Higher Baking and Production Levels in Anode Baking Furnaces and Associated Challenges

In the aluminium industry anode baking is often one of the most critical steps to achieve the appropriate anode quality in a safe and cost effective manner. Furthermore, many plants aim to increase the baking level and/or their production. This requires the baking furnaces to be operated at higher temperatures and shorter anode cycles, all while keeping the process safe. To achieve this, the process has to be optimised to avoid the risks associated with unburnt volatiles and an uncontrolled pitch front as well as excessive temperature increases. The present paper describes projects that were simultaneously executed in two of Rio Tinto’s North American smelters and describes the work performed to achieve both a higher baking level and higher production. Optimisation of the baking curves is discussed, along with the issues that arose during the project and the solutions that were put in place.