Modeling of metallurgical emulsions

Emulsification behavior caused by gas bubbles rising through a slag/metal interface has been studied in both a thin-slice model and a three-dimensional model using low-temperature oil/aqueous and oil/mercury analogues. A generalized model characterizing the transitional volume of droplets entrained in the upper phase in the emulsification process was developed. The transient volume of “metal” entrained,V _d(t), following the start of bubbling followed the relationV _d(t) =V _∞(1 −e ^(t/Τ)). This model is also of general significance to other metallurgical emulsification processes, such as those induced by iron ore reduction and top blowing, regardless of the mechanisms of droplet generation. Based on this model, the birth rate and mean residence time of droplets dispersed by rising bubbles can be quantified. Dimensional analysis was used to express the volume of lower liquid carried up into the emulsionper bubble, thereby allowing better estimates of the droplet birth rate in a practical emulsification process induced by bottom blowing. Emulsification behaviors in industrial in-bath smelting processes were interpreted with the present modeling results. Formerly Graduate Student, Department of Mining and Metallurgical Engineering, McGill University,