Study on the ion behavior of solid-phase reaction synthesis of iron chromite at 1473 K

• The self-diffusion coefficient of Fe ions is consistently higher than that of Cr ions during solid-phase synthesis of iron chromite at 1473 K. • The activation energy for the formation of Fe(CrxFe1−x)2O4 spinel is 177.20 kJ·mol−1, with a pre-exponential factor of 610.78 min−1. • The diffusion couple method effectively reveals the diffusion and solid solution behavior of Fe2+, Cr3+, and Fe3+ ions in the reaction. • The findings provide kinetic parameters essential for optimizing chromium recovery from stainless-steel pickling sludge via pyrometallurgical processes.