A Decarburization Model for a Fe–C Droplet Reacting in Oxidizing Slag

A decarburization model has been developed for a Fe–C–S liquid droplet reacting in an oxidizing slag at high temperature (1580 °C to 1640 °C). The model incorporates the partitioning of oxygen at the slag/metal interface between decarburization at the slag/metal interface and transport into the droplet. The kinetics of nucleation and growth of CO bubbles within the liquid metal droplet have also been introduced to describe internal decarburization. The model parameters were determined using one set of experimental conditions and then used to predict behavior over a wide range of conditions. The prediction was validated for variation of, sulfur concentration, droplet mass, temperature, and droplet carbon concentration. Decarburization was found to proceed in three stages. The model was found to show good agreement for the initial two stages of decarburization: the incubation period and peak decarburization period. This observation suggested that the oxygen partitioning and nucleation kinetics had been incorporated properly. The model failed to predict the sudden shutdown of decarburization at the end stage of decarburization.