Fourier-transform Infrared Emission Spectroscopy of Kaolinite Dehydroxylation

Abstract

The dehydroxylation of kaolinite has been investigated by Fourier-transform in situ IR emission spectroscopy from 100 to 800°C at 5 degree intervals. The major advantage lies in the ability to obtain vibrational spectroscopic information in situ at the elevated temp. Dehydroxylation was detd. by the loss of intensity of the hydroxyl bands in the 3550-3750 cm-1 emission spectra. No clay phase changes occur until after dehydroxylation takes place. The kaolinite layers lose their outer and inner hydroxyl groups simultaneously. It is proposed that the kaolinite dehydroxylation process takes place homogeneously and involves two mechanisms. [on SciFinder(R)]