(上海大学 上海市现代冶金与材料制备重点实验室，上海 200072)
摘 要: 采用热重分析、X射线衍射、扫描电镜和光学显微镜等技术对攀枝花预氧化钛精矿的H2还原行为进行研究，包括H2还原反应的动力学、还原产物的物相转变及显微结构的变化规律。结果表明：预氧化钛精矿在1 100 ℃还原80 min后还原度达到96.04%；在温度为1 000 ~1 150 ℃范围内，还原过程受界面化学反应控制，表观活化能为95.25 kJ/mol。在还原过程中将会形成M3O5型(M=Ti, Fe, Mg等)固溶体，导致还原难度加大。显微结构表明，还原反应由颗粒边缘向内部进行，而Mg元素在未反应内核的富集阻碍了预氧化钛精矿的进一步还原。
关键字: 预氧化钛精矿；H2；还原；动力学；物相；显微结构
（Shanghai Key Laboratory of Modern Metallurgy and Materials Processing, Shanghai University, Shanghai 200072, China）
Abstract:Reduction behavior of Panzhihua pre-oxidized ilmenite in hydrogen atmospheres, such as reduction kinetic, phase transformation and microstructures of reduced products was investigated by thermo-gravimetric，X-ray diffractometry (XRD), scanning electron microscopy (SEM), and optical microscopy. The results show that the reduction degree reaches 96.04% when the pre-oxidized ilmenite concentrates are reduced at 1 100 ℃ for 80 min and the reduction reaction is controlled by interfacial chemical reaction with the activation energy of 95.25 kJ/mol at 1 000-1 150 ℃. The M3O5 (M is Fe, Ti, Mg, etc) solid solution forms in the reduction process, in which the reduction difficulty increases. Microstructure analysis shows that the reaction takes place from the exterior of the grain to its interior and the enrichment of Mg in the unreacted area restricts the further reduction of pre-oxidized ilmenite.
Key words: pre-oxidized ilmenite; hydrogen; reduction; kinetics; phase; microstructure
