Analysis of bloated droplet theory using steelmaking process models

There is significant evidence that droplets generated in steelmaking "bloat" due to the inability of gas generated from the decarburisation reaction to escape from the surface of liquid metal droplets. A model to describe this behavior was developed by Brooks, Subagyo, Coley and Pan based on their own experimental work and calculations and previous studies by Fruehan and co-workers. This approach has been successfully incorporated into an overall process model of oxygen steelmaking. A unique feature of this model is an evaluation of the decarburization kinetics of individual metal droplets in the emulsion and comparing this to the overall kinetics of oxygen steelmaking. The model suggests that the droplets become bloated and remain in the emulsion for long periods (30+ seconds). This paper evaluates the effects of droplet size and volume fraction on the bloating behavior of droplets and critically examines the repercussions of the new theory on plant design and operation.