Study of Temperature Profile in the Induration of Magnetite Iron Ore Pellets

Abstract

The pelletisation study of magnetite iron ore fines starts with green balling using limestone and bentonite as additives. Heating cycle of iron ore pellets is one of the prime segments of the whole pelletisation process. Drying, pre-heating, firing and cooling processes are collectively named as heating cycle of the process. A temperature profile is maintained throughout the induration process to meet the required specification of the pellet quality. This paper emphasizes on the effect of temperature profile on the mineralogical, physical and chemical properties of fired pellet in the heating cycle. This study includes the green balling and heating cycle at different temperatures from 800 to 1250 A degrees C in batch processes of magnetite iron ore fines. The mineralogical phase conversion mainly from magnetite to hematite at different temperatures is evaluated by XRD study. The microstructural characterisation, compressive strength and chemical analysis of the indurated pellets are used to analyse the effect of increasing temperature during pellet induration.