IDENTIFICATION OF MERCURY IN SASKATCHEWAN CORE SAMPLES

Bioaccumulation of mercury is a rising environmental concern and is partly attributed to the mercury emitted from power plant flue gas. Regulation of mercury emissions is being proposed for legislation in both Canada and the United States. These legislative proposals create a need for reducing mercury emissions. The reduction of mercury emissions from the combustion of Saskatchewan lignite coal is challenging due to the high fraction of elemental mercury. One possible strategy for reducing mercury emissions is to selectively mine low mercury coal. SaskPower has initiated studies of 10 core samples from four areas with different geologic histories. Three areas were located near Boundary Dam Power Station in Estevan, Saskatchewan and one area was located near Poplar River Power Station in Coronach, Saskatchewan. Loss on ignition (LOI), mercury, and sulphur contents were determined to characterize the relationship between coal bed depth and mercury content. Further studies on the core samples resulted in a correlation between elevated mercury content and partings in the coal bed. Such information is valuable as a coal bed parting, with elevated mercury content, may be avoided, sent to a facility with mercury control technology or removed by strategies, such as air jigging, prior to combustion. With further research and development, selective mining, in addition to the advancement of mercury control technologies, provides an effective means of reducing the amount of mercury emitted from power plants in Saskatchewan.