Volatilization and leaching behavior of heavy metals in MSW incineration fly ash in a DC arc plasma furnace

Three fly ash samples collected from different waste incinerators were vitrified using a direct current arc plasma furnace at 1250–1400 °C. The influence of water-wash extraction and wrapping pretreatment on the volatilization and leaching behavior of heavy metals was investigated. Results showed: After thermal arc plasma treatment, the volume reduction and weight loss of fly ash were in the range of 68.7–82.2% and 23.8–56.7%, respectively. The residual fractions (wt.%) of heavy metals in slag are in the following sequence: Cr 2 O 3 – SiO 2 (CAS) ratio for successful melting of fly ash is suggested to be CaO in range of 20–48%, Al 2 O 3 in range of 10–15%, and SiO 2 in range of 40–65%. Moreover, toxicity characteristic leaching procedure results showed that the leaching of heavy metals in slags was much lower than the standard limit of toxicity characteristic leaching procedure (TCLP).