METHOD FOR DEPHOSPHORIZING MOLTEN IRON CONTAINING CHROMIUM

摘要

PURPOSE:To raise the degree of oxidation of slag and molten iron and to improve the efficiency of dephosphorization by feeding a gas contg. oxygen to the slag floating on the molten iron and the molten iron when the concn. of carbon in the molten iron reaches a prescribed value. CONSTITUTION:An oxidative dephosphorizing agent such as CaO or CaF2 is added to molten iron contg. chromium. A prescribed concn. of carbon above the concn. of carbon which is in equilibrium with chromium and oxygen under 1atm partial pressure of carbon monoxide is set. At the time when the concn. of carbon in the molten iron reaches the prescribed value, gaseous oxygen is blown into slag floating on the molten iron and the molten iron. While the concn. of carbon in the molten iron is kept high, the amount of chromium oxide and the total amount of iron oxide in the slag and the molten iron are increased.