Preparation and dehydration behaviour of thomsonite with ideal chemical composition

Thomsonite with ideal chemical composition and with an ordered framework structure was synthesised hydrothermally from zeolite Na−A, which was ground to X-ray amorphous, with 0.05 mol dm−3 CaCl2 solution at 200°C. The dehydration behaviour of the prepared thomsonite was examined by TG-DTA. It was revealed that thomsonite lost most of zeolitic water below 450°C in three steps at about 180°, 340° and 390°C. The peak profiles of, the two higher-temperature endotherms were sharp and similar, and the weight loss at each step was approximately equal.