Development of new process for rapid pig iron making in high oxygen potential at low temperature in order to reduce carbon dioxide gas emission

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The Tatara was the traditional ironmaking process in Japan and came from Korea in the late of 6 centuries. It had the box-type furnace with 1.2m height using clay and produced mainly pig iron from iron sand and charcoal. This process was the unique way in the world for producing pig iron In the middle of Meiji period, the Tatara was improved and the furnace with 3m height was constructed using firebricks. The furnace was called as "Kakuro". However, the Kakuro process was not so suitable for ironmaking from powder iron ore because of its flying. The reduction rates of iron oxides ground with graphite by a ball-mill were measured using a high temperature X-ray deffractometer. Increasing the milling time, the starting temperature of reduction decreased by 30 to 100K and the activation energies of reduction from hematite to magnetite and from magnetite to wustite decreased. That from wustite to iron increased. The surface of Fe1-xO was analyzed using STM analyzer. The surface broken in va … More cuum was random. When it was heated in vacuum for 15 min. at 800℃, the step with <110> direction grew and the surface construction of (1x1), (4x2) and the mash with about 3nm square appeared on the surface of (100). After heating in vacuum for 15 min at 1000℃, all surface was occupied with the mesh. The mesh meant that the clusters of Fe atomic vacancies in wustite appeared on the surface. The initial reduction of wustite on the surface radiated by H+ ions showed that the mesh structure disappeared and the small iron particles with 2-3nm diameter stayed on the surface. The dielectric constant and magnetic permeability of magnetite were measured to have the maximum near 2.45GHz of microwave. The carbon-composite pellet of about 10g was heated to 1370℃ for 5 min using 3kW microwave and produced pig iron. The increasing rate of temperature depended on the weight of pellets and not on the diameter of iron are powder. The concentration of impurities of pig iron was lower by one tenth than that of pig iron produced in blast furnace. The continuous process of pig iron making by microwave using the mixture of iron ore and coke powder was examined. Two problems were pointed out that insulators absorbed microwave and the absorption efficiency of microwave energy into resources was low. The new types of microwave furnace were proposed. One is the furnace that microwave beams are concentrated in the center of furnace and another is the rotary kiln type microwave furnace. Less