Effect of Nature Gas Injection on Reducibility ...

The main method for iron production is the blast furnace. It emits about 2 billion tons CO2 per year, which has the largest contribution in global warming. Using thermo-gravimetric technique, wustite samples prepared from Baharia iron ore sinter were isothermally reduced at 900-1100 oC by different ratios of H2/CO/CO2/N2 which is somewhat simulating the composition of the reducing gas in case of natural gas injection with low oxygen enrichment in the blast furnace. The reduction extent for wustite from iron ore sinter is clearly enhanced to be in the range of 54-69% comparatively with that reduced with coke gases (30-50%) as industrial data. Enhancement of wustite reducibility decreases the remaining quantity of unreduced wustite, which descends to high temperature region at which reduction depends mainly on solid carbon that will consequently lead to reduction of coke consumption and CO2 emission. The reduction rate of wustite samples is independent on either the reaction temperature or the H2 concentration in the reducing gas mixture due to the water gas shift reaction. The reduction rate of wustite samples at initial stages are most likely controlled by the combined effect of chemical reaction and gaseous diffusion mechanisms while at final stages are most likely controlled by interfacial chemical reaction mechanism.