H.K. Mittal is a Principal at H.K. Mittal and Associates, in Saskatoon, Saskatchewan. Mittal reviews the experience of uranium mining companies in treating tailings and tailing ponds to provide some suggestions for oil sands companies in meeting the objectives of the Alberta Energy Regulator's (formerly the ERCB) Directive 074. According to Directive 074, tailings in Designated Disposal Areas (DDA) are to have an undrained strength of 5kPa within one year. Five years after tailings deposition, the trafficability of 10 kPa must be achieved and the tailings must be ready for reclamation.
Mittal explains that uranium mines have experience in the both of the above requirements of the ERCD Directive 074, and shares his insight on the matter. He clarified that uranium mines have difficulty reaching the second part of the third objective, that there be a trafficable surface of Su of 10 kPa.
Mittal then outlines what was used at the Rabbit Lake Uranium Mine in northern Saskatchewan to manage filtered tailings, and thickened tailings slurry. He includes information about frost problems, and their solution involving subaqueous deposition of the tailings slurry. Timely consolidation of the tailings is attributable to its hydraulic conductivity of 10(-7) to 10(-8) m/s, which is useful because oil sands tailings have similar hydraulic conductivites. He also discusses the issue of future settling after covering the tailings.
H.K. Mittal's presentation was part of the Tailings and Mine Waste conference in Banff, Alberta, from Nov. 3-6, 2013.
