Impact Of Electromagnetic Stirring (EMS) On The EAF Process

Abstract

Electromagnetic stirring has a potential to play an important role in the modern electric arc furnaces as they often operate with high integrated power input and short tap-to-tap time. The high carbon content in the complex charge mix (such as pig iron or hot metal) and high oxygen consumption also require a high decarburization rate in the process. The intensive bulk stirring of the melt will promote the decarburization after the carbon content is lowered to the diffusion control range and therefore increase the yield of injected oxygen. Stirring of the melt bath will give a more homogeneous distribution of temperature and chemical composition and improved kinetic condition for slag/metal reaction. The high rate of mass transfer in the steel bath will promote the slag reduction and push the carbon-oxygen reaction closer to the equilibrium. The decrease of oxygen activity in the steel and the FeO+MnO content in the slag will save the deoxidants (FeSi or Al) used for killing the oxygen in the downstream ladle furnace operation. The stirring will increase the scrap melting rate, reduce the melt surface superheat, reduce the heat losses to the furnace wall and roof during power on period, and thereby reduce the electric energy consumption. The water modeling results also show that EMS will prevent or delay the vortex formation during EBT tapping which will reduce the carryover slag amount to the tapping ladle. The current paper will summarize the impact of EMS on the EAF process operation and the potentials for improvements in productivity and operating cost based on the experimental results and reference plants data