Method of purifying coal tars for use in the production of carbon products

A method of preparing a starting material for use in the production of a carbon product, said method comprising the following steps:

• distilling or flash distilling coal tars, containing light component having an initial boiling point of not more than 280.degree. C. at atmospheric pressure with a fraction in an amount of at least 10% by weight which has a boiling point between the initial boiling point and 350.degree. C. at atmospheric pressure and xylene-insoluble components in an amount of 15% or less by weight, to remove said light component;
• said distilling or flash distilling being performed at a temperature of 250.degree. C. to 350.degree. C. to prevent substantially all thermally induced condensation, polymerization or decomposition reactions;
• obtaining a heavy component which remains in the bottom of the distillation or flash column;
• said heavy component having a greater xylene-insoluble content of at least 1% and not more than 10% by weight than that of said coal tar;
• and having a xylene-insoluble content of not more than 20% by weight of said heavy component;
• dissolving the obtained heavy component in 1-3 times its amount of a monocyclic aromatic hydrocarbon solvent to form a solution at a temperature ranging from ambient temperature to the boiling point of said solvent and which imparts flowability to said heavy component under atmospheric pressure or application of pressure;
• separating and eliminating the insoluble component from the resulting solution by filtration or centrifugation, which insoluble component comprises free carbon and components having very high molecular weights;
• and
• subsequently eliminating the solvent by distillation so as to obtain a purified heavy component substantially being free of the above insoluble component, as said starting material.