PIXE APPLICATION TO THE STUDY OF TRACE-ELEMENT BEHAVIOR IN COAL COMBUSTION CYCLE

The determination of the elemental composition of parent coal and of the different combustion products is important in giving an insight into the partitioning of major, minor and trace elements upon combustion and abatement by control devices in power plants. Besides the relevance of these data from the environmental point of view, the characterization of the pathways of the different elements through the combustion cycle, including combustion itself and fly ash abatement, is essential for the understanding, quantification and improvement of the fly ash precipitation mechanisms. In this work PIXE and PIGE techniques have been applied to the characterization of South African coal and its fly ash collected at the inlet and outlet of the electrostatic precipitators of a power plant. Enrichment and penetration factors for major and trace elements have been determined thus pointing out the different behaviours of elements according to the chemico-physical properties of fly ash particles to which they are associated, as well as their dependence on the plant operating conditions,