Optimization of the anode-stub contact: Effect of casting temperature, contact stress and temperature and surface roughness

Abstract

In electrolysis of aluminum, the contact between the anode and the anode stub is normally facilitated by cast iron. Important parameters are the effect on the anode stub contact resistance from: Casting temperature of the iron,Temperature of the stub-anode couplingUniaxial stress between carbon and cast ironSurface roughness In the current work, standard grey iron was cast at three temperatures, 1430, 1340 and 1250°C, maintaining actual rodding cooling rate, to simulate the tendency of white iron forming during casting. The specimens were subjected to contact resistance measurements with anode carbon at 1 A/cm2 current density, varying the uniaxial stress and temperature. Both stress and temperature increase reduced the contact resistance, while low casting temperature did not affect the resistance significantly. The influence from the surface roughness on the contact resistance was not significant.