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

Hot metal Desulfurization kinetics were studied experimentally using CaO-Al2O3-SiO2-MgO-TiO2-Na2O slags in the range of 1 773 K to 1 833 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.