No description available.

Commercial Magnafloc 1011and in-house synthesized Al-PAM were used as flocculants for model tailings, laboratory extraction tailings and tailings from paraffin froth treatment unit. The polymers were tested for their flocculation ability in settling and filtration. For model tailings, both polymers showed excellent ability to improve the settling and filtration performance. Magnafloc 1011 is found sensitive to overdosing, but Al-PAM is not sensitive to the dosage within the tested range. For the laboratory extraction tailings, both polymers showed excellent ability to enhance settling. Al-PAM performed very well as a filtration aid. The moisture of the cake obtained from tailings derived from a low fines ore was 6.6 1.2wt% and that from a high fines ore was 16.9 0.8wt%. However, Magnafloc 1011 was found not effective as a filtration aid. For the froth treatment tailings, Al-PAM improved the settling and filterability dramatically. Although the moisture of the cake obtained was 42.5wt%, no free water is seen visually in the cake. The solid cake is self-supportive and remains intact. This class of Al-PAM polymers can provide an alternative approach for oil sands tailings disposal that can potentially eliminate tailings ponds. / Chemical Engineering

No description available.

No description available.

Bitumen recovery by the water-based extraction process produces waste streams known as tailings. When discharged into the tailing ponds, the coarse solids in the tailings stream settle out quickly, while the fine solids accumulate over years of settling to a solids content of 30-35% by weight. The formed fluid fine solids sludge, known as mature fine tailings (MFT), traps 1-3% by weight hydrocarbons within its stable slurry structure. The remediation of these mature fine tailings is one of the major challenges facing the oil sands industry. This study was intended to investigate the recovery of residual hydrocarbons in the MFT by froth flotation process. Using a laboratory Denver flotation cell operated in a batch mode, the effect of MFT dilution ratio by process water or tap water, the flotation hydrodynamics and aeration rate on hydrocarbon recovery kinetics was studied. It was found that at 1:2 dilution by weight of the MFT with process water, increasing aeration rate has a more favourable effect on recovering more than 85% of the hydrocarbons from the MFT. The hydrocarbon-rich froth produced was treated by naphtha and was found to produce a hydrocarbon product similar to diluted bitumen obtained in bitumen extraction process, suitable for upgrading. Similar approach was applied to the hydrocarbon-rich tailings from the Tailings Solvent Recovery Unit of paraffinic froth treatment. Satisfactory recovery of hydrocarbons from the MFT was obtained using a flotation column operated in a continuous mode, confirmed the results obtained from the batch tests. The tailings produced from the continuous flotation experiments were treated with polymer flocculants such as Magnafloc-1011 and Al-PAM to study the effect of hydrocarbon recovery on the remediation of the MFT. The results from initial tests showed that both flocculants were not as effective on flocculating MFT solids following the recovery of hydrocarbons by froth flotation. / in Chemical Engineering