2012 Volume 52 Issue 1 Pages 18-25
The oxidative removal of Cu from carbon-saturated iron via the Ag phase into B2O3 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 B2O3 flux by the method proposed in this study. Furthermore, the Cu distribution ratio between the B2O3 flux and Ag, LCu(flux-Ag) (= [mass% Cu](in flux)/[mass% Cu](in Ag)) and the activity coefficients of Cu2O in the B2O3 flux, γCu2O(in flux), owing to the oxygen partial pressure were measured. The greatest value of LCu(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 B2O3 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.