| Abstract | The hot water process used by Suncor and Synacrude to extract bitumen from the Athabasca Oil Sands produces large volumes of tailings slurry. The fine grained sludge component of this waste is the most troublesome because of its stability and poor compaction potential. The sludge apparently owes its stability substantially to a complex interaction between organic coated amorphous particles, clays and bitumen. In this study we have investigated the nature of both the minerals and the associated organic matter present in a thickened, aqueous tailings sludge sample, from the Synacrude Canada Limited plant. An oil phase agglomeration technique was used to remove free bitumen and associated oil wettable solids from the sludge. On standing, the treated sludge, unlike a comparable blank, separated into settling and non-settling fractions. The solids from these fractions were analyzed by; X-ray diffractometry, Inductively Coupled Plasma Atomic Emission Spectrometry, Solid State MAS ²⁹Si and ²⁷Al NMR spectroscopy in an attempt to characterize the inorganic minerals present. The oil phase solids showed considerable enrichment in heavy metals compared to the other solids. The findings of this study could be helpful in providing some insight into the nature of tailings pond sludge, a problem which poses the most imminent environmental contraint to future use of the "hot water" process. |
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