Differences and correlations between microstructure and macroscopic properties of mesophase cokes derived from the components of high temperature coal tar pitch

It has been universally believed that the soluble and insoluble components of coal tar pitch obtained by solvent extraction were good precursors to prepare mesophase cokes. The microstructure and macro properties of mesophase cokes derived from the soluble and insoluble components are varied in general. In order to study the differences and correlations between the microstructure and macro properties of mesophase cokes, 16 kinds of component in two categories have been prepared mesophase cokes as the raw materials. Briefly, Scanning electron microscope (SEM), Polarizing Microscope (PM), Raman spectroscopy, X-Ray Diffraction (XRD), thermogravimetry (TG) and Micro-strength intensity (MSI) have been used to characterize microstructure and macro properties of cokes. In fact, the graphite structure in extract-based cokes is larger and more orderly than that in residue-based cokes. The MSI of residue-based cokes (66 - 81%) is higher than that of extract-based cokes (53 60%), while Tmax (615 - 645 degrees C and 680 - 715 degrees C) of the two are opposite. In a word, the results indicate that all data of the two categories of cokes go to bipolar distribution. And the results of this work were helpful for understanding and providing direction for the evaluation of cokes used to prepare isotropic and anisotropic graphite.

Automated summary

The study found that mesophase cokes derived from extract-based coal tar pitch have larger and more orderly graphite structure, while residue-based cokes have higher micro-strength intensity. The Tmax values of the two cokes are opposite, and all data of the two cokes exhibit bipolar distribution.