{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,17]],"date-time":"2026-09-17T22:12:50Z","timestamp":1789683170004,"version":"4.0.1"},"reference-count":29,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2026,3,30]],"date-time":"2026-03-30T00:00:00Z","timestamp":1774828800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Key Scientific Research Project of the Hunan Provincial Department of Education","award":["23A0592"],"award-info":[{"award-number":["23A0592"]}]},{"name":"Innovation Training Program for College Students of Hunan University","award":["202210545005"],"award-info":[{"award-number":["202210545005"]}]},{"name":"Research Project of the Education Department of Hunan Province","award":["21C0717"],"award-info":[{"award-number":["21C0717"]}]},{"name":"The Hunan Provincial Student Innovation and Entrepreneurship Training Program"},{"name":"Nanling Characteristic Chinese medicine resources protection and utilization of the key laboratory in Hunan Province"},{"name":"Research and Development Center for Big Data Simulation Technology in the Prevention and Monitoring of Heavy Metal Ion Water Pollution in Chenzhou"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Materials"],"abstract":"<jats:p>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 \u03bcm. 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\u2014a 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.<\/jats:p>","DOI":"10.3390\/ma19071369","type":"journal-article","created":{"date-parts":[[2026,3,30]],"date-time":"2026-03-30T13:41:03Z","timestamp":1774878063000},"page":"1369","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Oxidation Behavior of Direct Reduced Iron Powder During Ball-Milling Treatment"],"prefix":"10.3390","volume":"19","author":[{"given":"Qiao","family":"Liu","sequence":"first","affiliation":[{"name":"Hunan Provincial Key Laboratory of Xiangnan Rare-Precious Metals Compounds and Applications, School of Chemistry and Environmental Science, Xiangnan University, Chenzhou 423000, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Zhikai","family":"Liang","sequence":"additional","affiliation":[{"name":"Hunan Provincial Key Laboratory of Xiangnan Rare-Precious Metals Compounds and Applications, School of Chemistry and Environmental Science, Xiangnan University, Chenzhou 423000, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Cheng","family":"Zhang","sequence":"additional","affiliation":[{"name":"Hunan Provincial Key Laboratory of Xiangnan Rare-Precious Metals Compounds and Applications, School of Chemistry and Environmental Science, Xiangnan University, Chenzhou 423000, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xinyu","family":"Fu","sequence":"additional","affiliation":[{"name":"Hunan Provincial Key Laboratory of Xiangnan Rare-Precious Metals Compounds and Applications, School of Chemistry and Environmental Science, Xiangnan University, Chenzhou 423000, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lingyun","family":"Yi","sequence":"additional","affiliation":[{"name":"School of Minerals Processing & Bioengineering, Central South University, Changsha 410083, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Zhucheng","family":"Huang","sequence":"additional","affiliation":[{"name":"School of Minerals Processing & Bioengineering, Central South University, Changsha 410083, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jiayuan","family":"Li","sequence":"additional","affiliation":[{"name":"Hunan Provincial Key Laboratory of Xiangnan Rare-Precious Metals Compounds and Applications, School of Chemistry and Environmental Science, Xiangnan University, Chenzhou 423000, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jun","family":"Chen","sequence":"additional","affiliation":[{"name":"Hunan Provincial Key Laboratory of Xiangnan Rare-Precious Metals Compounds and Applications, School of Chemistry and Environmental Science, Xiangnan University, Chenzhou 423000, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,3,30]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"361","DOI":"10.1080\/08827500903185208","article-title":"Strategies for processing low-grade iron ore minerals","volume":"30","author":"Srivastava","year":"2009","journal-title":"Miner. 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