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Video - Evaluating evaporation & under-drainage in dewatering tailings. Presentation by Mike O'Kane

Mike O'Kane is the President and CEO of O'Kane Consultants Inc.

Mike O'Kane makes the case that understanding tailings ponds and dewatering performance starts first with understanding and working the climate data for the region  that the tailings pond is located in. So what are the cubic metres of tailings that can be placed on the surface of the tailings pond during the different seasons of the year? There is no average year (particularly in Alberta where we have a cool continental (highly variable) climate) so we should be making management decisions on the probability and risk of what has happened over the long term climatic record. He suggests using a numerical model that incorporates large spatial and temporal variability. Use the climatic record of weather data to predict the probability of removing water.

As an example of the danger of average assumptions, he describes the process of cracking on evaporative drying of the tailing surface. So does cracking speed evaporation? Not during the day (in contrast to what we would assume).

He resets the tailing ponds management process by stressing the importance of assessing the probability of attaining an evaporation goal instead of targeting an average amount per year to attain.  Pan evaporation is not useful. Lab models do not incorporate the temporal and spatial elements at work in the field. The big driver is climate and its variability.  

Mike Kane's presentation was a part of the Tailings and Mine Waste conference that took place in Banff, Alberta on November 5, 2013.