Wetting Phenomena in Aluminium Electrolysis

Interfacial tension and wetting phenomena are important in all industrial processes, and the aluminium electrolysis is no exception. The present paper explains some of the basic principles related to interfaces, including the Young equation and principles for computing the shape of surfaces. An analytic solution for calculating the shape of the meniscus formed at the aluminium-bath-sideledge region in aluminium electrolysis cells is shown. A numerical method for computing more complicated shapes in briefly described, and the shape of the meniscus around a rod dipping into cryolitic bath is shown. The shape of gas bubbles residing underneath a horizontal surface is illustrated at different bubble volumes and angles of wetting.
An immersion-emersion apparatus for studying wetting in cryolitic melts is described. The measured extra weight due to wetting (weight of meniscus) for anode carbon in cryolitic melts with variable concentration of alumina is given. It was found that melts with low and medium concentrations do not wet carbon (during immersion), while the anode is well wetted in alumina saturated melts. The mechanism for the anode effect is discussed.