| Electric arc furnaces have been used for decades in the melting of scrap iron, the production of ferroalloys, the smelting of metal sulfides and the recovery of copper and nickel from smelting slags. Slag resistance furnaces, one of three types of electric arc furnaces, offer the advantages of continuous operation, longer refractory life and better operating conditions.; However, the use of this type of furnaces has been restricted to the smelting of nonferrous metal ores and the recovery of metals from smelting slags. A better understanding of the phenomena occurring in a SRF is essential for promoting the use of this type of furnaces in the smelting of direct-reduced iron materials and/or shredded iron scrap to produce steel.; Therefore, the objective of this study was to investigate the phenomena associated with fluid flow, heat and electric energy transfer and the melting of solid charge in the bath of a SRF furnace, by means of mathematical and physical modelling.; The rate of electric energy dissipation within the furnace bath depends on the electric conductivity of slag, which is a function of temperature and slag composition, and the furnace/electrode geometry. Correlations of slag electrical conductivity to slag composition and of electrode resistance to furnace geometric parameters were developed.; A mathematical model for solid particle melting in a metal/matte or slag bath was developed. The model results were tested against analytical solutions, in some limiting cases, and experimental data of other investigators. By using numerical data generated by this model, a correlation for calculating the maximum crust thickness around a particle was developed; this technique of obtaining engineering correlations was termed "computer-aided test".; A three-dimensional mathematical model for fluid flow and heat transfer in a three-electrode slag resistance furnace was developed. The insight provided by the model results should be useful in developing criteria for the design and operation of SRF furnaces. |
