Spent pot lining is the most common waste product generated by an aluminum smelter. It consists of the carbon and refractory lining that cover the bottom and sides of the electrolytic pots, and is extracted at the end of a pot’s useful life. The quantity of spent pot lining produced depends on the number of pots relined, which varies from year to year according to the life cycle of the pots.
In 2010, we implemented solutions to increase the recycling and valorization of the spent pot lining generated in Québec. The carbon portion is valorized as a fuel source, while the refractory linings are recycled at cement plants in the United States, which use them as a mineraliser.
In 2012, the recycling rate for spent pot lining shipped to outside sources was 100%. These shipments significantly exceeded annual production in Baie-Comeau since a large portion of the spent pot lining it had been stockpiling onsite was sent out and fully recycled. This explains the recycling rate above 100%.