Sintering tests, involving airflow measurements before and after bed ignition, were carried out on three optimized iron ore blends-containing only hematite (HAEM), hematite with pisolite (PISO), and hematite with pisolite and hematite-goethite (PIMM)-to assess the resistance of the flame front and associated regions. Results showed that post-ignition airflow rates for the three blends were comparable for the same pre-ignition airflow rate, indicating that reactive ores i.e. pisolite and hematite-goethite ores, did not have an adverse effect on flame front resistance. For the PIMM blend, increasing the level of fines (minus 0.15 mm fraction) also did not have any effect on the flame front resistance. Reducing the coke level in all the three blends and increasing basicity decreased the value of the resistance. The resistance was shown to be a strong function of green bed airflow velocity and semi-empirical equations, with single variables, were derived to characterize the ‘sinterability’ of iron ore mixes.
The Iron and Steel Institute of Japan