| X-ray fluoroscopy was applied to directly observe the smelting reduction phenomena of iron are at high temperatures ranging from 1400℃ to 1550℃. Two types of reductants, graphite crucible and carbon-saturated molten iron, were used to study the difference of physical behavior. In the smelting reduction by carbon in the graphite crucible, it was shown from the observation results that the smelting reduction proceeded by the following two stages; initial quiet reduction without foaming(stage 1), and next highly active reduction with severe foaming(stage 2). The foaming phenomenon was found to be caused by the inside reaction between carbon in the carburized iron layer and the molten iron oxide(FexO). In the smelting reduction by carbon in the molten iron, it was also observed that carbon should be fully saturated in the molten iron to prevent the foaming phenomena. Prereduction to 30% enhanced the melting rate of iron ore and reduced the total reaction time. Therefore, using iron are in the form of wustite, in the real smelting reduction process, is thought to be most economical. |
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