Hot Metal Desulfurization Kinetics by CaO–Al₂O₃–SiO₂–MgO–TiO₂–Na₂O Slags

Abstract

Hot metal Desulfurization kinetics were studied experimentally using CaO–Al₂O₃–SiO₂–MgO–TiO₂–Na₂O slags in the range of 1773 K to 1833 K. The results indicated that the rate of desulfurization increases with the Na₂O and MgO content in slag increase, the slag basicity increase, i.e., the ratio of CaO to SiO₂, Al₂O₃ and TiO₂ content decrease, and the temperature increase. A mathematical model of desulfurization kinetics has been developed, using which the calculated results of the desulfurization of hot metal are in reasonable accord with the experimental data. The activation energy of the apparent rate coefficient was found to be 172.58 kJmol⁻¹, and the mass transfer coefficient of the slag phase hardly changes with temperature. All of these showed that the desulfurization of hot metal using the present slag system is controlled by the slag phase mass transfer.