Thickening and disposal of oil sand tailings

Oil sand tailings are being disposed of in large ponds in which mature fine tailings (MFT), a stable suspension of fine particles in water, forms after many years of settling. Long-term storage of large volumes of MFT is costly to maintain and poses an environmental liability. CANMET Energy Technology Center-Devon has worked closely with oil sand companies to eliminate MFT generation by applying paste technology to oil sand tailings. In this process, the fine tailings are flocculated to produce a thickened material that has the potential to consolidate to a dry landscape. In addition, warm water is recovered in the process for reuse in the extraction process. This paper presents some results of an extensive technical program involving benchscale tests for flocculant selections and continuous thickener pilot tests.