Kinetics of the Thermal Decomposition of Mg-Al Sulfate Hydrate

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J. Korean Ceram. Soc. > Volume 24(5); 1987 > Article

Journal of the Korean Ceramic Society 1987;24(5): 417.

Mg-Al 복합 황산염 수화물의 열분해 속도

박홍채, 오기동

부산대학교 무기재료공학과

Kinetics of the Thermal Decomposition of Mg-Al Sulfate Hydrate

ABSTRACT

Kinetic studies were made on the thermal decomposition of hydrated magnesium aluminum double sulfate by a nonisothermal TG method. Thermal analyses of the dehydration of tricosahydrate showed that the reaction proceeded via decahydrate to the anhydrous MgAl2(SO4)4 in the range 50$^{circ}$to 400$^{circ}C$. Decomposition of MgAl2(SO4)4 occurred as the two-step between 650$^{circ}$ and 970$^{circ}C$. Dehydration of MgAl2(SO4)4$.$23H2O and a 2D diffusion controlled with an activation energy of 16.6kcal/mole, respectively. MgAl2(SO4)4 fitted the contracting volume model with an activation energy of 10.5kcal/mole, and MgSO4 fitted a contracting area model with an activation of 4.5kcal/mole.