FeNb_2O_6与硅铁界面反应行为的原位研究  

In-situ Investigation on the Interfacial Reaction Behavior of FeNb_2O_6 with Ferrosilicon

作　　者：闫鑫 赵增武 郭文涛 YAN Xin;ZHAO Zengwu;GUO Wentao(Key Laboratory of Integrated Exploitation of Bayan Obo Multi-metal Resources, Inner MongoliaUniversity of Science and Technology, Baotou 014010, China)

机构地区：[1]内蒙古科技大学内蒙古自治区白云鄂博矿多金属资源综合利用重点实验室,内蒙古包头014010

出　　处：《有色金属工程》2019年第5期58-63,共6页Nonferrous Metals Engineering

基　　金：国家自然科学基金资助项目(51464040;51464039);内蒙古自治区重大基础研究开放课题项目(20140201);包头市科技计划项目(2017Z1009-2);钢铁冶金新技术国家重点实验室开放基金项目(KF17-01)~~

摘　　要：白云鄂博矿中铌的主要存在形式之一是铌铁矿(FeNb_2O_6)。为了揭示FeNb_2O_6硅热还原机理,采用高温激光共聚焦显微镜(CSLM)在1 100℃和1 150℃下原位观察硅铁和FeNb_2O_6的界面反应行为,结合X射线衍射仪(XRD)、扫描电子显微镜—能谱仪(SEM-EDS)对还原后样品的相组成和微观结构进行分析。结果表明,硅热还原产物为NbO_2、Fe和SiO_2。相比1 100℃,1 150℃下FeNb_2O_6的硅热反应在更短的时间内(1min)开始发生。界面反应区分为两层,靠近硅铁的反应层主要由大量的SiO_2和FeSi_2,少量NbO_2组成;靠近FeNb_2O_6的反应层主要由大量的FeSi_2和NbO_2组成。FeSi_2作为Si的传输媒介,把Si运送到反应区。温度越高,越有利于硅热还原的进行。Columbite (FeNb 2O 6) is one of the main existing forms of niobium in Bayan Obo ore. In order to reveal the silicothermic reduction mechanism of FeNb 2O 6, the interfacial reduction behavior of ferrosilicon and FeNb 2O 6 was observed in situ by confocal scanning laser microscope (CSLM) at 1 100 and 1 150 ℃.The phase compositions and microstructure of the reduced samples were investigated by X ray diffraction (XRD) and scanning electron microscope - energy dispersive spectroscopy (SEM-EDS) analysis. The experimental results show that the reduction products were NbO 2, Fe, and SiO 2. Compare to 1 100 ℃, the silicothermic reduction of FeNb 2O 6 at 1 150℃ can initiate in a shorter time (1 min).The reaction zone can be divided into two reaction layers. The layer close to ferrosilicon was mainly composed of a large amount of SiO 2 and FeSi 2 and a small amount of NbO 2. The layer close to FeNb 2O 6 was mainly composed of a large amount of FeSi 2 and NbO 2. The FeSi 2 can act as a transfer medium for Si from ferrosilicon to the reaction zone. The higher temperature, the more conductive to the silicothermic reduction of silicon.

关 键 词：FeNb2O6 硅热还原 原位观察 界面反应 

分 类 号：TF841.6[冶金工程—有色金属冶金]