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.