碳热还原制备镁铝尖晶石晶须及其形成机理  

Preparation and Formation Mechanism of Magnesium Aluminate Spinel Whiskers by Carbothermal Reduction Method

作　　者：张彦祥 李红霞[1] 杨文刚[1] 刘国齐[1] 张利萍[1] 田响宇 尚心莲 ZHANG Yanxiang;LI Hongxia;YANG Wengang;LIU Guoqi;ZHANG Liping;TIAN Xiangyu;SHANG Xinlian(State Key Laboratory of Advanced Refractories,Sinosteel Luoyang Institute of Refractories Research Co., Ltd.,Luoyang 471039)

机构地区：[1]中钢集团洛阳耐火材料研究院有限公司,先进耐火材料国家重点实验室,洛阳471039

出　　处：《材料导报》2018年第8期1352-1356,共5页Materials Reports

基　　金：国家自然科学基金(51372231;51772277);河南省科技创新人才计划(164100510023);河南省基础与前沿研究项目(162300410057)

摘　　要：为制备镁铝尖晶石晶须及探究其生成机理,采用电熔镁砂、活性α-Al_2O_3和石墨为主要原料,在埋碳气氛1 550℃烧制3h合成纤维状镁铝尖晶石晶须,分别使用X射线衍射(XRD)、扫描电子显微镜(SEM)和能量色散光谱(EDS)对产物的物相、形貌和物微区化学成分进行观察分析。结果表明:晶须物相组成为镁铝尖晶石;镁铝尖晶石晶须顶端尖锐,部分晶须有分叉现象,长度可达10mm,直径约为5~20μm;当Al_2O_3与C共存时,镁铝尖晶石晶须生成量较多;镁铝尖晶石晶须的原位生长遵循气-固(VS)机制。Aiming at investigating the preparation and formation mechanism of magnesium aluminate spinel whisker,the present work utilized fused magnesia(≤0.074 mm),α-Al 2O 3(d 50=2.5μm)and flake graphite(≤0.15 mm)as main raw materials and applied a carbon-embedded heat-treatment process at 1 550℃for 3 h to synthesize fibroid whisker-like MgAl 2O 4,whose phase composition and microstructure were characterized by X-ray diffraction(XRD),scanning electron microscope(SEM),and energy dispersive X-ray spectroscopy(EDS),respectively.The results confirmed the spinel phase of the resultant whiskers with the length of up to 10 mm and an average diameter ranging from 5μm to 20μm.The spinel whiskers exhibit sharp terminals,and some of the whiskers have branches.The mutual presence of alumina and graphite can lead to a relatively large amount of spinel whiskers.It can also be concluded that the vapor-solid(V-S)mechanism dominates the in-situ growth of the magnesium aluminate spinel whiskers.

关 键 词：镁铝尖晶石晶须 碳热还原 生长机制 

分 类 号：TQ17[化学工程—硅酸盐工业]