In situ wide-angle X-ray scattering study on the change of microcrystalline structure in Jincheng anthracite during high-temperature carbonization

Carbonization is an effective way to achieve the comprehensive utilization of coal. However, the in situ variation of graphite-like microcrystals, the basic structure of coal macromolecules, with heating and cooling during carbonization has not been fully characterized so far. Anthracite is a type of humic coal with the highest degree of coalification, and its structure change can be monitored well by X-ray scattering or diffraction techniques. In this contribution, an in situ synchrotron radiation wide-angle X-ray scattering (WAXS) study on high-temperature (1200°C) carbonization of a high-quality anthracite mined in Jincheng, China, is presented. The results show that, during the continuous process of heating and cooling, the size and height of the aromatic lamellae first decrease and then increase with minima at 900 and 1000°C, respectively, while the interlayer spacing first increases and then decreases with a maximum at 1000°C. The roadmap of graphite-like microcrystalline structure change during the whole continuous process of heating and cooling is revealed and described.