Wetting of Na3AlF6-KF-AlF3 based electrolytes on graphite cathode material associated with melt penetration

摘要

Na3AlF6-KF-AlF3 based electrolytes have been intensively studied in recent years to reduce operating temperature in aluminum electrolysis process. This work is aimed to investigate the wetting process of this lower temperature electrolyte associated with melt penetration into graphite cathode material. Contact angles of the electrolyte on the graphite samples were measured using a modified sessile drop method and the melt penetration in the graphite samples were inspected by SEM-EDS technique. Both the wetting and the penetration processes were found interacting each other and varying with changes in electrolyte compositions (CR and KF addition), temperatures (900-940 °C).