An Assessment of the General Applicability of the Relationship Between Nucleation of CO Bubbles and Mass Transfer of Phosphorus in Liquid Iron Alloys

The current paper seeks to demonstrate the general applicability of the authors’ recently developed treatment of surface renewal during decarburization of Fe-C-S alloys and its effect on the mass transport of phosphorus in the metal phase. The proposed model employs a quantitative model of CO bubble nucleation in the metal to predict the rate of surface renewal, which can then in turn be used to predict the mass-transfer coefficient for phosphorus. A model of mixed transport control in the slag and metal phases was employed to investigate the dephosphorization kinetics between a liquid iron alloy and oxidizing slag. Based on previous studies of the mass-transfer coefficient of FeO in the slag, it was possible to separate the mass transfer coefficient of phosphorus in metal phase, km$$ k_{m} $$, from the overall mass-transfer coefficient ko.$$ k_{{\text{o}}} . $$ Using this approach, km$$ k_{m} $$ was investigated under a wide range of conditions and shown to be represented reasonably by the mechanism proposed. The mass-transfer model was tested against results from the literature over a wide range of conditions. The analysis showed that the FeO content in the slag, silicon in the metal and the experimental temperature have strong impact on, km$$ k_{m} $$, almost entirely because of their effect on decarburization behavior.