Identification and quantitative analysis of polarized light microstructure of coal-derived needle coke

Coal-derived needle coke was prepared using refined coal tar pitch as feedstock. Its polarized light microstructure was quantitatively analyzed by bricc-m coal macerals automatic testing system with RICC-Imager analysis software and the dot counting method. Microstructure of needle coke was characterized using scanning electron microscope. The results indicate that the large domain streamline structure content of the prepared green coke is 87.8% under carbonization conditions of 490 ℃, 0.2 MPa and 6 h, which shows good optical microstructure. Compared with the traditional quantitative analysis method, the quantitative analysis using dot counting method is more accurate and efficient. It can be used as an effective means for quantitative analysis of needle coke microstructure.