Ion-exchange techniques were used to study the diffusion of 45Ca, 24Na and 42K in natural chabazites. The diffusivity at 20 to 60C could be described by:

Na:     D(m2/s) = 1.45 x 10-9exp[-33.8(kJ/mol)/RT]

K:     D(m2/s) = 1.5 x 10-10exp[-29.7(kJ/mol)/RT]

The diffusivity of Ca at 21C was 3 x 10-20m2/s, and the diffusivities of Na and K at 30C were 1.58 x 10-15 and 9.6 x 10-16cm2/s, respectively.

Kinetics of Ion Exchange. N.M.Brooke, L.V.C.Rees: Transactions of the Faraday Society, 1969, 65[562], 2728-39