[Influence of additives on decomposition of PCDD/Fs during MSWI fly ash melting process]

The melting process of municipal solid waste incinerator (MSWI) fly ash was investigated in order to study the influence of additives on decomposition characteristics of dioxins (polychlorinated dibenzo-p-dioxins and polychlorinated dibenzo-p-furans, PCDD/Fs). The melting treatment of MWSI fly ash was performed at a batch-melting furnace with two types of additives, CaO and liquid ceramic (LC), at different melting temperatures, melting atmospheres and treatment times. The results demonstrate that the effect of CaO on PCDD/Fs' decomposition changed with the type of atmosphere. The decomposition and removal efficiency (DRE) of dioxins increased slightly with 20% CaO in an oxidative atmosphere, while it decreased obviously in an inert atmosphere. There is an important influence by liquid ceramic on the decomposition of PCDD/Fs. The DRE of PCDD/Fs in MSWI fly ash increased from 99.997% to 100% with the addition of LC increasing from zero to 10% at 1400 degrees C. The temperature, in which the PCDD/Fs were completely decomposed, decreased from 1460 degrees C to 1100 degrees C when 10% LC was added into fly ash.