This report has reviewed the general properties, composition, pyrolysis, and effect on molded graphite bodies of coal-tar pitch.nAlthough no complete quantitative analysis of pitch has been reported, enough work has been done to give a fairly good picture of the composition. It is estimated that as many as 5000 different individual compounds are present in pitch in varying amounts. Practically all of them are in the same class, that of multiringed aromatic hydrocarbons. The majority of these are compounds of 3 to 7 rings with molecular weights ranging from 170 to 380 and are present as "associated colloids" or loosely bonded aromatic clusters. An insoluble phase similar to carbon black is also present which, although it makes no direct contribution to the binding action, nevertheless influences the properties of both the pitch itself and the molded graphite products made with pitch.
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