A Model of Decarburization and Boil of Iron/Carbon Droplets

A model has been developed for decarburization of iron/carbon droplets in an oxidizing atmosphere containing oxygen and/or carbon dioxide. Mass transfer across the gas-side and liquid-side boundary layers are taken into account as well as decarburization reactions at the interface. A spherically symmetric model was first developed and compared with data from experiments carried out in a tube furnace. This model has been extended to allow for non-uniform mass transfer effects resulting from flow of the oxidising gas over the droplet. Boil is assumed to occur when the supersaturation partial pressure of CO within the droplet exceeds a critical value for nucleation. Predictions of boil time agree well with the measurements for droplets contained in the tube furnace.