2010 Volume 96 Issue 4 Pages 141-149
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.
In this work, influence of coal brand and potassium addition (0.4 mass% as K2O) on self reaction behavior of the briquettes under a blast furnace simulated heat and load was investigated to explore more efficient blast furnace operation.
The shrinkage of briquettes during reaction and the crushing strength of briquettes after reaction corresponded mostly to their reaction behavior with or without potassium.
Both gasification of coal and reduction of iron ore during self reaction of briquettes were evaluated and it was found that the former rates were a little smaller than the latter ones as a whole, irrespective of the coal brand and addition of potassium.
Gasification and reduction of lower rank coal bearing briquettes occurred in lower temperature than those of higher rank coal bearing briquettes. Inversely, the carburization and melting of the latter briquettes proceeded at lower temperatures than those of the former briquettes.
The catalytic effect of potassium on gasification and reduction was more remarkable for higher rank briquettes than lower rank briquettes. Moreover, potassium enhanced the softening, carburization and melting of both rank briquettes at lower temperatures.
