Numerical Study on the Multiphase Flow Characteristics Generated by CaO-O2 Mixed Top-blowing Method in 120t Converter

Currently, the oxygen lance and CaO served as the primary equipment and material for the injection of oxygen gas and the formation of liquid slag, respectively. Therefore, enhancing the impaction ability of the top-blowing jet and improving the utilization efficiency of CaO are the key objectives in research related to the Basic Oxygen Furnace (BOF) steelmaking process. In this study, a numerical simulation model has been developed to examine the impact of CaO-O2 mixed top-blowing technology on the flow fields of molten bath. The results indicated that the kinetic energy of the high-velocity oxygen jet was absorbed by the CaO particles in the expansion section of the Laval nozzle, resulting in a decrease in the jet's velocity. In comparison to the oxygen jet, the CaO particle jet demonstrated less kinetic energy loss due to its greater inertial force and density, which enhanced the total impaction ability of the top-blowing jet. As a consequence, the CaO-O2 mixing top-blowing jet formed a protrusion area at the bottom of the impaction cavity, thereby improving energy transfer efficiency to the molten bath. Ultimately, the dynamic condition and impaction cavity of the molten bath were enhanced by the use of the CaO-O2 mixed top-blowing technology.