Effective Utilization in Resources with Simultaneous Synthesis of Iron Carbide and Rutile by Thermochemical Reactions of Ilmenite Ore

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The titanium industry consists of paint pigments and metallic products. As their main feedstocks, natural rutile (TiO_2) and ilmenite ore (FeTiO_3) are known. In the future it is supposed that the latter has a potential to be useful as the main resource because the former is diminishing.In the present work, we have tried to produce both iron carbides and rutile (TiO_2) from ilmenite ore by utilizing pyrometallurgical reactions between solids and reducing gas, imaging that both products could be subsequently separated by any means. Iron carbide is recently focused as an alternative iron source to steel scrap. If this process is operated successfully, it could supply both valuable titanium and ferrous materials simultaneously into each industry and generate benefits from wastes. As for iron carbide, we have reported several papers in which it was proved that traces of sulfur in reaction gas makes iron carbides more stable without any soot precipitation from many types of iron ores.Natura … More l ilmenite ore (Quilon, Kerala, India. Main mineral : FeTiO_3) was employed for reaction tests.Finally, this research was concluded as the followings.Simultaneous synthesis of iron carbides (mainly cementite Fe_3C_2, θphase) and rutile (TiO_2) from natural ilmenite ore (mainly FeTiO_3) were investigated by thermochemical reactions with H_2-CO or H_2-CH_4 gas mixtures having low sulfur pressures incapable of forming FeS at the temperatures of 1073-1273K.For the ilmenite samples it was confirmed that traces of sulfur in both gas mixtures produce iron carbides stably without free carbon, analogous to our previous results obtained for iron ores.In the first stage, partial conversion from ilmenite to rutile and metallic iron proceeded and then iron carbidization occurred with further reduction of rutile. Both gas mixtures provided iron carbide and lower titanium oxides such as Magneli phases (Ti_nO_<2n-1>, 4≦n≦9, namely TiO_<2-x> ) and/or Ti_3O_5 rather than rutile during the later stages.Ti_3O_5 andTi_4O_7 phases tended to exist with increasing temperatures rather than TiO_2 Only Ti_4O_7 was identified as one of the Magneli phases. Less