Utilization of Ores with High Combined Water Content for Ore-carbon Composite and Iron Coke

Reduction of CO2 emissions and effective use of low-grade iron resources are very important tasks for the steel industry. One of the methods to simultaneously achieve both is to lower the thermal reserve zone temperature in the blast furnace using a high-reactivity agglomerate such as an iron ore-carbon composite or iron coke in which the iron source is an ore with high combined water content. In this study, using high water content ores, the effects of the ore particle size and coal-ore mixture ratio in a composite on the reduction behavior were investigated. The impact of the ore particle size in iron coke on the gasification behavior was also investigated. A decrease in the ore particle size in the composite and an increase in the coal-ore mixture ratio lowered the temperature at which metallic iron starts to form. However, compared with hematite ore, weaker particle size and mixture ratio dependencies were obtained for composites made from ore having high combined water content. The utilization of an ore with high combined water content as the iron source is an effective method for lowering the temperature at which the gasification of iron coke begins. This temperature is about 20 K and 50 K lower than that when using coke with hematite ore and using coke only, respectively.