(W171)Oxidative removal of Cu from carbon-saturated iron via Ag phase into B 2O3 flux

摘要

The oxidative removal of Cu from carbon-saturated iron via the Ag phase into B 2O 3 flux was attempted at 1523 K. The Cu content was reduced from 4 to below 0.2 mass%, and Cu in the molten iron could be removed into the B_2O_3 flux by the method proposed in this study. Furthermore, the Cu distribution ratio between the B_2O_3 flux and Ag, L Cu(flux-Ag) (= [mass% Cu] (in flux) / [mass% Cu] (in Ag)) and the dependence of the activity coefficient of Cu2O in the B 2O3 flux, γCu(in flux), on the oxygen partial pressure were measured. The greatest value of L Cu(flux-Ag) was found to be 17 at 0.6 atm of oxygen partial pressure. Using this value, the distribution ratio of Cu between the B_2O_3 flux and carbon-saturated iron, L Cu(flux-Fe) (= [mass% Cu] (in flux) / [mass% Cu] (in Fe-C))) is calculated to be 120 at 1523 K. A numerical calculation of mass transfer on the solutes in the Ag phase is performed, and the optimum condition on the removal of Cu by the method proposed in this work is discussed.