变高岭石的结构研究

STRUCTURE OF METAKAOLINITE

变高岭石是高岭石的加热相变产物 .用广角度X射线衍射散射 (WAXS)和由它得到的径向分布函数 (RDF)研究了变高岭石结构表明 :它是一种含有少量结晶相或沿c轴失序的半晶物质 ,其结晶度随热处理温度而变化 .构成变高岭石的结构单元是四面体 [MO4] (M =Si,Al)和八面体 [AlO6 ] .变高岭石结构中近邻四面体与四面体、四面体与八面体是共顶连接的 ,而近邻八面体与八面体是共面连接的 .变高岭石的近程结构将不随结晶性或序性变化 .它的微结构及其随热处理温度的变化主要决定于结构基元之间的关系和序性 .

Metakaolinite is a phase_changed substance obtained through heating kaolinite. The research on the structure of metakaolinite by using wide_angle X -ray diffraction_scattering technology(WAXS) and its radial distribution function(RDF) shows that metakaolinite is a hemicrystal which is disordered in c -axle and composed of non_crystalline phase and a little crystalline phase. The crystallinity is changed with heating temperature. The structure unites are tetrahedral [MO 4](M=Si,Al) and octahedral [AlO 6]. The adjacent tetrahedral-tetrahedral and tetrahedral-octahedral in metakaolinite are co_apical linkage, but the octahedral-octahedral are coplanar linkage. The short_range structure of metakaolinite is not changed with its crystallinity or ordered degree. The microstructure of metakaolinite and its changes with heating temperature are mainly depended on the relationship between the structure unites and ordered degree in metakaolinite.