加热影响凹凸棒土结构的光谱分析

凹凸棒土含有四种羟基，3 614 cm-1处的吸收峰是与结构内部的四面体结构和八面体之间的Mg，Al相连羟基的伸缩振动;3 552和3 581 cm-1处的吸收峰是与凹凸棒土孔道边缘的Mg，Al八面体相连的结构水的羟基的对称和不对称伸缩振动;3 415 cm-1处的吸收峰是凹凸棒土中结晶水的羟基振动引起的;1 653 cm-1处的吸收峰是沸石水的吸收峰。将凹凸棒土在不同温度恒温30 min，通过不同的恒温温度各粉样的傅里叶红外光谱(FTIR)和X射线衍射光谱(XRD)的实测和比较，发现温度较低时结构内部的沸石水、结晶水、结构水同时减少;经450 ℃恒温30 min后，结构水被除去，凹凸棒土的晶体结构开始改变;结构羟基非常稳定，600 ℃恒温才会被破坏。文章初步探讨了热处理过程中化学变化过程。

Spectra Study on the Influence of Drying Process on Palygorskite Structure

There are four different types of molecules of hydroxyl groups of the natural attapulgite. The band at 3614 cm(-1) was attributed to the stretching modes of hydroxyls coordinated with the magnesium. The band at 3415 cm(-1) is associated with the hydroxyl stretching vibrations of absorbed water. The bands at 3581 and 3552 cm(-1) were attributed to the symmetric and antisymmetric stretching modes of molecular water coordinated with the magnesium at the edges of the channels. The band at 1653 cm(-1) is associated with the hydroxyl stretching vibrations of zeolitic water. The structures of the natural palygorskite and its products dried at different temperatures for 30 min were analysed by Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The absorbed, zeolitic and co-ordinated water decreased during the drying process at the same time. The absorbed water was completely-dehydrated firstly, then the zeolitic water, and lastly the co-ordinated water. And the hydroxyl groups remained until about 600 degrees C. When the co-ordinated water was dehydrated completely at 450 degrees C, the crystalloid was destroyed. The mechanism of the palygorskite structure change was also discussed in detail.