Effect of the additive concentration on the modification of petroleum coke and anode quality

Abstract Calcined petroleum coke is one of the major raw materials for anode manufacturing, which is used as the carbon source in electrolytic cells for primary aluminium production. It constitutes around 65%–70% of the anode recipe. Therefore, the quality of calcined coke has an important impact on anode quality, which affects the cost, energy efficiency, carbon consumption, and greenhouse gas emissions. Another main raw material for anode production is coal tar pitch. To enhance the anode quality, the interaction between these two components should be improved. The objective of this study is to investigate the effect of coke surface modification, and the amount of additive used on anode quality. An additive at different percentages was used to modify two different cokes. Aromatics and heteroatom‐containing functional groups of non‐modified and modified cokes were identified by FT‐IR and compared to see the effect of the additive concentration on anode quality. Wettability experiments were carried out using the sessile‐drop method since the wettability of coke by pitch and the anode quality are closely related. Anodes were produced and characterized using non‐modified and modified cokes. It was found that the amount of additive used must be adjusted to improve the anode quality.