Porous glass-ceramics made from microwave vitrified municipal solid waste incinerator bottom ash

• Published in: Construction & building materials 2021-02, Vol.270, p.121452, Article 121452
• Main Authors: Flesoura, Georgia, Monich, Patricia R., Murillo Alarcón, Roberto, Desideri, Daniele, Bernardo, Enrico, Vleugels, Jef, Pontikes, Yiannis
• Format: Article
• Language: English
• Subjects: Alkali activation; Microwave heating; MSWI bottom ash; Porous glass-ceramics; Vitrification
• ISSN: 0950-0618; 1879-0526
• DOI: 10.1016/j.conbuildmat.2020.121452

•Microwave vitrified bottom ash transformed into materials comparable to aerated concrete.•Vitrified bottom ash porous glass-ceramics produced with 70 vol% porosity and 3 MPa strength.•Weak alkali activation and sinter-crystallization provided hardened porous materials.•Vitrified bottom ash porous glass-ceramics may be used in electro-catalytic applications. Global warming and depletion of resources have fueled research towards innovative building materials of low environmental impact and high performance engineering properties. Porous glass-ceramics were synthesized using municipal solid waste incinerator (MSWI) bottom ash (BA) as a starting material. BA was initially milled and then vitrified, as a purification step, by direct microwave heating, characterized by a high glass yield. Highly porous glass-ceramics were produced by intensive mechanical stirring of vitrified bottom ash (VBA) aqueous suspensions under weak alkali activation (1 M NaOH and 2.5 M NaOH) and sinter-crystallization at 800 °C or 900 °C. The obtained glass ceramics, with up to 70 vol% porosity, exhibited compressive strength well above 1 MPa, being comparable to lightweight construction materials, such as aerated concrete. High relative permittivity was measured for the 10 wt% soda-lime glass doped porous VBA material sintered at 800 °C, paving the way for its use as a potential semiconductor catalyst.