Variation in the Composition of Municipal Solid Waste Incineration Ash

• Type: Article in International Scientific Journal
• Date: 2024

Authors

B. Valentim (Author) FCUP; Guedes, A (Author) FCUP; Kuzniarska-Biernacka, I (Author) FCUP; Dias, J (Author) Other; Predeanu, G (Author) Other

Journal

Title: Minerals

Vol. 14

Final page: 1146

Publisher: MDPI

Indexing

ISI Web of Knowledge - 0 Citations

Scopus - 0 Citations

Other information

Authenticus ID: P-017-CCJ

DOI: 10.3390/min14111146

Abstract (EN): Unlike municipal solid waste bottom ash (MSWBA), fly ash (MSWFA) is landfilled due to its toxicity. However, MSWFA may also be a source of elements. Ash samples collected from a Portuguese MSW incinerator from different locations and over six months were analyzed. Their geochemical composition was normalized to the upper continental crust (UCC) and compared since metal enrichment may be used as an indicator for potential recovery. The potential recovery economic viability was also assessed for metals K, Sb, Cu, Pb, and Zn, considering the ore cut-off grade and minimum industrial grade (MIG) from Chinese geological and mineral industry standards. Compared to the global samples, only the Baghouse 1 FA size fraction's coarse fraction showed a slight enrichment (1- to 5-fold) in Bi, Nb, and Zr. After wet sieving, most trace elements were enriched in all fractions, but Sb, Bi, Pb, Zn, Ag, As, Cd, Sn, Se, and Hg were depleted in the coarse fractions and enriched in the fine ones. For Baghouse 1 samples collected over 6 months, the normalization to the UCC showed enrichment of Zn and Pb between 10x and 50x, Zr, Cu, In, and Se between 50x and 100x, and Ag, Mn, Cd, Sb, and Bi at more than 100x. Over six months, the Baghouse 1 FA soluble fraction ranged between 21 wt.% and 30 wt.%, and its precipitates comprised 27% CaO, 6% Na2O, and 9% K2O. The K concentration in the MSWFA was above the cut-off and the MIG, and K could be concentrated in precipitates via simple washing.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 28