Related Experiment Video
Updated: Apr 15, 2026

Author Spotlight: Magnetometric Characterization of Intermediates in the Solid-State Electrochemistry of Redox-Active Metal-Organic Frameworks
Published on: June 9, 2023
Oxidation Behavior of Direct Reduced Iron Powder During Ball-Milling Treatment
Qiao Liu1, Zhikai Liang1, Cheng Zhang1
1Hunan Provincial Key Laboratory of Xiangnan Rare-Precious Metals Compounds and Applications, School of Chemistry and Environmental Science, Xiangnan University, Chenzhou 423000, China.
Abstract:
High-quality direct reduced iron (DRI) powder is essential for applications in catalysis, adsorption, and electromagnetic materials. However, its tendency to reoxidize during processing presents a significant challenge. This study investigates the oxidation behavior of DRI powder during wet ball-milling treatment. Samples were characterized using chemical phase dissolution, X-ray diffraction (XRD), scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS), and X-ray photoelectron spectroscopy (XPS) to assess both bulk and surface oxidation. The results reveal that significant oxidation occurs during the wet grinding and subsequent processing stages, with the relative oxidation degree (ROD) of the iron powder increasing sharply from 6.08% to 26.81% as the grinding time is extended from 20 to 40 min. SEM-EDS analysis indicates that oxidation is particularly pronounced in particles smaller than 10 μm. XRD confirms the gradual transformation of Fe0 to Fe3O4 with prolonged grinding, corroborating the chemical analysis. Furthermore, XPS analysis of the Fe 2p, Fe 3p, Fe 3s, and O 1s core levels reveals that the nanoscale surface is composed of Fe2O3, Fe3O4, Fe(OH)3, and FeOOH-a composition distinctly different from the bulk Fe/Fe3O4 phases. These findings underscore the critical roles of particle size and mechanical activation in driving DRI reoxidation during wet milling.
Related Concept Videos
Redox Reactions
Oxidation of Phenols to Quinones
o-hydroxy phenols are oxidized to o-quinones and p-hydroxy phenols to p-quinones. Such redox reactions involve the transfer of two electrons and two protons. The reversible redox...
Redox Titration: Other Oxidizing and Reducing Agents
Radical Oxidation of Allylic and Benzylic Alcohols
Corrosion
Microbes and Other Elemental Cycles

