Current time in Korea 14:27 May 23 (Thu) Year 2019 KCS KCS Publications
KCS Publications
My Journal Log In Register
HOME > Search > Browsing(JKCS) > Archives

Journal of the Korean Chemical Society (JKCS)

ISSN 1017-2548(Print)
ISSN 2234-8530(Online)
Volume 46, Number 6
JKCSEZ 46(6)
December 20, 2002 

 
Title
Characterization of Cation Exchange and Cesium Selectivity of Synthetic Beta-Dicalcium Silicate Hydrate

Characterization of Cation Exchange and Cesium Selectivity of Synthetic Beta-Dicalcium Silicate Hydrate
Author
S. A. El-Korashy

S. A. El-Korashy
Keywords
Abstract
240℃와 Ca/Si=2 몰 비율의 열수상태에서 합성된 고체 베타-디칼슘 실리케이트 하이드레이트(β-C2SH)는 Fe, Cu, Zn, Cd, 및 Pb와 같은 2가 금속 양이온에 대한 양이온 교환 성질을 보여준다. 그 고체에 희한 금속 양이온 흡인력은 Fe2+〉Cu2+〉Zn2+〉Cd=Pb2+의 순서로 됨이 밝혀졌다. 고체에 세슘 선택성은 Li+, Na+ 및 K+와 같은 1가 양이온이나 Ca++, Mg++ 및 Ba++와 같은 2가 양이온이 Cs+보다 백배이상 진한 상태에서 나타내었다. Cs+의 흡인력은 Mg++의 존재하에서 최대치를 보여주었고, 반면에 K+의 존재하에서 최소치를 보여주었다. 2가 금속이온에 대한 β-C2SH의 다른 친화도는 이들 이온을 분리하는데 사용 할수 있다. 또한 β-C2SH에 희한 금속 양이온 교환에 대한 반응경로 및 세슘 선택성이 연구되었다.

Solid beta-dicalcium silicate hydrate (β-C2SH) synthesized under hydrothermal conditions at 240℃ and Ca/Si=2 molar ratio shows cation exchange properties towards divalent metal cations such as Fe, Cu, Zn, Cd, or Pb. The ability of metal cation uptake by the solid was found to be in the order: Fe2+>Cu2+>Zn2+>Cd2+≫Pb2+. Cesium selectivity of the solid was demonstrated in the presence of univalent cation such as Li+, Na+ and K+ and divalent cations such as Ca2+, Mg2+ and Ba2+, which are one hundred times more concentrated than the Cs+. The uptake of Cs+ is maximum in the presence of Mg2+ whereas it is minimum in the presence of K+. The different affinities of β-C2SH towards divalent metal cations can be used for the separation of those ions. Due to its selectivity for cesium it can be used in partitioning of radioactive Cs+ from nuclear wastes containing numerous cations. The mechanism of the metal cation exchange and cesium selectivity reactions by the solid is studied.

Page
515 - 522
Full Text
PDF