1992 Volume 32 Issue 10 Pages 1047-1057
Coke is the most widely used solid fuel in iron ore sintering. Generally coke is blended with the other sinter mix components dry before granulation. Several studies in the literature have shown that, in addition to the properties of coke, e.g., size distribution, the delayed introduction of coke into the sinter mix, e.g., added towards the discharge end of the granulation drum, affected sintering and the sinter quality parameters. This study was initiated with the view to determine if the granulation practice at the sinter plant of The Broken Hill Proprietary Co., Ltd. (BHP), Rod and Bar Products Division (RBPD) could be altered to improve the positioning of coke in the granulated sinter mix. As pilot-scale sintering studies did not indicate positive results, further studies were carried out including the use of longer granulation time, and the use of optical microscopy to characterise the structure of the formed granules. Results showed that the positioning of the finer coke particles depended on when the coke was introduced into the granulating mix. In contrast, the large coke particles remained free, i.e., unattached to other materials, regardless of the coke addition technique. When the fine coke particles were well-embedded into granules their combustion rate was decreased; this broadened the width of the coke combustion zone resulting in lower sinter productivity.
