Maximum Anode Effect Voltage

摘要

Anode effects occur in industrial aluminum cells when the dissolved alumina concentration becomes too low during normal electrolysis. The anode effect is characterized by an abrupt and rapid increase in cell voltage, resulting from an increase in ohmic voltage due to dewetting of anode surfaces and subsequent increased coverage by gas bubbles. The cell voltage during anode effects may vary depending on anode geometry and cell conditions. The max AE voltage is typically 25-30 V for prebake cells and 30-40 V for Soderberg cells. Differences in the emission rates of perfluorocarbon (PFC) gases for different cell technologies are associated with the dissimilarity in anode kill strategies, specifically, the manner and timing of short-circuiting anodes during anode effects.The objective of the current work is to achieve a better understanding of the factors influencing anode effect voltage in industrial prebake and Soderberg cells. Additionally, a better understanding of the relationship between AE volts and PFC emissions can lead to a more effective strategy for reducing anode effect minutes and resulting PFC emissions.