Oxidative removal of Cu from carbon-saturated Iron via Ag phase into B ₂O ₃ Flux

The oxidative removal of Cu from carbon-saturated iron via the Ag phase into B ₂O ₃ flux was attempted at 1 523 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 activity coefficients of Cu ₂O in the B ₂O ₃ flux,γ Cu ₂O _{(in flux)} , owing to 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 is calculated to be 120 at 1523 K. To predict the behavior of solute elements in the Ag phase, a numerical calculation of mass transfer based on Fick's second law is performed and the optimum execution method of oxidative removal of Cu is discussed.