Solid State Reduction of Hematite Ore Using Hydrogen at Moderate Temperatures

This work is carried out to investigate the reduction of hematite ore fines in a pure hydrogen atmosphere using thermogravimetric analysis (TGA). The effect of temperature (973-1173K) and hydrogen flow rate (1–2.5 L per minute) on the reduction kinetics was examined. The phases, morphological features, and chemical composition of hematite ore were identified using X-ray diffraction (XRD), Scanning electron microscopy (SEM), and X-ray fluorescence (XRF), respectively. The reduction kinetics were investigated using global reduction methods. The results show that the rate of reduction increases with temperature. An increase in hydrogen flow rate after the critical flow rate 2.5 LPM does not affect the rate of reduction. For global reduction, the reduction kinetics analysis indicates that the reduction was controlled by chemical mechanism. The apparent activation energy and preexponential factor for the global step are 20.4137 ± .22 kJ/mol and 0.7202 respectively.