Evaluation of Iron Ore Concentrate and Micropellets as Potential Feed for Sinter Production

Abstract

ABSTRACT The use of iron ore concentrate and micropellets as sinter feed was evaluated. Five mixtures containing different proportions of concentrate and micropellets, together with iron ore fines, were granulated and sintered in a pilot scale sinter plant. It was found that the addition of iron ore concentrate and/or micropellets to the sinter feed resulted in a significant increase in permeability of the granulated bed, but a large drop in sinter production rates. Although the introduction of iron ore concentrate and/or micropellets to the sinter mixture did not significantly impact sinter strength or reducibility (as measured through tumble – (TI) and reducibility indices (RI)), it severely impacted on their strengths during reduction (as measured through RDI−3.5 mm and RDI−0.5 mm). The introduction of iron ore concentrate and micropellets resulted in a general increase in the amount of fines that form during reduction, exceeding the maximum acceptable levels (RDI−0.5mm maximum 5%) set by industry. Sinters containing high amounts of micropellets experienced a more severe degradation than the concentrate-rich sinters. It is therefore more viable to use iron ore concentrate in the sinter feed as higher production costs are associated with the production of micropellets. Sinters produced through concentrate addition also generate less fines on reduction.