Reduction Behaviour of Fired Low-grade Hematite Iron Ore Pellets in Non-coking Coal

Abstract

In the present research, pellets made with iron ore procured from Ramallakota and Veldurthi mines of Andhra Pradesh has been studied for their reduction behaviours in non coking coal. Chemical analysis revealed selected iron ores were of low-grade hematite type with 26 and 47 % Fe content in them. Iron ore pellets were prepared by addition of 5.0 wt.% molasses and fired at 1573 K for 1 h. At 1123, 1173 and 1223 K reduction temperatures, Ramallakota fired iron ore pellets reduced in non-coking coal exhibited higher reduction rates than that of fired Veldurthi iron ore pellets. XRD patterns revealed complete reduction to Fe and formation of fayalite and hercynite phases in the reduced pellets. SEM images revealed less iron whisker formation in Ramallakota iron ore pellets due to presence of substantial amounts of gangue elements in them. Furthermore, higher reduction rate was attained in the molasses added pellets than those fired iron ore pellets made by addition of bentonite. This enhanced reduction rate in molasses added fired iron ore pellets could curtail energy consumption in ironmaking.