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

Abstract

In this study, metal behavior in ash-melting and MSW gasification-melting facilities were investigated. Eight ash-melting and three MSW gasification-melting facilities with a variety of melting processes and feedstocks were selected. From each facility, melting furnace fly 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 fly 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 significant effect on Cu and a marginal effect on Pb.Distribution ratio of Zn to MFA was influenced by the oxidizing atmosphere in the furnace.High MFA generation and distribution ratio of non-volatile metals to MFA in gasification-melting facilities was probably caused by carry-over of fine particles to the air pollution control system due to large gas volume. Finally, dilution effect was shown to have a significant effect on metal concentration in MFA.

Treatment and use of air pollution control residues from MSW incineration: An overview

“…Due to the high temperatures used, these methods are very efficient at destroying dioxins, furans and other toxic organic compounds (Sakai and Hiraoka, 2000). In fact, the number of vitrification plants in Japan increased significantly when dioxins had to be taken into account, according to the criteria of specially controlled waste established in 1999 (Jung et al, 2005). The final material has been considered suitable for reuse in practical applications, due to the fact that those thermal processes lead to the incorporation of elements of concern in the glass matrix through chemical bounding and/or encapsulation.…”

Obtención de vidrio a partir de residuos de la minería del estaño en Bolivia

“…Está técnica se ha estudiado ampliamente, obteniéndose vidrio y materiales vitrocerámicos comerciales (7)(8)(9)(10)(11)(12)(13)(14)(15). En otros casos la vitrificación ha sido utilizada para la estabilización y la reutilización de las cenizas volantes del proceso de incineración en centrales térmicas (16)(17)(18)(19)(20)(21)(22)(23)(24).…”

Characteristics of Melting Incinerator Ashes Using a Direct Current Plasma Torch

“…As for S1 and S3, the amounts of several heavy metals were even higher than those in raw ashes, such as Pb, Zn and Cu. The reason was that the high content of Chlorine in FA1 and FA3 impeded the stabilization of heavy metals [25][26][27] and the high value of basicity of FA1 and FA3 led to poor efficiency of vitrification [28]. It should be noted here, the total elemental mass balances were not considered in this study for some volatile metals such as Cd and Pb may evaporate to the atmosphere during molten stage.…”