The different properties of lightweight aggregates with the fly ashes of fluidized-bed and mechanical incinerators

• Reuse of MSW fly ash from fluidized-bed and mechanical-bed for lightweight aggregates were compared.
• The properties of lightweight aggregates with different fly ash ratios and sintered at different temperatures were evaluated.
• Fly ash of fluidized-bed MSW incinerator has better recycling and reusing potentials due to its composition and properties.

The properties of lightweight aggregates (LWAs) manufactured from the fly ashes of municipal solid waste (MSW) fluidized-bed (FB) incinerators and mechanical-bed (MB) incinerators were compared and investigated. The fly ashes from FB and MB incinerators were mixed with the reservoir sediment and sintered at 1000–1200 °C to produce LWAs. Experimental results show that each LWA product complied with the TCLP standards. Adding MB fly ash to LWA obtained relatively higher crushing strength than adding FB fly ash. However, the LWAs with FB fly ash were less hazardous, lighter in weight, lower in water absorption, and higher in stability than those with MB fly ash. The reuse of FB fly ash in LWA has great recycling potential from the perspective of environmental sustainability.