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Studies on molten bath and aluminium contamination with ceramic anodes corrosion products
Author(s) -
Rodean Cristian Paul,
Rodean Simona
Publication year - 2008
Publication title -
pamm
Language(s) - English
Resource type - Journals
ISSN - 1617-7061
DOI - 10.1002/pamm.200810853
Subject(s) - anode , dissolution , corrosion , materials science , electrolyte , cathode , aluminium , metallurgy , oxide , electrolysis , tin , ceramic , metal , inorganic chemistry , chemical engineering , chemistry , electrode , engineering
Two types of tin oxide ceramic anodes with 3 different bulk densities are prepared and tested in a laboratory aluminium reduction cell. During normal electrolysis, the regular chemical dissolution process of anode material should be controlled by mass–transport and subsequent reduction of the corrosion products into the cathode metal. The content of Sn species from each experimental anode in the electrolyte reaches stable values and does not contribute to the time dependent corrosion. Their concentration in metal becomes linear with time, providing that the concentration in the electrolyte remains constant. The mass transport anode dissolution mechanism is experimentally confirmed and it becomes evident that the dissolution rate is largely dependent by the conditions at the cathode, which has a hundred times lower rate factor. The smallest aluminium contamination (under 0.2 wt %) and corrosion rate (under 1 cm/year) were obtained by testing the tin oxide anode, with Recipe 2 (2) – 96% SnO 2 +2%Sb 2 O 3 +2%CuO by our own sintering procedure and with bulk densities bigger than 6.5 g⋅cm −3 prepared. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)