Abstract
Two types of iron ores were reduced partially until some levels of metallization in a laboratory fluidized bed. These fines were briquetted under cold or hot press machines. Then the briquettes were isothermally reduced in a thermobalance at 900-1200°C with CO-CO2 mixture to elucidate their kinetics, imaging semi reduced iron burdens in a blast furnace.
The briquettes from Australian are indicated a severe reduction delay in whole periods above 1100°C due to the formation of liquid slag. The addition of 2% MgO into briquettes released fairly this delay. The briquettes from Brazilian are poor in gangues indicated no reduction delay even at 1200°C.
The briquettes seemed to be reduced according to the first order reaction equation on remained wustite. The obtained rate parameters kM were almost similar between cold and hot briquettes in spite of more density and crushing strength for the latter than the former, because smooth gas diffusion was ensured insides due to both briquettes having relatively large porosities.
Crushing strength of hot briquettes reached more than 1000 N/briquette.
