Properties of graphitized pitch cokes: Influence of the precarbonization treatment of pitch on the formation of graphitic structure

Abstract

X-ray analysis, an abradability test, and porosimetric measurements were used to study the effect of the original texture of pitch cokes on properties of graphitization products obtained by their thermal processing at 2100 °C. It has been established, from the interlayer spacing d 002, crystallite dimension L c , relative peak intensity I rel , and parameters of abradability, that the product F 2100 prepared from pitch coke with highly directional structure, obtained by two stage filtration of molten pitch during the pre-carbonizing treatment, was characterized by the properties most suitable for its intended purpose. Comparing them with the graphitization products of quinoline extract (QS), pitch coke from unprocessed pitch containing quinoline - insoluble (QI) substances, and of the petroleum coke, the evidence could be brought that the transition into the graphitic structure could be ‘thermally accelerated’, for the sample F 2100, by 200 to 250 K. There could be found, in all graphitized samples, a new conspicuous region of mesopores with maxima of radii of 7.5 or 22.5 nm, respectively, corresponding to slots formed during the destruction of the lamellar structure.