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

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: Fe^{2+>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.}