Reduction Kinectics of Hematite Powders in Non-Equilibrium Hydrogen Plasma

Abstract

The reduction kinetics of hematite (Fe2O3) powders was studied using nonequilibrium hydrogen plasma as reducing agent. Reduction experiments were performed in a DC pulsed plasma reactor, hydrogen flow-rate of 300 cm3/min, at pressure of 400 Pa, reduction times in range 30-120 minutes and in temperatures range 320-380 °C. Fe2O3 powders after reduction experiments were characterized by X-ray diffraction, weight loss of oxygen (gravimetric analyses), optic microscope and scanning electron microscope. The results showing that the reduction temperature of 380 °C after 120 min allows obtaining α-iron with a reduction fraction of about 0.93. The powder particles are transformed into two steps: Fe2O3→Fe3O4→Fe-α. The activation energy experimentally established for the reduction of Fe2O3 was about 98.4 kJ/mol.

Keywords

• Hematite reduction
• Hydrogen plasma
• Solid-state reaction
• Activation energy