The Behavior of CO 2 Supersonic Jets in the Converter Slag-Splashing Process

A numerical model was developed to investigate the possibility of using CO 2 to replace conventional N 2 for the converter slag-splashing process and, thus, promote the recycling of CO 2 in the steel industry. The validity of the numerical model was demonstrated using one-dimensional isentropic flow theory and experimental data. By comparing with N 2 and O 2 , it was found that CO 2 has a lower velocity and dynamic pressure, higher temperature at the exit of the oxygen lance, and the difference between the three gases decreases gradually with the increasing of axial distance. The oxygen lance is required to have excellent stirring and splashing performance simultaneously for the CO 2 slag-splashing process. The five-hole oxygen lance with a central nozzle combines the advantages of single-hole and four-hole oxygen lances, with higher impact force, slower decay of dynamic pressure, higher impact area, and more tremendous average turbulent kinetic energy at a low lance position, providing a better choice for slag splashing. Decreasing the axial distance, increasing the CO 2 stagnation pressure, and raising the CO 2 preheating temperature could improve the CO 2 jet performance by different degrees. This work provides a theoretical basis for the application of CO 2 in the converter slag-splashing process. Graphical Abstract