吉林长白山硅藻土的红外光谱研究

对长白山硅藻土在 10 0～ 1330℃温度范围进行热处理并开展红外光谱研究 ,结果表明经 5 0 0℃热处理样品开始出现 374 5cm- 1 峰 ,在 90 0℃达到最大 ,12 0 0℃消失 ,此时硅藻土转变成方石英。对 374 5cm- 1 峰所反映的以孤立Si—OH形式存在的水的含量进行了半定量计算 ,表明这种OH除存在于样品表面外 ,还存在于内部的结构缺陷处 ,并推测硅藻土转变成方石英与这种孤立Si—OH的消失有关

Infrared Spectroscopic Study of Changbaishan Diatomite

Changbaishan diatomite was treated under the conditions of temperature from 100 to 1330 degrees C, and examined by infrared spectroscopy applying the KBr-technique. In the range from 250 to 1500 cm(-1), the spectra of the samples at 100 to 1100 degrees C show the same three characteristic broad bands at 1100, 801 and 471 cm(-1), which are similar to amorphous silica. Besides the above three broad bands, the spectra of 1200 and 1330 degrees C treated samples exhibit three new bands at 618, 386 and 301 cm(-1), which indicate that the diatornite transforms into cristobalite. While all of the eleven samples show an asymmetric broad band at 3440 cm(-1) in the range from 3000 to 4000 cm(-1), the spectrum of 500 degrees C treated sample begins to exhibit a 3745 cm(-1) band assigning to isolated Si-OH group stretching vibration. The 3745 cm(-1) band shows the highest intensity at 900 degrees C, and disappears at 1200 degrees C. According to the absorbance of the 3745 cm(-1) band of different temperature treated samples, the H2O content in the form of Si-OH group was calculated semi-quantitatively, which indicates that the Si-OH group exists at the internal structure defects in addition to existing at the surface. The transform mechanism of diatomite into cristobalite was also discussed.