Oxidation refining of iron using plasma-arc melting

Oxidation refining of Fe using plasma arc melting, by the addition of iron oxide as an oxidizing agent, has been carried out. In this refining process, an impurity element which has higher affinity for oxygen than iron was expected to be eliminated. As the result, decreases in Si, Mn, Al, Ca, Ga, and Zr were observed and 99.996 mass% of iron could be obtained from 99.93 mass% of electrolytic iron by plasma arc melting under oxidizing conditions followed by argon–hydrogen plasma arc melting. Specifically, the removal of Si was found to proceed by the distribution between in the liquid Fe phase and in the oxide phase. In addition, the relation of Si and oxygen concentration in liquid iron was consistent with the data in the literature.