FOURIER-TRANSFORM INFRARED-EMISSION SPECTROSCOPY OF KAOLINITE DEHYDROXYLATION

The dehydroxylation of kaolinite has been investigated by Fourier-tran sform in situ infrared emission spectroscopy from 100 to 800 degrees C at 5 degree intervals. The major advantage lies in the ability to obt ain vibrational spectroscopic information in situ at the elevated temp erature. Dehydroxylation was determined by the loss of intensity of th e hydroxyl bands in the 3550-3750 cm(-1) emission spectra. No clay pha se changes occur until after dehydroxylation takes place. The kaolinit e layers lose their outer and inner hydroxyl groups simultaneously. It is proposed that the kaolinite dehydroxylation process takes place ho mogeneously and involves two mechanisms.