Depositional and geotechnical characteristics of paste produced from oil sands tailings

Syncrude Canada is evaluating the potential of paste technology as an alternative method of fine tailings disposal. Fine tailings is pumped to a thickener vessel and flocculant added to promote rapid settling of the solids. The supernatant water released is returned to the bitumen separation process immediately and a settling basin is no longer required. The thickener underflow (paste) is pumped to a disposal site where a ‘solid’ tailings deposit is formed. Depositional and geotechnical testing has been conducted on the paste produced from small scale batch and continuous thickener (2 m long x 300 mm diameter) tests. The tests consisted of depositing the paste into a 300 mm wide and 9 m long flume and monitoring the behaviour. Samples were taken for strength (triaxial compression) and consolidation tests. The results are presented in the paper.