Acid Resistance and Ion-Exchange Capacity of Natural Mixtures of Heulandite and Chabazite

The recovery and immobilization of metals from wastewater often occurs in an acidic environment that destroys the structure adsorbents such as zeolites, which are porous crystalline aluminosilicates. influence hydrochloric acid solutions on properties two natural mixtures heulandite (HEU) chabazite (CHA)—tuff Georgian Dzegvi-Tedzami deposit (HEU/CHA ≈ 8) rock Kazakhstani Chankanay (HEU/CHA≈1)—was studied by X-ray energy dispersion spectra diffraction patterns, well adsorption water, benzene, nitrogen methods. It was found acid-mediated dealumination, decationization, dissolution, changes systems micro- mesopores depend nature chemical composition initial zeolites. is concluded that, under acid, (i) zeolite micropores become accessible to relatively large molecules ions, surface area adsorbent increases; (ii) volume decreases, pores with a diameter less than 4 nm predominant; (iii) terms degree dealumination dissolution rate, more acid-resistant heulandite; (iv) retains high ion-exchange capacity environment, while heulandite, treated dilute solutions, uptakes amounts valuable silver, copper, zinc.