Fundamental Factors Determining Laboratory Sintering Results

Abstract

The main purpose of sinter pot studies is to quantify the common indicators of performance viz., mix moisture, productivity, coke rate and sinter quality. For three ore blends—containing 50 mass% pisolite ore and up to 30 mass% Marra Mamba ore—sintering studies were carried out using two laboratory sintering techniques, and the fundamental factors influencing these key indicators were accurately quantified. The study supports previous findings that pre- and post-ignition airflow rates provide invaluable information on flame front properties, sintering time and sinter strength. Sintering results obtained for the two techniques were very different because of differences in flame front properties. Clearly, a good understanding of the influence of flame front temperature, sintering energy requirements, airflow rate and bed thermal capacity on heat transfer and bed airflow resistance is necessary to explain the fundamental sintering behaviour of ore blends. To help quantify these links, the factors governing airflow through a sintering bed and the drivers causing the flame front to descend down a bed were also presented from a theoretical perspective. As expected, both theory and test results show that post-ignition airflow rate, the level of coke in the granulated mix, and endothermic reactions such as calcination were very important factors influencing flame front resistance and, therefore, the sintering performance of ore blends.