The zeolites 13X and 4A were ion exchanged with different ions in water solution, then the adsorption isotherms and breakthrough curves of these zeolites were measured at 25 ℃. The data demonstrate that the zeolites 13X and 4A ion-exchanged with Ca~(2+) and Li~+ have higher adsorption capacity of N_2 than the original ones, but the Ar adsorption capacity of these ion exchanged zeolites is almost the same as that of the original ones. It is clear that these ion-exchanged zeolites have better adsorption selectivity for N_2 than for Ar. From breakthrough curves it is known that the zeolites have a suitable pressure for adsorption separation of N_2 and Ar. In the pressure range we studied, the best pressure is about 0.6 MPa. The adsorption capacities for N_2 and Ar in the gas mixture can be obtained from the breakthrough curves. Compared with the adsorption capacity for pure N_2 and Ar, It can be found that N_2 in the mixture has a large effect on the Ar adsorption capacity of the zeolites which have higher adsorption separation selectivity for N_2 and Ar.

Key words: MOLECULAR SIEVE, ADSORPTION, NITROGEN, ARGON, ISOLATION