A new type of metal matrix composite with a composition of Al2O3-33.8Fe-26.2Ni (wt.%) used as inert anode was developed in this article. Aluminum electrolysis with this anode was conducted for 12 hours at 850℃ with a 1.8:1 molar ratio of cryolite which consisted of NaF-AlF3-8wt%NaCl-5wt%CaF2-4wt%Al203. The anodic current density was 0.75A/cm2. Electrolysis carried out smoothly with relatively stable cell voltage. Electron Probe Microanalyzer results showed that a film on anodic substrate was characterized by two layers. The outer oxide layer were Na3AlF6 and FeAl2O4, while the inner layer was complicated cermets, including A12O3, NiO and FeAl2O4 ceramic and Ni3Fe, Ni3AI metallic phase. These phases in inner layer were dispersed each other. The anodes showed good performance in terms of electronic conductivity, anti-oxidation and anti-corrosion, thermal shock resistance, as well as mechanical robust. The wear rate of the anode is 19 mm per year, and the purity of aluminum produced is 98-99%.
展开▼
