Wells, PS 2010, 'Tailings philosophies — to segregate or not to segregate', in R Jewell & AB Fourie (eds), Proceedings of the Thirteenth International Seminar on Paste and Thickened Tailings
, Australian Centre for Geomechanics, Perth, pp. 451-458.
Facilities in the oil sands of north-eastern Alberta have developed and operated several generations of
technologies for the treatment of tailings resulting from bitumen extraction processes. These processes
produce tailings streams that undergo segregation when discharged into water filled ponds. Coarse sand
settles to the pond bottom as long beaches, while a percentage of the silts and clays remain suspended within
the water column and are viewed as a major contributor to the oil sand challenges of water loss and storage
volume increases. Traditional methods of dealing with these challenges have involved mainly recombining
all the original solids (sands, silts and clays) into a non-segregating mixture. These methods assume that
mixing the ‘good’ coarse material with the partially settled ‘bad’ suspended silts and clays can result in a
well behaved, reclaimable deposit. This may not be the case, and it can be suggested that the pursuit of this
goal may have created unrealistic objectives for tailings treatment, and served to slow development.
An alternative treatment philosophy is to identify the materials which are at the root of the existing tailings
challenges and develop systems to isolate and treat those materials. Several technologies exist for this, and
direct comparisons between these two philosophies involving the treatment material balances, process water
balance, and material handling requirements can be made. Such comparisons have identified opportunities
for improvements in the technology development focus by the various research and operational
organisations and are beginning to produce alternative technologies that are more robust and effective.
Donahue, R., Jeeravipoolvarn, S., Scott, D. and Ozum, B. (2008) Properties of Non-segregating Tailings Produced from
the Aurora Oil Sands Mine Tailings, in Proceedings First International Oil Sands Tailings Conference,
OSTRF/CONRAD, Edmonton, AB, pp. 143–152.
Fine Tailings Fundamentals Consortium (1995) Vol I. Fundamental Properties of Fine Tails in: Advanced in Oil Sands
Tailings Research, Alberta Department of Energy, Oil Sands and Research Division, pp. 45–54.
Sobkowicz, J. and Morgenstern, N.R. (2009) A geotechnical perspective on oil sands tailings, in Proceedings Tailings
and Mine Waste ’09, U of A Geotechnical Centre, Edmonton, AB, pp. xvii–xli.
Wells, P.S. (2004) Advances in CT Deposition at Suncor Energy, Oilsands, CONRAD Tailings Seminar, Edmonton,
Wells, P.S. and Riley, D.A. (2007) MFT Drying – Case Study in the Use of Rheological Modification and Dewatering
of Fine Tailings Through Thin Lift Deposition in the Oil Sands of Alberta, in Proceedings Tenth International
Seminar on Paste and Thickened Tailings, A.B. Fourie and R.J. Jewell (eds), Australian Centre for
Geomechanics, Perth, Australia, pp. 271–284.