Recovery of zinc and lead from fly ash from ash-melting and gasification-melting processes of MSW--comparison and applicability of chemical leaching methods.
Waste Manag
; 27(1): 69-80, 2007.
Article
en En
| MEDLINE
| ID: mdl-16488594
Fly ash generated from MSW ash-melting and gasification-melting plants, known as Melting Furnace Fly Ash (MFA), contains considerable amounts of heavy metals such as Pb and Zn. These metals can be recovered using a smelting furnace after "pre-treatment" for removal of unnecessary elements such as Cl, Sn and Si. Chemical methods have been studied for pretreatment in the past. However, they have been discussed only with regard to treatment cost and the concentration of Pb and Zn recovered, but neither applicability to various types of MFA nor the environmental impact have been considered. In this study, acid, alkaline and ammonia/chloride leaching methods were compared from the standpoints of: (1) applicability to MFA, (2) concentration of Pb and Zn recovered, (3) treatment cost, and (4) environmental impact. Twenty-three samples of MFAs were collected and classified into 4 types based on element contents. A Pb and Zn recovery experiment was conducted for the representative MFA of those types. The results showed: (1) MFA from gasification-melting plants cannot be treated by chemical methods; (2) the other MFA can be treated to an acceptable quality by existing smelting furnaces; (3) only MFA from electric resistance ash-melting plants can be treated easily by the water washing method; and (4) alkaline and ammonia/chloride leaching methods were more effective than acid leaching.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Zinc
/
Carbono
/
Eliminación de Residuos
/
Conservación de los Recursos Naturales
/
Material Particulado
/
Plomo
Tipo de estudio:
Evaluation_studies
Límite:
Humans
Idioma:
En
Revista:
Waste Manag
Asunto de la revista:
SAUDE AMBIENTAL
/
TOXICOLOGIA
Año:
2007
Tipo del documento:
Article
País de afiliación:
Japón
Pais de publicación:
Estados Unidos