R. Levanmao et al., MODIFIED ZEOLITES FOR THE REMOVAL OF CALCIUM AND MAGNESIUM FROM HARD WATER, Journal of materials chemistry, 4(7), 1994, pp. 1143-1147
The cation-exchange capacity (cec) and the pore size of zeolite materi
als are the two key factors which influence the removal of calcium and
magnesium in aqueous solution. Na-X and Na-Y zeolites have been modif
ied by selective extraction of Si from the zeolite framework using sod
ium carbonate. At ambient temperature, the modified Na-X zeolite was m
ore efficient than the Na-A commercially used in detergency, for both
Ca and Mg ions.