Designing And Modeling Of A New Continuous Steelmaking Process PDF Download

"Continuous steel production has the potential to lower the cost of steelmaking as compared to current batch operations. However, experiences from past attempts to develop and commercialize continuous steelmaking processes show that there are several engineering hurdles to overcome. The objective of this research was the development of a fully continuous steelmaking process that would incorporate the lessons from past experiences, address the foreseen challenges, and meet the requirements to justify the possible replacement of the current EAF-LMF steelmaking route. The design of the new process consists of five interconnected vessels. Preheated scrap would be continuously charged, melted, and superheated in an AC Consteel® EAF. Refining under oxidizing conditions would be accomplished in the EAF and in the second vessel called Oxidizer. Reducing conditions would exist in the subsequent vessels (Reducer, Finisher, and tundish). Continuous de-O, de-S, and alloying would be accomplished in the cone-shaped Reducer before additional de-S and alloy additions as well as inclusion floatation and homogenization in the Finisher would ensure a continuous stream of quality steel into the tundish. The invention of this work is three new refining vessels that connect the proven Consteel® EAF to a tundish, supporting fully continuous operation, and adopting the functions of a typical batch LMF. Each continuous reactor would operate at near-equilibrium conditions during steady-state operations. Performance of the new refining vessels was simulated based on fluid-flow, thermal, and kinetic-thermodynamic models that were verified with industrial measurements during the ladle refining at two LMF's. These simulations addressed the foreseen challenges and predicted that the new continuous steelmaking process could meet or exceed current steelmaking requirements. It is expected that the operation of the new continuous steelmaking process would decrease the cost of steelmaking due to increased metallic yield, improved refining, and increased efficiency. The major result of the evaluation of the ladle refining data is the quantified correlation between the mass transfer rate constant and measurable operational parameters. The value of the mass transfer rate constant is paramount for the chemical performance of each continuous refining vessel. Furthermore, the effect of the FeO concentration in the slag and the slag basicity on the de-S rate was quantified. Frequent measurements during SiMn additions in a ladle with bottom, off-center argon injection demonstrated that this alloy rapidly melts and mixes into the steel bath"--Abstract, leaf iv