抄録
Nagata and coworkers of the Tokyo Institute of Technology have been working on the development of unique ultra high purity iron refinement technology based on an ancient Japanese iron refinement called "Tatara" method. Their findings during microwave sintering of powder metals led to the idea that rapid refinement of iron should be possible by application of 2.45 GHz microwaves instead of relying on burning of carbon for heat production. While joint experiments at the National Institute on Fusion Science (NIFS) proved that high purity iron (1% carbon concentration) with less than 10% of impurities as compared to irons from modern blast furnaces could be produced in a short time, while reducing the carbon consumption to 1/2.
In order to investigate the effect of microwave frequency, the joint experiments with and Forschungszentrum Karlsruhe (FZK) have done using the samples of magnetite powder mixed with carbon powder. As a result, high quality pig iron could be made from powder samples of mixed magnetite and carbon by 30 GHz mm-waves heating in air. However, in case of heating by 2.45 GHz at similar conditions, mainly FeO was produced. Therefore, we expect that there is frequency dependence in the reduction reaction. This paper describes experimental results obtained by millimeter-wave processing.
