Al Hyndman is a principal consultant with Magnus Limited.
In this introduction to the Oils Sands Industry presentations at the Tailings and Mine Waste Conference, Al Hyndman provides a succinct and insightful summary of the challenges in oils sands tailings management. A very useful Tailings 101.
He reviews how fluid fine tailings are formed in the mining and processing of oil sands, the history of tailings management and the types of deposits for capturing fine tailings, the characteristics of the clay that creates the fine tailings challenge.
The large equipment and large volumes of mined material Muddy water after 2-3 years of settling is called mature fine tailings (MFT). The resistance of the mature fine tailings to settling was a surprise to the first large oil sands mining operation at Fort McMurray. The response was to focus on safe dam design for tailings ponds since it was clear that treatment of MFT was going to take longer while alternate treatment methods were developed. Deep deposits of MFT makes consolidation behaviour critical elements of treatment. Upward drainage through the MFT deposits will be necessary. Regardless of the surface treatment to force consolidation (sand capping, freeze-thaw, etc), the hydraulic conductivity of the MFT is the most important factor in this consolidation behaviour (and the number of years to get MFT consolidated). So treatments that improve hydraulic conductivity of consolidated MFT are essential. Removal of residual bitumen is one factor to improve hydraulic conductivity. He describes some field demonstrations of flocculation processes. He describes how this research and field testing is being captured in COSIA's industry practice recommendations.
Al Hyndman's presentation was part of the Tailings and Mine Wastes Conference, Nov. 4-6, 2013, Banff Alberta organized by OSTRF and the Geotechnical Centre, University of Alberta.
