Production of a self-adhering mesophase powder from anthracene oil for low pressure forming of graphite artefacts

Abstract

The objective of the investigation was to produce a high mesophase content pitch from low cost anthracene oil without the use of catalysts. The pitch product was then used to produce graphitic artefacts using only a low pressure (5 MPa) forming step followed by carbonization and graphitization at a comparatively high heating rate. The heat treatment times and temperatures were varied across a wide range but only material treated at 475 ºC produced a significant amount of mesophase. Furthermore only one pitch material resulted in a successful moulding which could be carbonized and graphitized. This pitch contained a significant portion (~ 8 wt%) of light material, which results in melting and flow behaviour during pressing, rather than sintering, if it is removed the material can no longer be successfully pressed. Due to the high mesophase content of the pitch a high density (1720 kg.m-3), highly graphitic artefact with minimal deformation during heat treatment is produced. The graphite product demonstrates grain separation but still results in a reasonable flexural strength of 4.5 MPa which may be improved further by re-impregnation depending on the requirement. This combined with its excellent purity and high yield make it a good candidate for nuclear applications.