SORPTION AND DIFFUSION OF RARE GASES IN HEULANDITE AND STILBITE

With a view to establishing the potentiality of heulandite and stilbite as sorbents and encapsulating media for gases, the uptake of Ne, Ar and Kr in these zeolites has been studied at pressures up to 10000 p.s.i. and at relatively elevated temperatures. Stilbite and heulandite were not stable to outgassing at high temperatures but with appropriate activation, they sorbed rare gases copiously. For Ar and Kr as sorbates trapping was improved by allowing the crystals to be partially rehydrated when still charged with the rare gas. Diffusion coefficients, D, of the rare gases were determined in the crystals before and after partial rehydration. It was found that D was decreased and the energy of activation for diffusion of the larger rare gases was increased by rehydration. © 1969.