Chromite Pellet Prereduction by Methane‐Containing Gas: Influence Factors and Consolidation Mechanism

Prereduction process of chromite is an effective method for saving energy and reducing emissions during ferrochrome alloy production. This study investigates the factors affecting the reduction and strength levels of chromite pellets reduced in a CH 4 –H 2 atmosphere. Thermodynamic calculations indicate that carbon from methane pyrolysis is highly active, and chromium oxide can be converted to metal chromium and carbide at lower temperature of 1100 °C. The experimental results show that extending the reduction time can increase the pellet metallization rate without sacrificing strength at 1100 °C in 10% CH 4 . As the reaction progressed, the carbon from methane cracking diffused into the pellet through the metallic iron, creating observable diffusion channels. Continuous methane input further facilitates this mechanism, leading to iron carbide precipitation and ultimately compromising the pellet strength. The consolidation mechanism of pellets in CH 4 –H 2 = 10:90 atmosphere is analyzed using X‐ray diffraction, scanning electron microscopy‐energy dispersive X‐ray spectroscopy, and chemical analysis. The consolidation process of the pellets can be divided into four stages—namely, liquid phase formation, phase transition, strengthening, and carbonization stages.