EFFECTS OF HIGH TEMPERATURES AND PRESSURES ON CATHODE AND ANODE INTERFACES IN HALL-HEROULT ELECTROLYTIC CELLS

摘要

This paper deals with the physical modifications occurring at hightemperatures and pressures at the interfaces found in the anodeand cathode of a Hall-Heroult electrolytic cell. The anode and thecathode are fabricated from carbon blocks, with steel bars insertedand sealed with cast iron. Consequently, two different types ofinterface are found in the anode and the cathode assembly: castironwith steel and cast-iron with carbon. For the investigationpresented here, an experimental setup was built to heat and loadanode and cathode samples. Specific attention was put on thesample preparation, to reproduce real cathode/anode sealingconditions. During the heating and the loading of the samples,fluctuations of electrical and thermal contact resistances wereobserved and related to physical transformation at the interfaces.These transformations could potentially explain the nonhomogeneitiesof voltage and current distribution occurring in aHall-Heroult electrolytic cell.