• Sulfur Dioxide (SO2)


Sulphur results mainly from coke, one of the two raw materials used in the production of anodes that conduct current in the pot. It is emitted in the potroom mainly during anode combustion, although a percentage of emissions also occur in the baking furnaces. It is increasingly difficult to secure coke with low-sulfur content.
During the combustion of the anode in the pot, some of the sulphur reacts to create carbonyl sulfide (COS) instead of sulfur dioxide (SO2).








Under the environmental performance agreement signed with the Ministère du Développement durable, de l’Environnement et de la Lutte contre les changements climatiques (Quebec ministry of Sustainable development, Environment and Fight against climate change) in 2008, the annual SO2 emissions target was set at 20,500 mt for all three smelters. In 2015, total emissions were of 15,698 mt.


The Baie-Comeau Smelter does not operate an anode baking plant but buys them from other plants. As a result, its emissions are only from the potrooms.