Sumitomo Metal Industries, Inc.

Kureha Kagaku Kogyo Kabushiki Kaisha

Sumikin Chemical Co., Ltd.

Katsuyuki Ohshima

Katsumi Satoh

Yoshihiko Sunami

Tohru Iwahashi

Kenichi Iwaguro

A process for refining coal-derived heavy carbonaceous materials such as pitch to remove quinline insolubles therefrom is disclosed. The process comprises providing a coal-derived heavy carbonaceous material from which all the components having normal boiling points of 270.degree. C. or below and all or part of the components having normal boiling points ranging from 270.degree. C. to 360.degree. C. have been removed; heating the heavy carbonaceous material to make it fluid; mixing the heated carbonaceous material with a ketone solvent having a boiling point below 200.degree. C. for a period sufficient to precipitate coarse insoluble particles in the mixture; separating the precipitated particles from the mixture; and removing the ketone solvent from the mixture, leaving a refined, coal-derived heavy carbonaceous material which is suitable for use in the production of high-grade carbon stocks such as needle coke, carbon fibers, high-purity carbon, etc., and for use as an impregnant or binder pitch.

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Ibaraki, Japan

Katsuyuki Ohshima