HIGH PURITY IRON, HIGH PURITY IRON TARGET, HIGH PURITY COBALT, HIGH PURITY COBALT TARGET AND METHOD FOR PRODUCING HIGH PURITY METAL

摘要

PPROBLEM TO BE SOLVED: To provide a method for producing a high purity metal capable of reducing the concentration of aluminum, silicon or the like being impurities. PSOLUTION: An impurity-containing metal is melted by plasma under an atmosphere comprising active oxygen. Alternatively, to an impurity-containing metal, the oxide of the metal is added, so as to be melted by plasma, and the melted impurity-containing metal and the melted oxide of the metal are made to coexist. The active oxygen or melted oxide oxidizes at least one impurity selected from aluminum, calcium, chromium, iron, niobium, silicon, titanium and zirconium. Successively, it is melted by plasma under an active hydrogen-containing atmosphere. The active hydrogen reduces at least one impurity selected from the group consisting of oxygen, carbon and nitrogen. Thus, the impurities are easily removed from the metal, and the high purity metal can be produced. PCOPYRIGHT: (C)2006,JPO&NCIPI