title: Precious metals and rare earth elements in municipal solid waste--sources and fate in a Swiss incineration plant.
abstract: In Switzerland many kinds of waste, e.g. paper, metals, electrical and electronic equipment are separately collected and recycled to a large extent. The residual amount of municipal solid waste (MSW) has to be thermally treated before final disposal. Efforts to recover valuable metals from incineration residues have recently increased. However, the resource potential of critical elements in the waste input (sources) and their partitioning into recyclable fractions and residues (fate) is unknown. Therefore, a substance flow analysis (SFA) for 31 elements including precious metals (Au, Ag), platinum metal group elements (Pt, Rh) and rare earth elements (La, Ce, etc.) has been conducted in a solid waste incinerator (SWI) with a state-of-the-art bottom ash treatment according to the Thermo-Re® concept. The SFA allowed the determination of the element partitioning in the SWI, as well as the elemental composition of the MSW by indirect analysis. The results show that the waste-input contains substantial quantities of precious metals, such as 0.4 ± 0.2mg/kg Au and 5.3 ± 0.7 mg/kg Ag. Many of the valuable substances, such as Au and Ag are enriched in specific outputs (e.g. non-ferrous metal fractions) and are therefore recoverable. As the precious metal content in MSW is expected to rise due to its increasing application in complex consumer products, the results of this study are essential for the improvement of resource recovery in the Thermo-Re® process.
authors.affiliation: Baudirektion Kanton Zürich, Amt für Abfall, Wasser, Energie und Luft, Zurich, Switzerland. leo.morf@bd.zh.ch
authors.forename: Leo S
authors.initials: LS
authors.lastname: Morf
authors.forename: Rolf
authors.initials: R
authors.lastname: Gloor
authors.forename: Olaf
authors.initials: O
authors.lastname: Haag
authors.forename: Melanie
authors.initials: M
authors.lastname: Haupt
authors.forename: Stefan
authors.initials: S
authors.lastname: Skutan
authors.forename: Fabian
authors.initials: F
authors.lastname: Di Lorenzo
authors.forename: Daniel
authors.initials: D
authors.lastname: Böni
mesh_terms: D006046:Gold / Q000032:analysis; D017745:Incineration; D008670:Metals / Q000032:analysis; D008674:Metals, Rare Earth / Q000032:analysis*; D010984:Platinum / Q000032:analysis; D012834:Silver / Q000032:analysis; D062611:Solid Waste / Q000032:analysis*; D013557:Switzerland
chemical_list: D008670:Metals; D008674:Metals, Rare Earth; D062611:Solid Waste; D012834:Silver; D010984:Platinum; D006046:Gold