Influence of nature and particle size distribution on granulation of iron ore mixtures used in a sinter strand

The ore mixture granulation process is described and the granulation fitness of a series of iron ores forming part of the mixture is studied. Good granulation and control of the maximum sintering temperature makes it possible to achieve the optimum sinter structure, formed by a hematite nucleus surrounded by a lattice of acicular ferrites. The granulation fitness of ore mixtures used to manufacture a series of sinters in a pilot plant are also determined. It is verified that sinters with an optimum structure have been obtained. A series of iron ores are classified using the granulation index (G index). The evolution of the G index of ore mixtures used in ACERALIA during recent years is considered and it is verified how improvement of the G index increases productivity and decreases coke consumption in the sinter strand.