A Microstructural and Kinetic Study of Molten Aluminium Oxidation in Relation to Dross Formation

ii Oxidation and dross formation on molten aluminium is estimated to directly cause losses of tens of millions of dollars per annum to the Australian smelting industry. Although there has been significant study of molten aluminium oxidation over the past few decades, the formation mechanisms are still not fully understood. There is also lack of reliable and useful kinetic data that can be applied to computational simulations of industrial melt handling processes involving the oxidation of either quiescent pools or turbulent transfers of molten aluminium. There is additional uncertainty in the literature relating to the physical processes underlying molten aluminium oxidation, and the microstructural evolution of the growing oxide film. Past oxidation studies have been confounded by the detrimental effect of the pre-existing oxide ubiquitously present on aluminium specimens. Recent studies conducted at The University of Queensland have indicated a way forward in this respect, with the development of an experimental technique that enables the melt surface to be skimmed free of pre-existing oxide prior to each oxidation experiment. This project is based on previous outcomes and expands on them to create new insights into the oxidativ