Abstract: A modified natural clinoptilolite, produced by treating a natural clinoptilolite with a suitable mineral acid or with a suitable alkali and then with a suitable mineral acid, is used as a catalyst in a process for the conversion of methanol and ammonia to give a product containing at least 50% by weight of monomethylamine.

Abstract: An ion exchange material for the removal of radioisotope cations such as the cations of caesium and strontium from an aqueous environment containing the radioisotope cation comprises a modified clinoptilolite produced by treating a natural clinoptilolite with sodium hydroxide at a concentration of approximately 2M or with hydrochloric acid at a concentration of from 0.1 to 5M for a suitable treatment time and at a suitable treatment temperature. The modified clinoptilolite is especially effective in the removal of radioisotope cations from an aqueous environment.

Abstract: A modified natural clinoptilolite, produced by treating a natural clinoptilolite with a suitable mineral acid or with a suitable alkali and then with a suitable mineral acid, is used as a catalyst in a process for the conversion of propane or butane to give a product containing at least 40% of ethene, propene or C.sub.4 hydrocarbons or a mixture thereof.