| The thermoanalysis kinetic of calcium oxalate monohydrate were studied by means of TG-DTG techniques under non-isothermal conditions. The kinetic parameters and the most probable mechanism of the thermal dehydration process of calcium oxalate monohydrate were evaluated through analysis of the TG and DTG curves. The runs were performed in a flowing nitrogen atmosphere. The heating rates were different. Both model-free method method and model-fitting method were used to calculate the Arrhenius parameters and determine the most probable reaction mechanism in non-isothermal kinetics.The activation energy of the thermal dehydration process of calcium oxalate monohydrate could be got using model-free method. We also used model-fitting method to calculate the Arrhenius parameters and determine the reaction mechanism in non-isothermal kinetics. The kinetic parameters and the most probable mechanism of the reaction were evaluated through analysis of the TG and DTG curves by using combined differential and integral method. This method was simple and could get results quickly, but it forced fitting of experimental data to kinetic model. The result of this method were valuable to us.The activation energy of the thermal dehydration process of calcium oxalatem monohydrate could be got using Ozawa equation. The Arrhenius parameters and the most possible reaction mechanism function of the thermal dehydration process of calcium oxalate monohydrate could be got using Coats-Redfern equation and Achar equation. The analysis results show that the most possible reaction mechanism function of the thermal dehydration process of calcium oxalate monohydrate are as follows: G(a)=1-(1-α)1/2, f (α)=2(1-α)1/2, the kinetic equation of the thermal dehydration process of calcium oxalate monohydrate is as follows:Subsequently, the activation energy E is 112.48 kJ·mol-1 and the preexponential constant lnA is 22.64.
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