Transient thermal modelling of green anode cooling in the aluminium industry

Abstract Anodes, which are used in electrolytic aluminium production, are made by mixing dry aggregate (petroleum coke, rejected anodes, and butts) with coal tar pitch, compacting the resulting paste (green anode), and baking (baked anode). After compaction, the anodes are cooled to maintain their structural integrity before being sent to anode baking furnaces. This study focuses on developing and validating a 3D transient thermal model to simulate the green anode cooling process. The model predicts temperature distribution in the anode during the cooling phase. This will help assess different cooling strategies. Heat transfer by convection (in air and water) and radiation (only in air) was incorporated into the boundary conditions to predict the thermal behaviour of the anodes. Various cooling media, such as air, water, and water spray, were used in free or forced convection modes. The model predictions were validated by comparing them with experimental data obtained from laboratory tests on pilot green anodes of about 10 kg. The results demonstrated a strong correlation between the simulated and experimental temperatures, validating the model. Thus, the model can be used to identify efficient cooling strategies and, consequently, improve anode cooling processes, leading to enhanced product quality.