An Investigation of the Decomposition Mechanism of Calcium Carbonate

D. Wang, S. Zhang, Q. Wang. School of Materials and Metallurgy, University of Science and Technology Liaoning, China Z. Zhao. School of Chemistry and Life Science, Anshan Normal University, Liaoning, China G.L. Tan. Department of Chemical Engineering, Yingkou Institute of Technology, Liaoning, China This paper focuses on investigating the decomposition mechanism of ca lcium carbonate. The non-isothermal thermal decompositions of calcium carbonate under vacuum and flowing nitrogen atmosphere have been studied by thermogravimetric analysis. With the application of the advanced nonlinear isoconversional method, the determined activation energy for each condition is dependent on the extent of reaction. Based on the dependences, a process involving two consecutive decomposition steps has been simulated. The simulation results match the experimental results of flowing nitrogen atmosphere. Results indicate that the decomposition of calcium carbonate undergoes the process of the formation of the intermediate and metastable product.