Ladle Slag Practice ― Bridging the Gap between Theory and Practical Steelmaking Concerns

摘要

The interactions of ladle slag with steel and refractory have been well studied. The refining practices have been developed based on a sound understanding of the thermodynamics and kinetics of the reactions involved. The objective is to control the steel and slag properties to facilitate the downstream activities of casting and ladle turnaround in a cost-effective manner. However, as was evident from the examples presented in this paper, many factors can cause ladle slag and refining operations to be out of control. Ladle slag is interdependent with many other operations in the steel mill, but practices are often developed independently. The following factors must be considered when developing an effective interdependent ladle slag practice: 1. Oxygen content of steel at tap 2. Slag carryover from the furnace to the ladle 3. Duration of the tapping operation 4. Amount of heel in the furnace at the conclusion of tap 5. Tap hole size 6. Order of additions and impact on chemistry 7. Sulfur sources 8. Desulfurization requirement 9. Available materials and their respective costs 10. Influence of practices on yield 11. Influence of practices on quality 12. Effect on ladle refractory 13. Time available to complete the operations 14. Variability inherent in each process.