Distribution of heavy metals in the flue gas from municipal solid waste incineration fly ash melt process

Abstract

Experiments on treatment of municipal solid waste incineration fly ash with and without contact with a molten iron phase were carried out to investigate the behaviour of heavy metals in fly ash. The focus was to determine whether the contaminant heavy metals would migrate to the iron phase, remain in fly ash slag or become volatile and found in the condensed secondary fly ash from the treatment. The effects of temperature, heating time and basicity of the fly ash on the distribution of heavy metals have been investigated. These results of analysis indicated that the main contaminants from the fly ash that were volatilized and collected via fabric filter bags were KCl, Pb2OCl2 and ZnCl2. The percentages of the volatilized Pb and Zn collected increased slightly as temperature, heating time and basicity increased. Melting the municipal solid waste incineration fly ash using molten iron versus simple melting at the same temperature promoted the volatilization of Zn, Pb and Hg.