Thermal/mechanical properties of cordierite synthesized using coal gangue as a refractory material

Abstract

Coal gangues i a solid waste during the coal mining process and the accumulation of coal gangue will harm the environment. Therefore, solid waste utilization of coal gangue is required to reduce the environmental damage. In this paper, cordierite ceramics are successfully prepared via a solid-phase sintering using coal gangue, Al₂O₃, and MgO as raw materials. The effects of sintering temperatures on the microstructures, phase stability, and thermal properties of ceramics are investigated. The results show that the properties of cordierites prepared at 1200°C are close to those of prepared by the traditional method, and the synthesized ceramics have thermal expansion coefficients (TECs) and conductivity of 4.1–10⁻⁶ K⁻¹ and 1.72 W·m⁻¹ K⁻¹ at 900°C, respectively. The sample prepared at 1200°C has good wear resistance (η) with a wear resistance coefficient of 0.507, and an excellent thermal shock resistance, which can withstand 15 times of cold and hot shocks at 1100°C without any cracks on the surface. This study systematically elucidates the thermal/mechanical properties of the synthesized cordierite, and the feasibility of using coal gangue as raw materials prepared cordierite ceramics as refractory materials. This work presents an effective solution to mitigate the challenge of coal gangue disposal.