Behavior of metals in ash melting and gasiWcation-melting of municipal solid waste (MSW)

In this study, metal behavior in ash-melting and municipal solid waste (MSW) gasiWcation-melting facilities were investigated. Eight ash-melting and three MSW gasiWcation-melting facilities with a variety of melting processes and feedstocks were selected. From each facility, melting furnace Xy ash (MFA) and molten slag were sampled, and feedstock of the ash-melting processes was also taken. For the ash melting process, the generation rate of MFA was well correlated with the ratio of incineration Xy ash (IFA) in feedstock, and this was because MFA was formed mostly by mass transfer from IFA and a limited amount from bottom ash (BA). Distribution ratios of metal elements to MFA were generally determined by volatility of the metal element, but chlorine content in feedstock had a signiWcant eVect on Cu and a marginal eVect on Pb. Distribution ratio of Zn to MFA was inXuenced by the oxidizing atmosphere in the furnace. High MFA generation and distribution ratio of non-volatile metals to MFA in gasiWcation-melting facilities was probably caused by carry-over of Wne particles to the air pollution control system due to large gas volume. Finally, dilution eVect was shown to have a signiWcant eVect on metal concentration in MFA.  2005 Elsevier Ltd. All rights reserved.