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The article considers the processes leading to a change in the structure and properties as a result of calcination followed by acid treatment of heulandite-containing tuff from the Georgian Dzegvi-Tedzami deposit. The samples obtained by heat-acid treatment were studied by the X-ray energy dispersion spectra and diffraction patterns, as well as by adsorption of water and benzene methods. It was found that pre-heat treatment reduces weight loss and the degree of dealumination during subsequent acid treatment, and a...

Natural zeolites, a family of hydrated aluminosilicates, are important raw materials for micro and nano technologies due to their molecular-sieve, ion-exchange and catalytic properties. Their porous crystalline framework is built from alternating SiO4 and AlO4 - tetrahedra forming cages and channels, and improvement of zeolite performance is possible by thermal and chemical treatment. The influence of hydrochloric acid and calcination on heulandite-containing tuff from the Georgian Dzegvi-Tedzami deposit was studi...

Purified natural clinoptilolite as well as clinoptilolite converted into hydrogen and sodium form have been contacted with 0.1 mol/L silver nitrate solution at a ratio solid to liquid equal to 1 to 20, in order to load silver ions (Ag+) on the zeolite support. It has been found that sodium modified clinoptilolite exchanged in highest degree Ag+ ions, followed by natural zeolite. Preliminary transformation of natural clinoptilolite into hydrogen form leads to decreasing of zeolite ability to bind Ag+ ions. The kine...