Effect of Fe2O3 additives on the sintering mechanism of a high strength ceramsite from a CFB fly ash

The sustainable reutilization of industrial solid waste offers a viable strategy to address environmental concerns associated with coalfired power generation This study investigates the role of FeO additives in enhancing the sintering behavior microstructural evolution and structural properties of highstrength ceramsite synthesized from circulating fluidized bed CFB fly ash A series of ceramsite samples with varying FeO contents 015 wt were sintered at temperatures ranging from 1150C to 1300C to evaluate the influence of FeO on material performance The results revealed that the addition of 5 10 wt FeO at 1300C produced optimal results Microstructural analyses using Xray diffraction XRD scanning electron microscopy SEM and thermogravimetricdifferential scanning calorimetry coupled with Fouriertransform infrared spectroscopy TGDSCFTIR demonstrated that FeO effectively promotes liquidphase sintering facilitates mullite crystallization and improves particle bonding and densification while simultaneously moderating gas evolution However excessive FeO content 10 wt led to reduced strength and densification due to increased porosity and decreased liquidphase viscosity This research not only highlights the dual function of FeO as both a fluxing and structural stabilizing agent but also provides a practical route for converting coalbased solid waste into highperformance construction materials The findings contribute to the advancement of sustainable building technologies and support circular economy goals through efficient resource recovery and waste minimization