant role in reducing net percolation, whether they are non-acid or acid, and (3) depending on the cover material properties and climate, monolayer covers over acid tailings may show limited acidification and salinization. Consequently, tailings cover system design should consider potential interactions between the tailings, cover material and vegetation.
