title: Metal distribution characteristic of MSWI bottom ash in view of metal recovery.
abstract: Bottom ash is the major by-product of municipal solid waste incineration (MSWI), and is often reused as an engineering material, such as road-base aggregate. However, some metals (especially aluminum) in bottom ash can react with water and generate gas that could cause expansion and failure of products containing the ash; these metals must be removed before the ash is utilized. The size distribution and the chemical speciation of metals in the bottom ash from two Chinese MSWI plants were examined in this study, and the recovery potential of metals from the ash was evaluated. The metal concentrations in these bottom ashes were lower than that generated in other developed countries. Specifically, the contents of Al, Fe, Cu and Zn were 18.9-29.2, 25.5-32.3, 0.7-1.0 and 1.6-2.5g/kg, respectively. Moreover, 44.9-57.0wt.% of Al and 55.6-75.4wt.% of Fe were distributed in bottom ash particles smaller than 5mm. Similarly, 46.6-79.7wt.% of Cu and 42.9-74.2wt.% of Zn were concentrated in particles smaller than 3mm. The Fe in the bottom ash mainly existed as hematite, and its chemical speciation was considered to limit the recovery efficiency of magnetic separation.
authors.affiliation: State Key Laboratory of Pollution Control & Resource Reuse, Tongji University, Shanghai 200092, China; Institute of Waste Treatment and Reclamation, Tongji University, Shanghai 200092, China. Electronic address: 258299331@163.com.
authors.forename: Yi
authors.initials: Y
authors.lastname: Xia
authors.affiliation: Institute of Waste Treatment and Reclamation, Tongji University, Shanghai 200092, China; Center for the Technology Research and Training on Household Waste in Small Towns & Rural Area, Ministry of Housing and Urban-Rural Development of China (MOHURD), Shanghai 200092, China.
authors.forename: Pinjing
authors.initials: P
authors.lastname: He
authors.affiliation: Institute of Waste Treatment and Reclamation, Tongji University, Shanghai 200092, China; Center for the Technology Research and Training on Household Waste in Small Towns & Rural Area, Ministry of Housing and Urban-Rural Development of China (MOHURD), Shanghai 200092, China.
authors.forename: Liming
authors.initials: L
authors.lastname: Shao
authors.affiliation: State Key Laboratory of Pollution Control & Resource Reuse, Tongji University, Shanghai 200092, China. Electronic address: zhanghua_tj@tongji.edu.cn.
authors.forename: Hua
authors.initials: H
authors.lastname: Zhang
mesh_terms: D017745:Incineration / Q000379:methods*; D019216:Metals, Heavy / Q000032:analysis*; D059027:Recycling / Q000379:methods*; D062611:Solid Waste / Q000032:analysis*
chemical_list: D019216:Metals, Heavy; D062611:Solid Waste
keywords: Bottom ash; Metal recovery; Metal speciation; Municipal solid waste incineration; Size distribution