One of the factors limiting the maximum rate ofcoal injection in the blast furnace is the accumulation of unburntchar .The interaction of unburnt char with slag ,hot metal and thegaseous phases could have a significant influence on charassimilation .This work examines the interaction of a low ironoxide bearing slag with different carbonaceous substrates withvarying levels of ash content (0.05%-12.25%) .Experiments wereconducted in a high temperature tube furnace at 1500°C (2732°F) in an argon atmosphere ,and the slag/carbon/gasinteractions were studied in-situ.The results showed that ash content and compositionof the carbonaceous substrates influenced theirwettability by the slag .With good wetting ,there isa significant decrease in the contact angle from theinitiation of melting .The carbonaceous materialsthat showed good wetting were reacting with the slagphase and resulting in a change in the slagcomposition .The consumption of carbon could occurwhen it is in contact with a slag bearing appreciablelevels of iron oxide ,for example .The kinetics of ironoxide reduction reaction could dictate theconsumption rate of carbon in a char present in theblast furnace during coal injection .The dissolutionof ash components in a char into the slag phase couldalso result in the consumption of char during coalinjection .These research topics are currently underinvestigation at the CRC for Black Coal Utilisationin the School of Materials Science andEngineering ,UNSW ,Sydney ;the investigationpresented here forms a part of the overall study.
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