Preventive Treatment of Anode Effects Using on-Line Individual Anode Current Monitoring

Abstract

Anode effects (AE) are considered a nuisance for aluminium production due to the numerous negative impacts that they generate in an electrolysis cell. Previously, great efforts have been deployed to minimize the occurrence of this event. Using online anode current monitoring, Alouette introduced an algorithm to detect abnormalities prior to an AE, allowing sufficient time to apply a corrective action before its occurrence. Several sets of strategies were tested to evaluate the best approach to correct the situation without generating additional problems in the cells. Finally, individual anode currents measurements were connected to the cell control system of two pots to automatically launch preventive treatment of AE. A decrease in the total number of anode effects along with an increased cell stability is noticeable. Other indicators, such as anodic incidents, alumina dosage and metal purity were also compared to make sure that no deterioration in the cell conditions occurred over time.