LAUSR

Abstract Graphitic carbon spheres (GCS) with diameters of 0.37–0.39 µm were prepared via hydrothermal carbonization combined with catalytic graphitization using glucose and Ni nanoparticles (NPs) as respectively a carbon source and a catalyst. They were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Raman spectroscopy. The optimal conditions for graphitization of amorphous carbon spheres produced from hydrothermal carbonization of glucose were 3 h firing at 1200 °C with 1.0 wt% of Ni catalyst. Three model types of Al2O3-SiC-C castables using ball pitch, GCS and graphite flake were prepared and tested. Compared with that in the case of using ball pitch or flake graphite, the water demand in the case of using GCS was lower, the bulk density, modulus of rupture and crushing strength were higher, and the thermal shock resistance was better (owing to the high graphitization degree and high thermal conductivity of GCS).