Microstructure and Electrochemical Behaviour of some SnO2-based Inert Electrodes in Aluminium Electrolysis

Abstract

Some types of anodes thai could replace die usual carbon anodes in aluminium production by die Hall-Keroult process are based on SnO2. The presenr Investigation deals nidi SnO2-Sb2O3-CuO ceramics having an SnO2. conrent of ≥ 96%), Sb2O3, and CuO being dopants The ceramic pellets, thermally treated at 1400 °C for 4 hours, were analysed by X-ray diffraction and IR. spectroscopy. The structural analysis of the samples evidenced an SnO2(88) type solid solution. All samples were electronically conductive (small negative values of the Seebeck coefficients), having an sanation energy ranging within 0.02 - 0.3 eV.The anodic polarisation curves obtained with those anodes in an electrolyte of 88 % Na3AlF6, 7% Al2O3, and 5% CaF2 were studied- The results were correlated with the microstrucrure of die invesagated samples.