Preparation of mesocarbon microbeads from coal tar

Mesocarbon microbeads (MCMB) was prepared from coal tars with various prima ry pyridine insoluble fraction (PI) contents from 0 to 3.7 wt %, through he at treatment at 430-480 degrees C for different time under autoginious pres sure. The heat treated coal tars were filtered under 150 degrees C and the residue was rinsed with pyridine. MCMB was obtained as the pyridine insolub le fraction. Both yield and diameter of MCMB increased with the increasing of reaction temperature and holding time. It was found that primary PI also had strong influence on the formation of MCMB, which restricting coalescen ce between mesophase spheres by sticking on the surface of mesophase sphere s or dispersing in the matrix. Low temperature, short reaction time and hig h PI content resulted in the MCMB with small diameter and narrow size distr ibution. Carbon block with 1.75 g/cm(3) density could be easily obtained fr om the MCMB after molded under 100 MPa and carbonized at 1000 degrees C. (C ) 1999 Kluwer Academic Publishers.