Constellation, le dépôt institutionnel de l'Université du Québec à Chicoutimi

Résumé

Aluminerie Alouette recently studied the relationship between electrolysis cell operation and their impurities’ balance. It was observed in some cases that the concentration of impurities in the metal is lower than expected from raw material mass balance, mainly for iron, gallium, titanium and vanadium. These cells were inspected to find the cause of the imbalance; methodology and results of the inspection are presented in this paper. Analyses regarding cell performance were conducted with regard to cell impurities distribution (metal/crust/gas duct). The factors correlating these phenomena are discussed, with focus on operational results. It was found that anodic incidents are strongly related to very low impurity concentrations in the aluminium and it was possible to develop an indicator at Aluminerie Alouette to quickly detect anodic incidents using vanadium content in the aluminium. This process tool is presented and discussed in the article.