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a b s t r a c tA 2D, steady-state computational fluid dynamics (CFD) analysis of an industrial electric arc furnace (EAF) is presented. The analysis accounts for the electrode shape and immersion depth, as well as for the dependence of Joule heating on the properties of the slag. The equations for the electric potential, momentum and heat transfer were solved across four distinct regions (i.e. air, slag, ferronickel and firebricks) and the final profile of the slag/metal interface was calculated as a function of the operating parameters of the furnace. The results indicate that the amount of Joule heat produced by the Söderberg electrodes increased with increasing applied voltage and electrical conductivity of the slag; the Joule heat peaked for a value of slag electrical conductivity equal to 3 S/m. A highly conductive slag along with a greater electrode immersion depth was found to facilitate the melting process. The maximum slag velocity values computed were of the order of 0.8 m/s in the vicinity of the electrode tips.

A transient mathematical model was developed for the description of fluid flow, heat transfer and electromagnetic phenomena involved in the production of ferronickel in electric arc furnaces. The key operating variables considered were the thermal and electrical conductivity of the slag and the shape, immersion depth and applied electric potential of the electrodes. It was established that the principal stimuli of the velocities in the slag bath were the electric potential and immersion depth of the electrodes and the thermal and electrical conductivities of the slag. Additionally, it was determined that, under the set of operating conditions examined, the maximum slag temperature ranged between 1756 and 1825 K, which is in accordance with industrial measurements. Moreover, it was affirmed that contributions to slag stirring due to Lorentz forces and momentum forces due to the release of carbon monoxide bubbles from the electrode surface were negligible.

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