New Ironmaking Method at Lower Temperature and Higher Oxygen Potential

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Magnetite pellets bearing coal powder were rapidly heated in Ar atmosphere at an elevated temperature. They were reduced and then melted to be molten pig iron during 10 to 15 minutes at the lowest temperature of 1350℃. At the end of reduction, oxygen potential in a pellet was about 1x10^<-14> atm and then phospher and sulfer contents were very low. The same results were obtained for using the mixture of iron ore and coal powders in a alumina crucible.Reaction between graphite and iron proceeded more rapidly to produce molten pig iron than carburization and melting of iron by CO gas.Insite observations of reduction of iron ore mixed with graphite powder were carried out using High temperature X-ray difractometer. When iron ore and graphite powders were milled together and the diameter of graphite was les than 10 μm, the starting temperature of reduction from Fe203 to Fe304 decreased.Single crystal of FeO was deduced by Ar-CO gas mixture and formed thin layer of Fe on the surface. The rate of iron layer formation made rapid higher temperature than 1050℃ and was cyclically proceeded and stopped under the lower partial pressure of CO gas.As the traditional process of lower temperature ironmaking, "Tatara" furnace was investigated.