Integrated utilization of municipal solid waste incineration fly ash and bottom ash for preparation of foam glass–ceramics

Abstract

For the purpose of solid waste co-disposal and heavy metal stabilization, foam glass–ceramics were produced by using municipal solid waste incineration (MWSI) bottom ash and fly ash as main raw materials, calcium carbonate (CaCO3) as foamer and sodium phosphate (Na3PO4) as foam stabilizer. The influences of the raw material composition, foaming temperature and foaming time on the properties were investigated. Porosity, bulk density, mechanical property and leaching of heavy metals were analyzed accordingly. The product, foamed at 1150 °C for 30 min with 14% fly ash and 74% bottom ash, exhibits excellent comprehensive properties, such as high porosity (76.03%), low bulk density (0.67 g·cm−3) and high compressive strength (10.56 MPa). Moreover, the amount of leaching heavy metals, including Cr, Pb, Cu, Cd and Ni, in foam glass–ceramics is significantly lower than that of the US EPA hazardous waste thresholds. This study not only realizes the integrated utilization of bottom ash and fly ash, but also addresses a new strategy for obtaining foam glass–ceramics.