Research Progress on Bubble Behavior During Bottom Blowing in Ladles

Bottom-blown argon stirring is widely applied in ladle refining to improve the uniformity of steel temperature and composition, enhance steel–slag reactions, and promote inclusion flotation. Its refining performance is closely associated with bubble dynamics in the molten steel. Bubbles generated at the bottom undergo expansion, rising, deformation, breakup, and coalescence, driving the circulation of the surrounding liquid. The resulting bubble plume and gas–steel–slag interfacial behavior are therefore strongly affected by these processes. However, measurements in industrial ladles remain difficult because molten steel is opaque and operates at extremely high temperatures, while interactions among different phases further complicate direct observation. Numerical simulation, usually combined with physical experiments, has consequently become an important means of studying bubble behavior. This review summarizes recent studies of bubbles in ladles, with attention given to Eulerian–Eulerian, Eulerian–Lagrangian, and multiscale modeling approaches. Relevant water-model experiments and measurement techniques are also reviewed. Current limitations and future research needs are considered with respect to model coupling, quantitative experimental validation, and the application of numerical and laboratory findings to industrial ladle refining.