the layered reduction of hematite (iron oxide) ore by non-coking coal: the effect of calcium carbonate on reduction

due to the abundance of the non-coking coal and limitations as well as the high costs of the natural gas, the presentstudy examined the direct reduction of hematite (iron oxide) ore in the temperature range of 800-1000 °c by thenon-coking coal volatiles. approximately, 74.9% of the total amounts of volatiles and gases exit the coal up to800°c. the onset temperature to exit volatiles from the non-coking coal was approximately 525°c. the semmicrographs and xrd results indicated the non-uniform layered reduction of the hematite layer. as temperaturewas increased, the reduction of hematite ore was increased. at a constant temperature of 1000°c, the reductionrate of the hematite layer reached a maximum after 30 min and then it was decreased. adding various amountsof calcium carbonate to the non-coking coal in optimal reduction conditions increased the reduction rate of thehematite ore. the optimal concentration of this catalyst was 5 wt% (relative to the coal).