The NaA was ion-exchanged with Li⁺ and Ca²⁺ cations in water solution, then the adsorption isotherms and breakthrough curves of these zeolites were measured at 25℃.The data demonstrate that, for the NaA exchanged with Li⁺ or Ca²⁺, the higher the content of Li⁺ or Ca²⁺ in the A zeolite, the better the N₂ adsorption capacity and the adsorption selectivity of N₂ over Ar.The NaA zeolites exchanged with Li⁺ or Ca²⁺ have better adsorptive separation properties than NaA itself while the ion exchange level is high.From breakthrough curves it is known that the zeolites we studied have a suitable pressure for adsorption separation of N₂ and Ar.In the pressure range we studied, the best pressure is about 0.6 MPa.At this pressure, the A zeolite which is nearly completely exchanged by Ca²⁺ has better adsorptive separation property for N₂ and Ar than that exchanged by Li⁺ at the same exchange level.

Key words: zeolite NaA, separation of N₂ and Ar, adsorption isotherm, breakthrough curve