Abstract: The microstructure of sinters produced from Nigerian Iron ores which consist of hematite and magnetite have been investigated using optical microscopy and X-ray diffraction analyses. The effect of magnetite in the ores is to reduce the quantity of SFCA obtained at any basicity when compared with an ore that is wholly hematite. A microstructure that is essentially SFCA can be obtained in Itakpe ore when basicity is 2.5 and the sintering temperature is 1300°C. The Itakpe iron ore is relatively better than Chokochoko iron ore for production of Sinters of good properties on the basis of microstructures developed during sintering.