Relationships between quality of coals, resulting cokes, and micro-Raman spectral characteristics of these cokes

• Coke microstructure analyzed by micro-Raman spectroscopy streamline mode
• Correlations found between micro-Raman parameters of coke and its quality and properties of the parent coals
• Micro-Raman analysis of coke can be used for prediction of CRI and CSR values.

The research was carried out on 18 single-coal cokes obtained in semi-industrial conditions from different parent coals (Rr = 0.84–1.43%). Coke microstructure was investigated by micro-Raman spectroscopy with application of the streamline mode. The obtained Raman spectra are typical for poorly organized carbonaceous material. Correlations were found between the volatile matter content, all maceral reflectance scan, mean random vitrinite reflectance and carbon content of the parent coals, and the full width in half maximum (FWHM) of the D2 and G bands in the Raman spectra of the resulting cokes. There is a non-linear relationship between dilatation and the G band FWHM. Coke reactivity index (CRI) and coke strength after reaction (CSR) are correlated with the D2, G and D4 band FWHMs. Based on the G and D2 band widths, it is possible to predict roughly the CSR and CRI values of cokes.