Effect of gas composition on reduction behavior in red mud and iron ore pellets

In this study, mass loss and direct reduction characteristics of red mud and iron ore pellets in different atmosphere and temperature was investigated. The reaction kinetics parameters were estimated based on the experiments and different model equations. In addition, the phase transformation and microstructure of the reduction process were studied by X-ray diffraction technique (XRD) and Scanning electron microscope (SEM). The results show that the reduction process is three-dimensional phase-boundary controlled in H-2 and CO atmosphere. The rate of reduction in the presence of H-2 is significantly higher than in the CO atmosphere above 900 degrees C. 1100 degrees C and hydrogen atmosphere is optimum for the reduction of both iron ore concentrate and red mud pellets in the experimental conditions. (C) 2016 Published by Elsevier B.V.