微量H₂S含有H₂-CO混合ガスによるペレット状炭化鉄の生成挙動

抄録

Using a thermobalance, a hematite pellet was reacted with H₂-CO mixtures at 9731073K to produce an iron carbide pellet. H₂S of low pressures unable to form FeS was added to the mixtures. First, reduction of iron oxides proceeded and then carbidization of metallic iron occurred. Small amounts of H₂S in gas led to iron carbides (Fe₃C, Orthorhombic) with complete conversion rather than free carbon or metallic iron as final products. In later stage of carbidization, higher iron carbide (Fe_2.5C, Monoclinic) appeared partially in lower temperatures. The conditions of higher temperature and low sulfur pressure provided high quality iron carbides having nearly less than 0.03 mass% S. The tests without H₂S provided lower iron carbide contents with much free carbon or metallic iron. Carbidization rates of a reduced iron pellet were analysed by an unreacted core model to investigate this process. The carbidization proceeded more rapidly in lower temperatures.