Ohmic interelectrode voltage drop in alumina reduction cells

The large gas bubbles underneath the anode in Hall-Heroult cells not only affect the ohmic interelectrode resistance by decreasing the cross-sectional area available for current transport. They also exhibit a strong effect on the current distribution in the bubble-free layer, substantially increasing the resistance. Available relationships applied in aluminium industry do not take this effect into account. A review on attempts to describe the interelectrode resistance is given, and an improved relationship derived from a finite element model is presented.