Particles of hematite ores in a porcelain boat were reduced and carburized at 823∼1223K by H₂-CO mixtures under low sulfur pressures where metallic iron remained stable.Within major of these various conditions nearly one hour reaction could convert their particles completely to iron carbides such as mostly Fe₃C. It was found that traces of gaseous sulfur makes iron carbides enough stable rather than free carbon or metallic iron. Their conversion yields were insensitive to inlet H₂/CO mole ratio and ore type. Total sulfur contents in products obtained for lower sulfur pressures were as low as conventional reduced irons.