Maximizing Green Anode Slots Height through a Rigorous Methodology and Finite Elements Modeling

Abstract

Anode slots benefits are maximized when they are high enough to last the entire anode service life: around 450 mm height for the AP30 technology. The most cost effective method for making slots is to form them at the green stage, directly in the vibrocompactor or press. However, plants struggle to form slots higher than 300 mm due to cracks and segregation in the anode. The alternative is to saw the slot in the baked anode but it is CAPEX and OPEX intensive. The challenge has been taken by RTA and Alouette Smelter to form 400mm high slots. Each step of the anode manufacturing and handling process was reviewed through an in-depth risk analysis, teaming up finite elements modeling specialists with process, production and equipment manufacturing experts. Technical solutions were found to increase the height of the slots and to ensure a low scrap rate through new slot design and adaptations to the existing transport and handling equipment.