The Ion-Exchange Properties of Synthetic Zeolite A from Domestic Kaolin

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J. Korean Ceram. Soc. > Volume 18(2); 1981 > Article

Journal of the Korean Ceramic Society 1981;18(2): 91.

국산 고령토로 합성한 제올라이트 A의 이온교환성

김영대, 김면섭

한양대학교 화학공학과

The Ion-Exchange Properties of Synthetic Zeolite A from Domestic Kaolin

ABSTRACT

Synthetic zeolite A was prerared from domestic Hadong kaolin with sodium hydroxide solution and their ion exchange isotherms of $K^+$, $NH^{4+}$, $Li^+$ and $Ag^+$ ion were presented. The optimum reaction conditions for synthetic zeolite A from calcinated kaolin were 2 fold excess of 2N sodium hydroxide solution, 10$0^{circ}C$ and 8 hours. It was observed that before the crystallization of zeolite A the samples reacted with sodium hydroxide solution had rather higher ion exchange capacities than zeolite A. The $K^+$-$Na^+$ and $Ag^+$$Na^+$ ion exchange isotherms were signoidal. The initial selectivity series was in the order $Ag^+$$K^+$>$Na^+$>$NH_4$>$Li^+$. Between approximately 33 and 67% replacement of soium ions the selectivity series became $Na^>$ and above 67% became $Ag^+$>$K^+$. Evidence were also presented to demonstrate that 8 out of 12 sodium ions per pseudo unit cell were not easily replaceable by lithium ions and 4 out of 12 not easily replaceable by ammonium ions.