Recent Advances in Electrical Resistance Preheating of Aluminum Reduction Cells

This paper explores recent advances in electrical resistance preheating methods used for aluminum reduction cells, a process essential for preparing cathode lining materials for operational conditions. The objective is to examine the performance of current preheating techniques, particularly focusing on the electrical resistance method compared to flame preheating, which utilizes gas or oil burners. A thorough evaluation was carried out, measuring preheating times, which ranged from 36 to 96 hours for cell currents between 176 kA and 406 kA, alongside resistance bed thicknesses from 13 mm to 60 mm. The findings showed that the average cathode surface temperature achieved at the end of the preheating period fell between 800°C and 950°C. Despite these detailed observations, the influence of preheating methods on the overall life of the aluminum reduction cells remains ambiguous, lacking quantifiable conclusions. The discussion also touches upon ongoing work in mathematical modeling related to these processes. The paper concludes with a call for further research to gather real situational data on preheated cells, alongside a summary of expected developments in the field of electrical resistance preheating.