PROCESS FOR PRODUCING CRUDE COAL-TAR PITCHES HAVING IMPROVED PROPERTIES AND USE OF SAME

摘要

Depending on requirements and intended use crude pitches are mixed from coal-tar-pitch fractions obtained by extraction with an above-critical gas and an entraining agent from the above-critical solution by gradually changing the pressure and the temperature. Ash-free as well as QI-free and TI-free fractions are obtained. Primarily low-boiling aliphatic and olefinic hydrocarbons are used as extracting agents and aromatic hydrocarbons as entraining agents. The crude pitches are used, for example, for producing carbon black and for producing carbon mouldings.