(1. 中南大学 冶金与环境学院，长沙 410083；
2. 中南大学 国家重金属污染防治工程技术研究中心，长沙 410083)
摘 要: 通过TG、物相分析、XPS、XRD、SEM-EDS等手段研究铁酸锌选择性还原反应机理，考察铁酸锌质量损失和分解特征、物相转变过程和产物层形貌变化以及Zn2+与Fe2+的离子迁移行为。结果表明：反应表现为失氧过程，还原产生的Fe2+使铁酸锌分解产生ZnO，ZnO含量与Fe2+含量线性相关。Fe2+向铁酸锌内部迁移替代Zn2+，Zn2+则向外部迁移并富集于表面，促使ZnO在表面形成。铁酸锌逐步向磁铁矿转变，Fe2+的嵌入和锌的迁出使铁酸锌晶胞参数先增大后减小，还原产物为ZnO和含锌的磁铁矿。颗粒产物层中的还原产物相互夹杂，并包裹着未反应的铁酸锌。
关键字: 铁酸锌；选择性还原；相变过程；离子迁移
（1. School of Metallurgy and Environment, Central South University, Changsha 410083, China;
2. Chinese National Engineering Research Center for Control and Treatment of Heavy Metal Pollution,
Central South University, Changsha 410083, China）
Abstract:The selective reduction mechanism of zinc ferrite was studied by TG, phase analysis, XPS, XRD and SEM-EDS. The mass loss, decomposition features of zinc ferrite, ionic migration behavior of Zn2+ and Fe2+ ions, phase transformation process and morphological change of product layer were investigated. The results show that reaction is oxygen loss process. The reduced Fe2+ made ZnO separated from zinc ferrite, the content of ZnO has a significant linear correlation with the content of Fe2+. Fe2+ migrates into the inner zinc ferrite to substitute Zn2+, while Zn2+ moves out and enriches on the surface, promoting the formation of ZnO. Zinc ferrite transforms to magnetite, the lattice parameter of zinc ferrite increases and then decreases due to the intercalation of Fe2+ and the emigration of Zn2+. The reduction products are zinc oxide and zinc-containing magnetite. The reduction products coexist with each other in the product layer and unreacted zinc ferrite is covered with the product layer.
Key words: zinc ferrite; selective reduction; phase transformation; ionic migration
