Jonathan Spence is the Senior Associate in the R & D Tailings Technology Team for Syncrude Canada Limited.
Jonathan Spence covers four topics: he discusses the procedure Syncrude uses to process their fluid fine tailings (FFT), explains their centrifuge development program, their 2011 centrifuge prototype, and their plan forward into commercialization.
Their procedure for their FFT involves adding gypsum and flocculent and processing the amended FFT in a centrifuge, which separates the liquid from the solids. The liquid goes to a settling pond and the solid matter, "cake", is deposited into a pit after being dewatered by fifty percent.
Their centrifuge development program began with a lab scale proof of concept in 2005. In 2010, centrifuge cake transport options were tested. In 2011, Syncrude evaluated the performance of two commercial decanter centrifuges of 1 metre and 1.4 metre in diameter, and optimized gypsum and flocculent mixing, as well as achieved targets of over 95% solids in cake.
In their centrifuge development program, they measured centrifuge throughput and bowl speed with gypsum and without. They measured vendor predictions against centrifuge "steep beach" and "shallow beach" results. Once they measured the efficiency and effectiveness of the centrifuges, they were able to reduce their centrifuge requirements by 40%. That eliminated one of the centrifuge buildings originally planned and saved construction costs.
Jonathan Spence explains the 2011 centrifuge prototype exceeded vendor throughput predictions, and the optimum centrifuge operating parameters were defined. In 2015, the full scale FFT centrifuge plant will process fluid fine tailings from the Mildred Lake Settling Basin. The centrifuge technology developed will provide COSIA Tailings EPA members with additional information in order to deal with FFT.
Jonathan Spence's presentation was part of the Tailings and Mining Wastes conference in November 2013, in Banff, Alberta.
