Study on synthesis of environmentally conscious Sialon multiphase ceramics from coal gangue

Environmentally conscious Sialon multiphase ceramics have been synthesized from coal gangue by carbothermal reduction nitridation (CRN), and their properties and structure were investigated with aid of SEM, XRD etc. In laboratory, elongated beta-Sialon ceramic matrix composites can be fabricated using colloidal process and CRN process, and the relevant density of sintered body, of 2.38 g (.) cm(-3) can be obtained. The industrial test indicated that the mechanical properties (e.g. 2.82 g (.) cm-3 of density) of Sialon composite derived from coal gangue is superior to that from clay. Their Vicker hardness and fracture toughness were 10.44 GPa and 5.17 MPa (.) m(1/2) respectively, which is 1.05 and 1.56 times bigger than those derived from clay (no doping gangue). This study will supply a novel process to develop large-scaled ecological gangue into high-value ceramics.