Effect of Physiochemical Properties and

This study investigates the relationships between the dissolution rate of alumina and its specific physiochemical properties, as well as the chemistry of the bath used in the electrolysis process. The focus is on various factors including electrolyte composition, operating temperature, and superheat. Key physiochemical properties of industrial alumina samples, such as moisture content, loss on ignition, surface area, and phase composition, were measured. The dissolution of these samples was monitored by a visual recording system in quartz crucibles with different bath compositions. Results indicate that the dissolution rate increased with higher losses on ignition and surface area, demonstrating a significant influence of operating temperatures and existing alumina concentrations in the electrolyte. Minor changes in bath compositions and superheat were found to exert less influence on the dissolution rate compared to these primary factors. Similar trends were observed in experiments with lab-calcined alumina samples, underlining the importance of these findings for optimizing the Bayer process in industrial aluminum production.