Increasing reactivity of burden for the blast furnace can decrease temperature of the thermal reserve zone and reducing agent for producing pig iron. Carbon iron ore composite is considered to be a candidate of high reactive burden. Reactivity of the carbon iron ore composite can be improved by an increase in reactivity of carbon. It is known that Redox reaction of iron enhances the gasification reaction of carbon, therefore carbon supported by iron can accelerate the reaction of the carbon iron ore composite.
In the present study, the newly designed carbon iron ore composite consisting of biomass char coated with submicron iron oxide powder and iron ore fines was proposed to improve the reduction rate. These submicron iron oxide powders can be generally produced by the fluidized roasting of pickling waste liquor of steel sheet in the steel works. These iron oxide powders with submicron size directly attached to carbon could work as a catalyst to increase the gasification reaction rate of carbon. It was confirmed that addition of submicron iron oxide powder to the carbon iron ore composite with biomass char enhanced its reactivity. On the other hand, the addition of iron oxide powders to coke was not effective. Substitution of small ratio of iron oxide powder for iron ore fines in the carbon iron ore composite with biomass char remarkably improved the reactivity of the composite.