Mathematical Modeling of the Melting Rate of Metallic Particles in the EAF under Multiphase Flow

The sponge iron or Direct Reduced Iron (DRI) is an important feedstock in the Electric Arc Furnace (EAF). The main sources of iron units for the EAF can be steel scrap, DRI, hot metal and combinations of these materials. The EAF has become a melting reactor and its melting rate plays a key role in furnace productivity. In this work, the melting rate of porous metallic particles is analyzed employing CFD tools, having the computational domain of an industrial size EAF. The molten pool is comprised of two liquid phases, steel and slag. In order to compute the melting rate as a function of particle size and arc length, three sub-models were developed, one computes the instantaneous power delivery as a function of arc voltage and arc length, the second one computes the velocity and temperature fields and finally the third sub-model computes the melting rate. Comparisons of melting rates when the particles are immersed in its own melt and the case where immersion is carried out in the steel/slag system is included in the analysis. A contribution from this work is a more realistic approach to compute the convective heat transfer coefficient using the estimated values of the velocity fields.