Sintering Characteristics of Iron Ore Blends Containing High Proportions of Goethitic Ores

Two ore blends containing substantial channel iron deposit (CID) and Marra Mamba (MM) ores were assessed. The blends granulated well with addition of hydrated lime, which was found to improve the morphology and strength, and consequently the bed permeability of the resultant green granules. Compared with Blend 2 (a simulated industry blend), Blend 1, containing more MM and less CID ores was slightly less permeable but required similar moisture to achieve its optimum permeability. Both blends showed similar sintering characteristics as evidenced by sintering productivity and sinter quality, suggesting that Blend 1 was comparable to Blend 2. This was further supported by observations of sinter macro- and microstructure. Addition of hydrated lime improves the bed permeability and the formation and fluidity of sinter melt, consequently leading to improved sinter yield and strength along with sintering productivity. To achieve sinter return balance, the sinter return ratio had to decrease as the coke addition increased.