Kinetics of Scrap Melting in Iron–Carbon Bath

Abstract

The melting kinetics of scrap is a limiting factor in controlling the temperature trajectory and scrap ratio of BOF process as well as the energy consumption and productivity of EAF steelmaking. Prediction of the melting rate of scrap, the mass transfer coefficient of carbon, and heat transfer coefficient between the melt and scrap can provide a theoretical basis for the process modeling of BOF and EAF. In this paper, the interface between melt and scrap in melting process is analyzed, and the moving boundary layer concept is optimized. Through Fick’s law and Fourier equation state, combined with the heat and mass balance of moving interface, the theoretical analysis model of scrap melting is established and programmed. The effects of bath temperature on the melting behavior of scrap in the liquid melt are studied. The results show that as the bath temperature increases, the formation time and maximum thickness of solidified layer decrease; furthermore, the time to reach the final stable melting rate and the initial heat transfer coefficient decreases. However, the final stable melting rate increases; moreover, the final stable heat transfer coefficient and mass transfer coefficient initially increase and then decrease.