2013 Colloquium of the Canadian Geotechnical Society: Geotechnical and geoenvironmental behaviour of high-density tailings

The breaching of containment of conventionally deposited mine tailings impoundments, and the consequent release of tailings flows with long run-outs, unfortunately remains not uncommon and often has devastating ecological and economic consequences, occasionally including the loss of human life. Rather than the breaching of containment itself, which can result from a number of causes (poor control of the phreatic surface, unrecognized dam foundation issues), the contributing factor to the severe consequences of dam breach is the very low density and strength and / or susceptibility of the tailings to liquefy or soften under loading, combined with the driving weight of the ponded water, which allows for significant run-outs (in some cases 10â s of kilometres) to occur. Hence the motivation for alternative technologies that dewater tailings before deposition to the point where reliance on containment is minimized or eliminated. In this paper, these technologies are referred to as High Density tailings, which includes any technology that at least produces non-segregating tailings that will form a sloped stack when deposited, including thickened, paste, and filtered tailings. The paper explores a number of issues related to high density tailings, including shear behaviour, dewatering behaviour, acid generation, and surface deposition rheology. The paper concludes with some discussion on what are the limitations on this technology holding back its wider adoption, and how these limitations might be overcome.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author