Modification of a shungite material for the application in sorption and membrane technologies

Abstract

Shungites are perspective materials for the application in manufacturing industries. They evoke interest as adsorbents and catalysts for water purification devices, as well as the materials with unique properties for various branches of chemical industry, pharmacology, medicine, ecology. Shungites are characterized by a variety of elementary composition and mineral bases – aluminosilicates, siliceous, carbonates, and the number of carbon materials. This paper describes the effect of physical and chemical modification procedures of crude mineral shungite-III (Karelya, Russia) on its elementary composition and different properties. Shungite is a solid dispersion system where micro regions observed with different elementary composition up to almost individual micro phases of Si, C, Fe, S. The mechanochemical modification procedure of shungite was proposed that permits to obtain nanodispersed powder with carbon content up to 75%, which was confirmed by scanning electron microscopy and EDAX. The properties of natural sorbents depend on their porosity and specific surface. The heating of shungite-III well over 500oС results in the loss of 10% of carbon content, but the powder dispersivity is twice as much. The thermoactivation of ultradispersed shungite powder with water vapor results in the increase of powder dispersivity and porosity, as well as the carbon content decreases up to zero.