ON FLOATING ZONE MELTING OF HIGH PURITY IRON.

From the zone refined specimen, only Co, Cu, Ni and Si were detected as the remained metallic impurities. O and N were effectively removed by zone melting in dry H////2 and wet H//2, but C was hardly removed even in wet H//2. The overlap method was found to be an effective technique, as compared with an usual zone refining method, for multiple zone refining to protect ″melt in″ or diffusion of impurities from the unpurified section adjacent to the starting end.