Carbothermic production of aluminium is an important alternative to electrolytic processes and has in fact been identified several decades ago as a potentially feasible and profitable process. The cornerstone principle is to take advantage of the endothermic reduction reaction between carbon and alumina instead of resorting to extreme amounts of electric energy to ionize and reduce aluminium oxide to aluminium. Electric energy is necessary only for heating purposes.
The present study focuses on constructing and solving a steady-state electrothermic model for obtaining the spatial distributions for electric potential, electric field intensity and temperature. The complex issues of reaction kinetics and multiphase flow are handled by an approximation and are not addressed at the present stage, due to the lack of complete validated models. Because of its inherent complexity, the reaction slag is considered a pseudohomogeneous layer.
An electrothermic simulation encompasses important research challenges, due to the limited knowledge of thermophysical properties for high-temperature multicomponent molten slags. Therefore, thermophysical property modeling and a systematic compilation of published data is a necessary and major first step towards enhancing understanding of the process fundamentals. Models are obtained by analyzing measurement data from numerous literature references for the density, viscosity, thermal and electrical conductivity and specific heat capacity of the slag.
The electric potential, field intensity and temperature distributions obtained reveal interesting maxima which indicate localized superheating and lead to important engineering conclusions. The temperature profile calculated will serve as the foundation for the flow problem solution. This computational study will form a basis for future research towards combining the scopes of microscale CFD modeling and mesoscale process modeling into a unified modeling approach.
|Title of host publication||Computational Modeling of Materials, Minerals and Metals Processing|
|Editors||M Cross, JW Evans, C Bailey|
|Place of Publication||WARRENDALE|
|Publisher||MINERALS, METALS & MATERIALS SOC|
|Number of pages||10|
|Publication status||Published - 2001|
|Event||Conference on Computational Modeling of Materials, Minerals and Metals Processing - SAN DIEGO, Canada|
Duration: 23 Sep 2001 → 26 Sep 2001
|Conference||Conference on Computational Modeling of Materials, Minerals and Metals Processing|
|Period||23/09/01 → 26/09/01|