Study on the inert anode for al electrolysis based on the NiFe2O4 spinel ceramics

Abstract

A kind of cermet inert anode for Al electrolysis based on NiFe2O4 had been studied in this paper. Firstly, the effect of NiFe2O4 pre-sintering temperature on properties of inert anodes was researched, and then the appropriate technological conditions were determined by the orthogonal test. The properties such as density, conductivity, corrosion rate, mechanical property and thermal shock resistance have been used as controlling parameter to obtain the optimum technological condition. The inert anode sized Φ50mm×15mm is prepared and tested as anode for 10h Al electrolysis in laboratory. This anode behaves good corrosion resistance to cryolite molten salt. The result gives that the corrosion rate of the anode was 1.5x10-4g•cm-2•h1 after the 8 h electrolysis, and the purity of the aluminum gained from Al electrolysis test was 92 %~93 %. The analysis shows the main contaminations in the raw aluminum are Fe, Ni and Ag.