When Canadian Natural assessed the viability of non-segregating tailings (NST) as their primary fine tailings management strategy for complying with Alberta’s oil sands tailings reclamation requirements, they turned to Barr and the Dutch firm Deltares to plan and implement a NST deposition study. Barr and Deltares developed a bench- and pilot-scale test program in close coordination with Canadian Natural to evaluate the degree to which NST slurries segregate into their component parts during deposition using different mixtures and deposition methods, with the goal of identifying which combination of slurry composition and deposition method produces the least segregated deposit. Barr and Deltares also designed the testing apparatus, which included a tremie-diffuser deposition system and a 25-meter-long instrumented flume, and supervised equipment commissioning and operation.
The study was completed in two parts: evaluation of sub-aqueous and sub-aerial NST deposition (Part 1) and evaluation of three subaerial NST deposition methods and evaluation of deposits flowing over a long beach (Part 2). Barr supervised preparation of the NST slurries for the test program from mine-supplied materials by thickening fine tailings and adding sand to produce mixtures with target compositions and physical properties. Data collected from instruments and physical samples during and after the tests were compiled and analyzed, including development of a model to predict the segregation behavior of NST slurries based on composition and flow dynamics. A comprehensive report was then completed, and the model developed during this project was presented at the Third International Oil Sands Tailings Conference in 2012.
Vice President Senior Civil Engineer
Vice President Senior Geologist