Abstract
Anode baking furnaces can have significant emissions of sulphuric gases, SO3 is of particular concern due to its acidity. It can condense to sulphuric acid and result in severe corrosion, as well as giving the “blue plume” of sulphuric acid mist around the chimneys. In addition, SO3 mist is a significant problem for many CO2 capture technologies. The NaCl trap methodology was used for sampling, selectively reacting SO3 with NaCl at 200 °C to form Na2SO4. SO2 and other sulphuric compounds will not react under these conditions. All samples were collected with two traps in series. It was found that sulphur was only present in the first salt trap, and no breakthrough was observed. Analytical sensitivity for the samples was estimated, the main factors determining the level of detection (LOD) are background sulphur from the salt and analytical accuracy in the ICP-MS methodology.