Effect of chlorine-containing compounds on evaporation of heavy metals in secondary gasification of fly ash from municipal solid waste incinerator

The experiment aims to investigate the influence of chlorination agents (NaCl, CaCl 2, and FeCl 3) on volatilization of heavy metals in fly ash from a Shenzhen municipal solid waste incinerator (MSWI) during thermal treatment by using a tube furnace. The results indicate that these three chlorination agents could promote the evaporation of heavy metal in fly ash with different performance. However, these chlorination agents had different effects on the volatilization of heavy metals. All of Pb and Cr could be almost volatilized without addition of chlorination agents, while chlorination agents addition produced significant effect on the volatilization of Zn and Cu: FeCl 3 ≈ CaCl 2 > NaCl. The optimal parameters for vaporization were obtained as follows: fly ash with addition of 15% CaCl 2 was treated at 1000°C for 2 hours under the condition of N 2 as carrier gas (0.6 L/min). © 2012 Peking University.