A Transient Model of the Anodic Current Distribution in an Aluminum Electrolysis Cell

In the aluminum reduction technology, the current in a cell is first distributed through a series of anodes before reaching the electrolytic bath and the metal pad. This can be conceptualized as a series of resistances in parallel, each with its own parameters and resulting current. In this work, a transient model of the anodic current distribution is presented. This model tracks the properties of each anode (age, dimensions, presence or absence of slots) and predicts the local current, anode-cathode distance (ACD) and current efficiency throughout the anodic cycle. More complex phenomena, such as the deformation of the metal pad and the ledge formation around new anodes, are also taken into account by simplified laws. The model has been extensively validated based on industrial measurements, and can now be used to gain insight into the behavior of the pot, estimate the local ACD, and guide design and operating decisions.