Low-Cost Foamed Ceramics with Enhanced Mechanical Performance and Uniform Pore Size Structure

Due to the lack of effective utilization, fly ash and red mud accumulate in large quantities and cause serious harm to the environment. In this experiment, a low-cost preparation of foamed ceramics was realized by applying the foaming agent addition method using fly ash and red mud. The results indicated that temperature and foaming agent content significantly affected the macrostructure, microstructure, crystalline phases, and properties of the foamed ceramics. Specifically, a formulation comprising 45 wt.% fly ash, 45 wt.% red mud, 10 wt.% clay, and 1 wt.% SiC (addition), sintered at 1210 °C, yielded a compressive strength of 8.2 MPa, a bulk density of 1.17 g/cm3, a water absorption rate of 32.05%, and an apparent porosity of 37.59%. The as-prepared materials demonstrate potential as cost-effective building materials, putting forward an effective approach for the high-value utilization of fly ash and red mud.