The direct production of iron carbide from iron oxide

Abstract

The reduction experiments of magnetite powder were carried out at 500oC to 850oC under mixture gas of CO-CO2-H2-Ar. The reactions of iron carbide production at each temperature were investigated by Thermo gravimetric analysis, TGA. The fraction conversion for iron carbide formation was evaluated by comparing the relative intensity of peaks from X-ray diffraction patterns of each phase in reacted samples. At the temperature of above 570oC, iron carbide was formed via wustite intermediate, while there was no wustite formation at below 570oC. In order to find out sulfur effect on Fe3C formation, the reduction experiments of the Chinese magnetite ore with high sulfur concentration were carried out. And the reduction rates of Chinese magnetite ores were different depending on their sizes. To investigate the possibility of direct conversion of iron carbide formation from magnetite, the Fe3C formation experiments with high pressure (~10atm) have been carried out by using high pressure TGA. It is found that the direct Fe3C formation can be possible at 500oC.