On the kinetics of chromite reduction

Abstract

We reduced a natural chromite under controlled geometrical and thermodynamic conditions. The reaction between graphite and chromite in argon at 1200 and 1400°C is apparently rate-limited by a step that either involves the reductant or the gas phase. The reduction of chromite in an H₂-H₂O mixture at 1200°C follows the parabolic rate law; i.e., it is rate-limited by diffusion in the oxide.

Key Words:

• Spinel
• Chromite
• Reduction
• Reaction kinetics
• Parabolic rate law
• Solid-state diffusion