Predehydroxylation State of Kaolinite

Abstract

THE loss of water of constitution from kaolinite with increasing temperature under atmospheric pressure is illustrated in Fig. 1. This loss is very low, up to about 450° C., where it increases very rapidly. The infra-red spectrum of an unheated sample shows a hydroxyl vibration band about equally divided into three transmission minima the frequencies of which are located respectively at 3,700 cm.⁻¹, 3,663 cm.⁻¹ and 3,627 cm.⁻¹.