Kinetic analysis of isothermal decomposition of (Mg5(CO3)‎4(OH)‎2.4H2O5Cr2o3)‎ crystalline mixture

Abstract EN

Isothermal decomposition of the physical crystalline mixture of (Mg5 (C03) 4(OH) 2.

4H20 / 5Cr203) were studied in static air in the temperature range of (175- 450 °C).

Kinetics of decomposition were followed using both model-fitting and model-free approaches.

Analysis of the kinetic triplets (the mechanistic model, Ea and InA) showed that the decomposition behavior of crystalline mixture was best described by third-order reaction mechanism (F3) in the range of (175- 350 C) and one-dimensional diffusion reaction mechanism (D|) in the range of (375- 450 C).

Thermodynamic and kinetic values of the decomposition process were calculated and evaluated.

Analysis of data using model free approach signify the dependency of Ea on extent of conversion (a).

Pre-y-irradiation of the crystalline mixture with (102 and 103 kGy) y-ray doses has almost no significant effect on the kinetic parameters, the decomposition mechanisms and the solid phases which were followed by XRPD and FTIR measurements.