Influence of the quinoline-insoluble matter in pitch on carbonization behaviour and structure of pitch coke

Abstract

The influence of the quinoline-insoluble matter in pitch on the carbonization behaviour and especially on the pitch-coke properties is of basic interest both for the production of pitch coke and the manufacture of carbon electrodes. A more isotropic coke is produced by increasing the amount of quinoline-insolubles. The coefficient of thermal expansion (CTE) by volume measured directly at the coke particle is strongly influenced by the type of quinoline-insoluble. A larger amount of the primary type of quinoline-insolubles causes a large increase of the CTE (volume) from 3.2 to 17.4 × 10 −6 K −1, whereas the secondary type influences the CTE only slightly. This strong influence of quinoline-insolubles on the structure of pitch-binder coke results in a remarkable increase of mechanical strength of carbon artefacts.