Application of Thermodynamic Models for

During the last decade, significant improvements have been made in the application of thermodynamic models for studying the molten cryolite system used in the Hall–Heroult process. The objective of this study is to enhance the understanding of this process and facilitate advancements in bath chemistry and molten metal processing. To achieve this, thermodynamic modeling was employed to explore the operating windows in the reduction of alumina in molten cryolite, examining various concentrations of AlF3, CaF2, and Al2O3 in conventional and lithium-free baths. Additionally, the impact of lithium fluoride additions to the bath was evaluated. The results identified conditions that allow for reduced cell voltages and lower bath temperatures, suggesting a novel modeling approach that revisits fundamentals and challenges existing paradigms. This research is considered a pivotal innovation in identifying potential modifications in bath chemistry aimed at improving energy efficiency and productivity in modern prebaked Hall–Heroult cells.