RF thermal plasma vitrification of incinerator bottom and fly ashes with waste glasses from fluorescent lamps

Thermal plasma vitrification is a successfully used technology to treat and recycle hazardous wastes. High plasma temperatures enable to destroy complex molecules and to encapsulate the toxic elements in a non-leaching glass or ceramic matrix, obtaining non-hazardous wastes with large volume reductions. In this work, hazardous incinerator residues (bottom and fly ashes) have been treated by means of a laboratory scale radiofrequency (RF) thermal plasma source with the addition of coarse scraps of glass from dismantled fluorescent lamps. The obtained samples were characterized by scanning electron microscopy analysis (SEM), energy dispersion spectroscopy (EDS), X-ray diffraction (XRD) and leaching tests. The latter showed that toxic elements were completely encapsulated in the glass matrix, with release values below the law limits. Results of this work demonstrate the feasibility of bottom and fly ash vitrification in a batch of glass scraps from dismantled fluorescent lamps and can also provide useful insights for the optimization of vitrification processes carried out by the more widespread arc plasma furnaces.