Recyclable Porous Glass-Ceramics from the Smelting of MSWI Bottom Ash

Ceramics, vol. 4, pp. 1–11

Abstract

Material from the electric arc furnace smelting of municipal solid waste incineration (MSWI) bottom ash was easily converted into highly porous glass-ceramics by a combination of inorganic gel casting and sinter-crystallization at 1000 °C. In particular, the gelation of aqueous suspensions of fine glass powders, transformed into “green” foams by intensive mechanical stirring, occurred with a limited addition of alkali activator (1 M NaOH). The products coupled the stabilization of pollutants with good mechanical properties (e.g., compressive strength approaching 4 MPa). Interestingly, they could be used also as raw material for new glass-ceramic foams, obtained by the same gel casting and sintering method, with no degradation of chemical stability. Limitations in the crushing strength, derived from the limited viscous flow densification of semi-crystalline powders, were overcome by mixing powders from recycled foams with 30 wt% soda-lime glass. The new products finally featured an even higher strength-to-density ratio than the foams from the first cycle.

Authors 4

1. Patrícia Rabelo Monich

   University of Padua

   Affiliation as printed

   Dipartimento di Ingegneria Industriale, Università degli Studi di Padova, Via Marzolo 9, 35131 Padova, Italy

2. Hugo Lucas Aachen IME Process Metallurgy and Metal Recycling

   RWTH Aachen University

   Affiliation as printed

   IME Process Metallurgy and Metal Recycling, RWTH Aachen University, 52056 Aachen, Germany

3. Bernd G. Friedrich Aachen IME Process Metallurgy and Metal Recycling

   RWTH Aachen University

   Affiliation as printed

   IME Process Metallurgy and Metal Recycling, RWTH Aachen University, 52056 Aachen, Germany

4. Enrico Bernardo corresponding

   University of Padua

   Affiliation as printed

   Dipartimento di Ingegneria Industriale, Università degli Studi di Padova, Via Marzolo 9, 35131 Padova, Italy