偏高岭石的微观结构与键合反应能力

STUDY OF THE MICROSTRUCTURE OF METAKAOLINITE WITH IR, TG, SEM, XRD METHODS

对450～1050℃下热变高岭石结构,尤其是偏高岭石结构进行了研究。针对晶体高岭石和非晶体偏高岭石的结构特征,采用了XRD、SEM和IR等测试技术手段进行矿物组成和结构分析。采用热重GT测试方法对高岭石的热分解过程进行了研究,通过对矿物化学键合材料强度试验来表征偏高岭石的反应活性。结果发现:偏高岭石中的铝氧层是化学键合反应能力的敏感结构单元,IR谱中表征Al—O键共振的817cm-1吸收峰与其化学键合反应能力相关联,存在该吸收峰的热变高岭石具有化学键合反应能力,相对吸收率越大,化学键合反应能力越高。

This paper deals with the microstructure of kaolin heated at 450—1050 ℃ on the geopolymic activity of metakaolinite. The samples of raw kaolin (K0) and metakaolinite were tested by X-ray diffraction (XRD), scanning electron microscopy (SEM) and infrared spectroscopy (IR) in order to reveal their mineral composition and structural differences. The decomposition of kaolinite was recorded using the methods of the thermogravimetric analysis (TG). The activity of the thermally treated samples was evaluated based on the compressive strength of geopolymers. It is concluded that the geopolymic activity of metakaolinite is strongly related to the Al-O polyhedral layers of the metakaolinite. Well-ordered kaolinite was transformed into less active metakaolinite. he appearance of a band at 817 cm^(-1) would be connected with the change of AlO bands in metakaolinite and related with the geopolymic activity of metakaolinite. The geopolymic activity of metakaolinite increased with increasing band at 817 cm^(-1).