Simon Yuan is a Senior Engineering Associate with Syncrude Canada in Edmonton, Alberta. He talks briefly about the differences between diluted FFT flocculation and high density FFT flocculation, and explains that the objectives of the project are to develop the success criteria for high density FFT flocculation, and verify their applications to high density FFT flocculation and centrifugation. He discusses the experimental materials, flocculants, and lab test facilities, and focuses on the four success criteria for high density FFT flocculation and their applications.
Yuan explains that one of the most effective ways to attain fine clay flocculation and polymer dosage reduction is to dilute the thickener feed, but this was not economically feasible for FFT centrifugation, thin-lift and thick lift.
The materials for the test were "Syncrude FFT with about 35% solids and 95-100% -44 um fines. The flocculants tested were Polymer A (linear) and Polymer B (branched)". The lab test facilities included: a motor, a torque sensor, a 315 mm mixing tank, a flocculent injection pump, an impeller speed control box, and an on-line data acquisition system.
The test included filling 18 kg of slurry into the 315 mm tank and mix at the determined speed, then pump in the flocculent solution, and take samples at different times within the 0 to 5 minute post-flocculent injection, and measure Yield Stress, CST and Centrifuge Index, as well as take pictures of flocculent structures of the samples immediately after each test.
Yuan came to several conclusions from the test he implemented. He created four criteria to determine the performances of high density FFT mixing and flocculation. The applications of these criteria were validated, and the on-line monitored data gave a better understanding of the high density FFT mixing and flocculation mechanisms. The four mixing stages will help with engineering design and operation of the high density FFT mixing system.
He explains, the "geometric parameters obtained with the lab 315 mm tank were successfully used to scale up the pilot dynamic mixing tanks for the 2010 FFT centrifuge field tests", which made the engineering foundations for a commercial dynamic mixing tank scale-up.
Simon Yuan's presentation was part of the Tailings and Mine Waste conference in Banff, Alberta, November, 2013.