Reduction and Gasification Characteristics of A Unique Iron Ore/carbon Composite Prepared from Robe River and A Coal Tar Vacuum Residue

摘要

We have prepared a unique iron ore/carbon composites (IOC) from a low grade iron ore called Robe River and a thermoplastic carbonaceous material. When Robe River which contains iron as goethite, FeOOH, is heated up to 250 to 300°C, the OH groups are removed as H_(2)O, leaving flat pore spaces of 0.8 nm wide between 2.0 nm thick Fe_(2)O_(3) layers. The pore spaces are, however, closed over 300°C by the sintering of the Fe_(2)O_(3) layers. The idea proposed is to insert the thermoplastic carbonaceous material into the pore space of 0.8 nm wide while the pore spaces are opened and to carbonize it to form carbon in the pore space below 500°C. The iron oxide in the IOC thus prepared is reduced very rapidly in inert atmosphere and the carbon retained in the pore space is gasified by CO_(2) very rapidly also. In this work the reaction characteristics of the unique iron ore/carbon composite prepared from Rove River and a coal tar vacuum residue, CTVR, were examined for its direct reduction, indirect reduction in a H_(2) atmosphere, and coke gasification in a CO_(2) atmosphere from the viewpoints of reaction enthalpies and rate parameters. The examinations clarified that the carbonaceous material retained as coke in the pore space of iron ore are very reactive and show reaction characteristics different from bulk carbon.