METHOD OF PRODUCING THERMALLY EXPANDED GRAPHITE, THERMALLY EXPANDED GRAPHITE AND FOIL BASED THEREON Russian patent published in 2013 - IPC C01B31/04 C04B35/536 

FIELD: chemistry.

SUBSTANCE: invention can be used to produce flexible graphite foil which is used in production of sealing, heat-shielding and electroconductive articles. Graphite particles are treated with concentrated nitric acid to obtain a suspension containing intercalated graphite compounds and nitric acid. The obtained suspension is mixed with dry particles of carbon materials capable of intercalation, e.g., graphite, thermally expanded graphite, activated carbon, in an amount which enables subsequent intercalation thereof with nitric acid from the suspension. The mixture is held for intercalation of the added particles and the obtained intercalated graphite compounds are blown with air at temperature not higher than 40°C. The intercalated graphite compounds are then heated in thermal shock conditions, e.g., by gas heating, to obtain thermally expanded graphite. The thermally expanded graphite has high carbon output of not less than 102%, packed density of not more than 3.0 g/cm³, specific surface area of not less than 14 m²/g. The foil made from the thermally expanded graphite has strength of not less than 3.3 MPa.

EFFECT: invention provides efficient and wasteless technology.

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