Abstract
Anode effect (AE) phenomena in aluminium cells can be separated into several categories. Firstly, 'conventional' AEs (>8V) are typically initiated on one or two localized anodes and then, due to an abrupt increase in current density, rapidly propagate to the other anodes in the cell thereby providing the typical emission spectrum of PFCs. Secondly, 'low voltage propagating' AEs (<8V) result from localized AEs rapidly propagating to a limited section of anodes with the cells remaining below conventional AE voltage; these AEs often undergo electrical shorting, especially at narrow ACDs, resulting in rapid self-termination. In contrast, the continuous background emission of PFCs should be categorized as a third type of AE or 'non- propagating' AEs. The fundamental mechanisms that initiate continuous PFCs very likely still apply, but the localised AEs do not propagate sufficiently to other anodes for a cell to exhibit a voltage signature characteristic of a low voltage AE. Copyright © 2014 by The Minerals, Metals & Materials Society.