The development of a global model for oxygen steelmaking and its validation against industrial data was reported in Part 1 of this paper. This paper focused on the development of one sub-model on the decarburization reaction in the emulsion zone incorporating the bloated droplet theory. This paper also critically evaluated the current knowledge on the kinetics of decarburization reaction in the emulsion phase and discussed the repercussions of the new model for industrial practices. The decarburization model, in conjunction with the industrial data, indicates that the decarburization rates in the emulsion phase reaches up to approximately 60% of the overall decarburization rate during the main blow. It was found that the residence time of droplets as well as decarburization reaction rate via emulsified droplets was strong function of bloating behavior of metal droplets in the emulsion phase. The estimated residence times of the metal droplets in the emulsion were between 0.4 to 45 s throughout the blow. The influence of variations in droplet size and ejection angle on residence time and decarburization rates via emulsified droplets was also investigated. It was shown in this study that the decarburization rates in the emulsion were accelerated if droplet size was decreased or if the ejection angle was decreased.