In-situ SAXS study on fractal of Jincheng anthracite during high-temperature carbonisation

Abstract

ABSTRACT The change in the fractal structure of anthracite mined in Jincheng, China, during high-temperature (1200°C) carbonisation was studied in situ by small-angle X-ray scattering (SAXS) at Beijing Synchrotron Radiation Facility (BSRF). The results show that, during carbonisation, the anthracite structure changes from a pore fractal to a surface fractal and then back to a pore fractal. With increase of temperature, the fractal dimension of the sample presents a trend of rise, decline, rise and decline again, which probably corresponds to the four stages of physical desorption, thermal decomposition, thermal condensation, and residual carbon aging in the process of carbonisation. The pore fractal exists in the initial and final stages, and the surface fractal exists in the middle two stages.