Influence of beneficiated sinter grade iron ore fines size on sinter productivity and quality

Abstract

The iron ore sinter structure and its physical and metallurgical properties mainly depend on the raw material chemistry, size, size distribution and sintering process parameters. Pot grate sintering studies have been carried out on iron ore fines of different sizes like –3 mm (mean size 1.46 mm), –6 mm (Mean size 1.95 mm), –8 mm (mean size 2.20 mm), and –10 mm (mean size 2.63 mm) to study the influence of iron ore fines feed size on granulation, sinter bed permeability, sinter mineralogy, sinter physical and metallurgical properties. The experimental iron ore fines consist of –150micron size 14.5 to 15.2% and coarser size was maintained from 10 to 3 mm size. The results showed that sinter with mean particle size 2.20 mm (–8 mm size) showed higher productivity due to better granulation and sinter bed permeability and good physical (strength) and metallurgical (RDI and reducibility) properties due to the formation of high strength acicular SFCA phase with fine porosity. The sinter with iron ore fines mean particle size 2.63 mm showed physical and metallurgical properties within the acceptable range, which is required for blast furnace operation. Sinter with mean particle size 1.49 and 1.95 showed poor sinter strength, RDI and productivity due to poor sinter granulation and sinter bed permeability. Iron ore fines size less than 6 mm and 3 mm was not suitable for sinter making to achieve better granulation and sinter properties.