(1. 中南大學(xué) 冶金與環(huán)境學(xué)院，長(zhǎng)沙 410083；
2. 中南大學(xué) 國(guó)家重金屬污染防治工程技術(shù)研究中心，長(zhǎng)沙 410083)
摘 要: 通過(guò)TG、物相分析、XPS、XRD、SEM-EDS等手段研究鐵酸鋅選擇性還原反應(yīng)機(jī)理，考察鐵酸鋅質(zhì)量損失和分解特征、物相轉(zhuǎn)變過(guò)程和產(chǎn)物層形貌變化以及Zn2+與Fe2+的離子遷移行為。結(jié)果表明：反應(yīng)表現(xiàn)為失氧過(guò)程，還原產(chǎn)生的Fe2+使鐵酸鋅分解產(chǎn)生ZnO，ZnO含量與Fe2+含量線性相關(guān)。Fe2+向鐵酸鋅內(nèi)部遷移替代Zn2+，Zn2+則向外部遷移并富集于表面，促使ZnO在表面形成。鐵酸鋅逐步向磁鐵礦轉(zhuǎn)變，F(xiàn)e2+的嵌入和鋅的遷出使鐵酸鋅晶胞參數(shù)先增大后減小，還原產(chǎn)物為ZnO和含鋅的磁鐵礦。顆粒產(chǎn)物層中的還原產(chǎn)物相互夾雜，并包裹著未反應(yīng)的鐵酸鋅。
關(guān)鍵字: 鐵酸鋅；選擇性還原；相變過(guò)程；離子遷移
（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
