title: Recycling of MSWI fly ash by means of cementitious double step cold bonding pelletization: Technological assessment for the production of lightweight artificial aggregates.
abstract: In this work, an extensive study on the recycling of municipal solid waste incinerator fly ash by means of cold bonding pelletization is presented. The ash comes from an incineration plant equipped with rotary and stoker furnaces, in which municipal, hospital and industrial wastes are treated. Fly ash from waste incineration is classified as hazardous and cannot be utilized or even landfilled without prior treatment. The pelletization process uses cement, lime and coal fly ash as components of the binding systems. This process has been applied to several mixes in which the ash content has been varied from 50% (wt.%) up to a maximum of 70%. An innovative additional pelletization step with only cementitious binder has been performed in order to achieve satisfactory immobilization levels. The obtained lightweight porous aggregates are mostly suitable for recovery in the field of building materials with enhanced sustainability properties. Density, water absorption and crushing strength ranged from 1000 to 1600 kg/m(3), 7 to 16% and 1.3 to 6.2 MPa, respectively, and the second pelletization step increased stabilization efficiency. The feasibility of the process has been analyzed by testing also concrete specimens containing the artificial aggregates, resulting in lightweight concrete of average performance.
authors.affiliation: Department of Engineering, University of Naples 'Parthenope' Centro Direzionale, Isola C4, 80143 Naples, Italy; INSTM, Consorzio Interuniversitario per la Scienza e Tecnologia dei Materiali, Via G. Giusti, 9. 50121 Firenze, Italy. Electronic address: colangelo@uniparthenope.it.
authors.forename: Francesco
authors.initials: F
authors.lastname: Colangelo
authors.affiliation: Department of Engineering, University of Naples 'Parthenope' Centro Direzionale, Isola C4, 80143 Naples, Italy; INSTM, Consorzio Interuniversitario per la Scienza e Tecnologia dei Materiali, Via G. Giusti, 9. 50121 Firenze, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Messina
authors.affiliation: Department of Engineering, University of Naples 'Parthenope' Centro Direzionale, Isola C4, 80143 Naples, Italy; INSTM, Consorzio Interuniversitario per la Scienza e Tecnologia dei Materiali, Via G. Giusti, 9. 50121 Firenze, Italy.
authors.forename: Raffaele
authors.initials: R
authors.lastname: Cioffi
keywords: Artificial aggregate concrete; Cold bonding pelletization; Double step granulation; Leaching; Municipal solid waste incinerator fly ash; Stabilization/solidification