Large amounts of injectants are used in the blast furnace (BF) process to reduce coke consumption, but this changes the gas composition in the BF shaft where iron ore reduction takes place. H
2 and H
2O gases change markedly in the gas atmosphere at high injection levels, which makes it important to investigate their effects on the reduction of iron oxides in a CO–CO
2 atmosphere. The gaseous H
2 and H
2O content in the BF shaft atmosphere is approximately 8%. In the present work olivine pellets were reduced in H
2–H
2O–CO–CO
2 and CO–CO
2 atmospheres with equal reducing potentials of H
2 and CO by fixing the H
2/H
2O and CO/CO
2 ratios. No significant differences in the reduction rates of iron oxides were found between the H
2–H
2O–CO–CO
2 and CO–CO
2 atmospheres at high temperatures but at lower temperatures H
2–H
2O–CO–CO
2 had higher reduction rate. Activation energies determined for hematite to magnetite reduction for both gas mixtures indicated better initial stage and later stage reduction in the H
2–H
2O–CO–CO
2 atmosphere. Field Emission Scanning Electron Microscope (FESEM) analysis was carried out on samples, and wüstite relics were found in the inner parts of pellets reduced to iron in the CO–CO
2 gas but not in the samples reduced in the H
2–H
2O–CO–CO
2 gas.
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