Low temperature upcycling of vitreous byproduct of the MSW plasma processing into multifunctional porous glass-ceramics

Mixtures of glass residues, deriving from the plasma processing of municipal solid waste ('Plasmastone'), and recycled glasses have been already converted into highly porous glass-ceramics by application of an inorganic gel casting technique (foaming, by intensive mechanical stirring, of alkali activated slurries) followed by sintering at 1000 degrees C. The full potential of recycled glass, however, has not been disclosed yet. The present investigation, in fact, demonstrates that boro-alumino-silicate glass, from discarded pharmaceutical vials, may allow for sintering of cellular glass-ceramics at particularly low temperature, i.e. at 800 degrees C. The full stabilisation of heavy metals from Plasmastone (already assessed for treatments at 1000 degrees C) is not compromised, whereas the low processing temperatures favour the separation of magnetite, in turn imparting new functionalities (e.g. electromagnetic shielding) to waste-derived glass-ceramic foams.