Characterisation and partition of valuable metals from WEEE in weathered municipal solid waste incineration bottom ash, with a view to recovering

S. Pérez-Martínez, J.  Giro-Paloma, A. Maldonado-AlamedaJ. Formosa, I. QueraltJ.M. Chimenos

https://doi.org/10.1016/j.jclepro.2019.01.313

Journal of Cleaner Production, 2019, 218, 61-68

Quartile Q1, Impact 7.246

As the demand for critical and valuable metals increases due to industrial developments, especially in electronics and high-technology industries, the search for novel and sustainable sources grows in significance. Incinerated municipal solid waste (MSW) is a potential source of valuable metals, since a lot of waste from electrical and electronic equipment (WEEE) is not recycled properly and is managed together with the refuse fraction of MSW, which is often landfilled or incinerated. Bottom Ash (BA) is the main by-product of incinerated MSW, which has been characterized to assess the potential recovery of valuable metals. The determination of the total amount of valuable metals (Ag, Al, Au, Be, Co, Cu, Ga, Ge, In, Ir, Li, Ni, Pd, Pt, Sb, Ta, and W) in seasonal samples of weather bottom ash (WBA) was performed by a total acid digestion followed by a chemical analysis. Besides, a sequential extraction procedure (SEP) is conducted to define their partition. The characterisation has shown that the content of valuable metals in the incineration WBA, which was highest in the 0e2mm fraction was much lower than in concentrated ores commonly used as primary sources. Moreover, the SEP showed little potential for the valorisation of most of the metals, as they are embedded in or bound to a silicic matrix or sintered metal oxides, and so their extraction requires strong-acid digestion or a highly oxidizing environment. This work contributes to the use of residual sources as secondary resources and to the correct management of the end-of-life electrical and electronic equipment.

Particle size distribution (PSD) of the seasonal weather bottom ash (WBA) samp les.

Average of metal content in each fraction of the seasonal WBA samples. Particle size fractions reportai in mm.

Partition and tcfal content of valuable metals (ln. Au Pd. Va. Be Ag and W) extractai from WBA sample collet«i on July. in accordance with each step of the sequential extraction and total digestion procedures. Pardcle size fractions reported in

Parition and total content of valuable metals (Ga. Li. Sb. Co. Ni Cu and Al) extracted from WBA collected on July, in accordance with each step of the sequential extraction and tcral digestion procaiures, Particle size fractions reported in

Funding

The research leading this project has received funding from the Spanish Government (BIA2017–83912- C2–1-R). This work has been partially funded by a Catalonian research Grant (FI-DGR 2017).

Research category: Environment