Fundamental Insights into the Sintering Behaviour of Goethitic Ore Blends

Abstract

The main purpose of this paper is to examine the effect of altering the sintering parameters—viz., bed height, suction, and the levels of return sinter fines, coke, mix moisture, and limestone—of two blends, one containing over 50 mass% pisolite ore and the other 50 mass% pisolite ore and 30 mass% Marra Mamba ore. Pre- and post-ignition airflow rates were determined together with the traditional performance measures i.e., sintering time, yield, productivity, coke rate and sinter tumble index. Results from such a study provide useful information on tolerable variations in the sintering process parameters and insights into which are the more important parameters controlling sinter plant performance. Sinter pot test results show significant changes in airflow rates and sintering performance when the sintering parameters were altered, although the two blends did not always respond in the same manner. Many of the obtained relationships (e.g. increasing bed height results in the formation of stronger sinter) are well known, but in this study explanations on why and how the relationships exist are given. It is clear from this study that the temperature of the flame front, which has a significant influence on flame front permeability and the melt formation process, has a very large influence on sintering performance and the strength of the ensuing sinter product.