The study of the structural, sorption, and electrochemical properties of a natural composite shungite

An integrated study of the structural, sorption, and electrochemical properties of a natural mineral shungite has been carried out. The composite nature of the mineral has been shown to predetermine its basic physicochemical characteristics. The isosteric heat of water adsorption = 70 kJ/mol, as estimated by calorimetry and gas chromatography, reflects the interaction of its molecules with vicinal hydroxyl groups of the silica component of shungite. Adsorption heats, = 40–45 kJ/mol, is governed by the carbon moiety of the sorbent. Higher adsorption heats of benzene on shungite, as compared with those of hexane, are indicative of the interaction of its molecules with active sites of the carbon and silica moieties of the mineral. The type and number of these sites have been determined by potentiometry and conductometry. The obtained adsorption parameters of shungite with respect to anionic organic compounds enable us to recommend its application as a sorbing material for filtration.