The Formation Of Coal Tar Pitch Based MCMBs And Isotropic Spherical Carbon

Utilization of coal tar pitch in two fields was studied, including synthesis of MesoCarbonMicroBeads (MCMBs) and preparation of isotropic spherical carbon (SC).To investigate the mechanism of mesophase formation，as well as development and the impactfactors in MCMBs configuration transformation, researches in primary quinoline insolubls (PQI)and experiments on MCMBs secondary thermal condensation were carred out. The comprehensivecomposition and structure analysis of PQI revealed that PQI were mainly builded up of polycyclicaromatic hydrocarbon. The proportion of PQI was the dominant factor that the nucleation ofMCMBs would take a homogeneous way or the heterogeneous one during thermal condensationprocess. PQI might lead basic structural units (BSU) locally oversaturated, where the nucleation ofMCMBs took place prior, and thus in kinetics the nucleation process behaved in a self-catalyticway. The polycyclic aromatic hydrocarbon structure of PQI might be the key factor to thedisclination of MCMBs. In the research of MCMBs development, by the method introducingMCMBs as co-carbonization addition in thermal condensation process, it was found thatcontinuative growth on added MCMBs took place. The secondary thermal condensation processincluded self-original nucleation of raw pitch and secondary growth of introduced MCMBs. Thesetwo parallel developing channels accompanied and competed with each other at the same time.The self-original nucleation of raw pitch was affected by the small particles of introducedMCMBs as well. It could be concluded that during the growth process of MCMBs, BSU ofMCMBs moved from parent pitch into MCMBs across the interface and continuously builded upMCMBs.For further utilization of thermal-modified hard pitch, a kind of thermal-modified coal tar pitchwhich was unable to be prepared into pitch spheres by normal suspending method was blendedwith some quantity of mid temperature pitch as well as naphthalene. The received pitches weresuccessfully made to spheres in suspending way.