4. Conclusions
In this paper, a new kind of shaped silicalite-1 all-silica zeolite with a binder which was for directly industrial application other than power was synthesized and tested for iodine adsorption performance. Although the existence of binder in shaped silicalite-1 all-silica zeolite, it still exhibited high iodine adsorption capacities up to 507 mg g-1, attributed to the appropriate micropore which had stronger adsorption potential and hydrophobic surface. This iodine adsorption capacity was superior to inorganic adsorbents such as silver-containing zeolite mainly used currently, and was also comparable with that of power silicalite-1 reported previously, demonstrating the molding process of shaped silicalite-1 with binder was successful. The adsorption results indicated that the mechanisms of adsorption followed physical combination. Moreover, the shaped silicalite-1 all-silica zeolite could be cyclic utilization due to its reversible adsorption, and the structure of shaped silicalite-1 was still stable after iodine desorption. The static iodine adsorption capacity obtained on all-silica zeolites at the certain temperature of off-gas during spent fuel reprocessing is filling the gap which has not been reported yet at 348 K. Instead of high price of silver-containing adsorbents, this lower cost of shaped silicalite-1 all-silica zeolite which can be directly applied in industry provides the feasible path in iodine removal aspects.