Research on preparation of sintered foamed ceramics from fly ash

Abstract This study used fly ash as the main raw material to prepare porous ceramics via the foaming method, systematically investigating the effects of fly ash content, foaming agent dosage, sintering temperature, and holding time on the material's structure and properties. The results showed that the introduction of the foaming agent SiC significantly reduced material density and regulated the pore structure, but excessive addition led to a decrease in mechanical properties. The optimal process parameters determined through response surface methodology optimization were: fly ash addition of 40%, SiC dosage of 0.5%, sintering temperature of 1100°C, and holding time of 30 min. Under these conditions, the prepared porous ceramic achieved a porosity of 82.11%, a bulk density of 1.08 g/cm 3 , and a compressive strength of 5.63 MPa. Phase and microstructure characterization indicated that the main crystalline phases of the material were quartz and mullite, exhibiting a hierarchical pore structure. The porous ceramic prepared in this study holds potential application value in fields such as thermal insulation, adsorption, and carrier materials, providing a feasible pathway for the high‐value utilization of fly ash.