Amenability to Processing of Manganiferous Iron Ore

Manganiferous iron ore from Karnataka state was investigated to upgrade the iron content with lowering of manganese in concentrate. Mineralogical studies show that it is comprised of microplaty hematite, martite, goethite, pyrolusite, cryptomelane and minor amount of quartz and kaolinite. The sample contains about 51.4% Fe, 4.75% Mn with 8.5% SiO2 and 2.8% Al2O3. The crushed to 1mm and 3mm samples were subjected to reduction roasting using producer gas. The reduction roasting converts the hydrated iron oxide mineral into more magnetic materials which facilitates the magnetic separation at low intensity leaving manganese minerals in non-magnetic. The reduced products were subjected to magnetic separation at very low magnetic field to recover magnetite. The final concentrate containing 64.1% Fe and 2.3% Mn is achieved with a yield of 73.5% from -1mm sample. This product can be blended with the low Mnhematitic concentrate with 65% Fe to generate a pellet feed. *Corresponding author: Shobhana Dey, E-Mail: sd@nmlindia.org, Ph No. +91-657-2349020.