煤矸石在热活化过程中的相组成和结构变化

Changes in Minerial Composition and Structure of Coal Gangue During Heat Activation

在分析研究煤矸石化学与矿物组成的基础上,利用XRD、IR、NMR等手段研究了煤矸石在热活化过程中的结构渐变过程,结果表明,当温度从500℃升高至700℃时,煤矸石中的煤发生燃烧、高岭石结构逐渐向偏高岭石转变,至900℃时,偏高岭石的结构已完全破坏,并于1100℃时,形成了莫来石。指出煤矸石中高岭石转变为偏高岭石的模式为:随羟基的不断脱除,高岭石结构中部分Al原子的配位方式由六配位经五配位转变为四配位,而[SiO4]4-四面体聚合状态仍保持Q3结构。

The changes in composition and structure of coal gangue during heat and mechanical activation were investigated by means of XRD, IR and nuclear magnetic resonance （NMR）. The results show that during calcining process of coal gangue, coal in the coal gangue burned, kaolinite gradually transformed into metakaolin when calcining temperature raised from 500℃ to 700℃. When calcining temperature was up to 900℃, the structure of metakaolin was destroyed absolutely and mullite was formed at 1100℃. According to these experimental results, the model of the kaolinite structure change was founded through analyses and conclusion of the transformation of kaolinite structure during calcining process of coal gangue. The process is as follows： with hydroxyl gradually drew off, among structure of metakaolin, coordinate type of aluminum atoms transformed from hexa-coordinate to tetra-coordinate, while the ESiO4-]^4- tetrahedron polymerization state remained Q^3 type.