2009 Volume 95 Issue 8 Pages 600-606
The coal composite iron ore hot briquette made by utilizing thermal plasticity of coal is recently developed as agglomerates without binder, which has several advantages to retain high density and strength during reaction at high temperatures. The charge of this briquette to a blast furnace is expected to enable more effectively higher reaction rates at lower temperatures than usual operation. Moreover, utilization of biomass as carbon neutral is essential to construct a sustainable society permitting to conserve global environment and save resources and energies.
In this work, influence of substituting biomass (Cedar wood flour) for one tenth amounts of coal in hot briquettes was examined by carrying out self reaction tests of the briquettes in a N2 gas steam under heat and load in a laboratory scale blast furnace simulator.
It was proved that both briquettes with or without biomass could retain an industrial allowable strength beyond 50 kgf/cm2 after reaction, while the addition of biomass enhanced a little more the shrinkage of briquettes in the higher temperatures above 1000°C.
Both gasification of biomass added coal and reduction of iron ore during their reaction were evaluated and it was found that the former rates were a little smaller than the latter as a whole, irrespective of the addition of biomass.
Carburization to metallic iron began at nearly 1200°C and both briquettes have been melted down at 1400°C due to nearly carbon saturation in metallic iron with a graphite crucible.