Metal-alumina cermet inert anode in a 100A bench-scale cell for aluminium electrolysis

摘要

A bench-scale laboratory cell of 100A using metal-alumina cermet inert anode in cryolite-alumina electrolyte at 960℃ was carried out in a graphite crucible.The dimensions of the graphite crucible were φ160mm×H250mm.The cell was built with a graphite cathode of 150mm×40mm×15mm and an inert anode of 120mm×80mm×15mm.The purity of aluminium metal produced was 98％-99%,the impurity were mainly Fe,Ni,Co.The anode gas consisted of 98％-99％ O2 which was analyzed with an Orsat apparatus.The back EMF value of the cell at 960℃ was 2.45V, which was 0.25V higher than the theoretical alumina decomposition potential 2.2V After 10 hours electrolysis.the anode was only little corrodcd.Hence it was confirmed that the electrochemical reaction occurred in the electrolysis cell was the decomposition of Al2O3 in the bath and the anode used was incrt.