Isolation and identification of the intermediate and final products in the thermal decomposition of dolomite in an atmosphere of carbon dioxide

Extensive studies have been done on the behavior of dolomite when subjected to a rising temperature program. In this study a literature survey was prepared related to the thermal decomposition of dolomite and the probable mechanisms proposed by various workers for the above reaction. Dolomite undergoes a two-stage decomposition in one atmosphere of carbon dioxide: while the same decomposition proceeds via a single step at lower partial pressures of carbon dioxide. The intermediate and final products for the two-stage decomposition of dolomite were isolated and identified using thermogravimetry and X-ray powder diffraction. On each of the isolated samples scanning electron microscopy was carried out. The intermediate products were found to be dolomite. calcite and periclase, while the final products were calcium oxide and periclase. Using these results a mechanism of thermal decomposition for dolomite is proposed. (C) 2001 Elsevier Science B.V. All rights reserved.