A by-product of bitumen extraction, mature fine tailings (MFT) are a mixture of fine solid clay, mineral particles and suspended hydrocarbons. MFT stable dispersion can last for decades and it is estimated that 800 million m3 are formed per year in Alberta. As of July 2012, the Energy Resource Conservation Board Directive 74 mandates that 50% of solids in the tailings must be removed from the waste stream. Oil sands operators are currently facing severe challenges to meet these requirements both from a technical and economic standpoint. Additionally, the most common industrial flocculants are costly, lack biodegradability, and are environmentally toxic.
Researchers at the University of Alberta have developed a proprietary technique to coagulate and flocculate (aggregate) waste water colloidal suspensions, including mature fine tailings, using specified risk materials (agricultural waste). Specified risk materials are a waste stream from the animal rendering industry available at minimal cost and in enormous quantities. The turbidity of the water processed by this technology is orders of magnitude lower than water processed with gelatin, which is an order of magnitude less than water processed with anionic polyacrylamide (PAM). With this technology, significant reductions in cost and released water turbidity can be achieved.
- Released water is 80 times less turbid than gelatin flocculant
- Low input costs and widespread availability Figure 1. Flocculation of tailing pond samples
- Renewable, biodegradable, and environmentally friendly from the Athabasca Region: turbidities of released water are 858 and 10.8 for gelatin and SRM, respectively.
Technology Management Group
TEC Edmonton – University of Alberta