ISSN print edition: 0366-6352
ISSN electronic edition: 1336-9075
Registr. No.: MK SR 9/7
Measurement of kinetics of thermal decomposition of calcium carbonate by a thermobalance with a quartz spiral and optical recording
Slovak Academy of Sciences,
Abstract: The measurement of the kinetics of thermal decompn. of CaCO3 in a vacuum or at zero CO2 partial pressure at 654°-756° by a thermobalance with a quartz spiral and optical recording is described. About 6 mg. pptd. CaCO3 was heated and then activated by decompn. at 700° in a vacuum and by recarbonization at 650° and at a pressure of 50 torr CO2. The detd. value of the formal order of the decompn. is close to 2/3 at all temps. so that the calcd. activation energy E = 42,000 ± 1100 cal. corresponds to the process in the phase boundary. It was detd. by the calcn. that the value E is equal to the activation energy of the thermal dissocn. of CaCO3 if the model occurrence takes into consideration all assumed reactions in the phase boundary. This value was used in the calcn. of the relation of the surface molar breakdowns of the active CaO and CaCO3 (α = 10-5), of the values of velocity consts. of the partial reactions in the phase boundary, and of the size of the effective surface of the sample (∼700 cm.2/g.). The value of the surface molar breakdown of the active CaO is changed very little in the equil. system CaO-CO2 between 650° to 850°, but at the const. temp. it is dependent on the partial pressure of CO2.
Full paper in Portable Document Format: 2010a697.pdf (in Slovak)
Chemical Papers 20 (10) 697–715 (1966)