Kinetics of metal/slag reactions during spontaneous emulsification

An approach for accommodating the interfacial area changes in kinetic equations for heterogeneous reactions in the presence of spontaneous emulsification has been proposed. The kinetics were analyzed by incorporating time-averaged interfacial areas in the rate equations. The approach was found to be applicable for the experimental data and to satisfactorily describe the reaction kinetics. In the case of a high-temperature reaction between 2.35 g Fe-5 wt pct Al alloy metal droplets with CaO-SiO2-Al2O3 slag at 1650 °C, it was found that the kinetics follow a first-order relationship with respect to aluminum in the metal, and it was concluded that they were controlled by mass transport in the metal phase. The calculated metal mass-transfer coefficient km was 1.7×10−6 m/s.