On Crystallization of Hadong Kaolin Granulated Cylindrically Treated with Aqueous Sodium Hydroxide Solution

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J. Korean Ceram. Soc. > Volume 15(1); 1978 > Article

Journal of the Korean Ceramic Society 1978;15(1): 21.

원주형으로 성형된 하동고령토의 수산화나트륨 수용액 처리에 의한 결정의 변화

김면섭

한양대 공대 화공과

On Crystallization of Hadong Kaolin Granulated Cylindrically Treated with Aqueous Sodium Hydroxide Solution

ABSTRACT

Hadong Kaolin (Halloysite) was granulated cylindrically and treated with 1N aqueous sodium hydroxide solution for 6-48 hrs at 60-10$0^{circ}C$. The crystalling structure of surface of the products was studied by X-ray powder diffraction method. The reaction rate of halloysite to sodium A zeolite showed a gradual decrease from surface to inner layer. At the surface layer, the reaction mechanism was observed as first order consecutive reaction as follows: halloysitelongrightarrowamorphous aluminosilicatelongrightarrowsodium A zeolitelongrightarrowhydroxysodalite By applying the above reaction mechanism, the rate constants and activation energies was measured.