Process-related patterns in dioxin emissions: a simplified assessment procedure applied to coke combustion in sinter plant☆

Analyses for dioxins present in the windlegs of sinter plant using coke breeze as fuel which were carried out originally to monitor the 17 targeted isomers have been re-examined in order to establish the variation in isomer profiles with location of the sampling point relative to the beginning of the sinter strand. The analysis has been carried out using peak height as a measure of isomer abundance to allow assessment of a large number of peaks reasonably rapidly. It is found that the isomer profiles of the tetra- to heptachlorodibenzofurans, which dominate sinter plant emissions in the exhaust gases from the majority of the bed are similar. However, analysis shows that whilst some isomers contribute a similar percentage of the isomer group at the beginning of the strand, there are more, which vary significantly from the mean. Ways in which this localised difference in isomer distribution could arise are discussed.