Speciation of toxic pollutants in Pb/Zn smelter slags by X-ray Absorption Spectroscopy in the context of the literature

Dan Ting Chen; Amitava Roy; Yu Qian Li; Anna Bogush; Wing Yin Au; Julia A Stegemann

doi:10.1016/j.jhazmat.2023.132373

Speciation of toxic pollutants in Pb/Zn smelter slags by X-ray Absorption Spectroscopy in the context of the literature

J Hazard Mater. 2023 Oct 15:460:132373. doi: 10.1016/j.jhazmat.2023.132373. Epub 2023 Aug 23.

Authors

Dan Ting Chen¹, Amitava Roy², Yu Qian Li¹, Anna Bogush¹, Wing Yin Au¹, Julia A Stegemann³

Affiliations

¹ Department of Civil, Environmental and Geomatic Engineering (CEGE), University of College London (UCL), Chadwick Building, Gower Street, London WC1E 6BT, UK.
² Louisiana State University Center for Advanced Microstructures and Devices, Baton Rouge, LA 70806, USA.
³ Department of Civil, Environmental and Geomatic Engineering (CEGE), University of College London (UCL), Chadwick Building, Gower Street, London WC1E 6BT, UK. Electronic address: j.stegemann@ucl.ac.uk.

PMID: 37703727
DOI: 10.1016/j.jhazmat.2023.132373

Abstract

Pb/Zn smelter slag is a hazardous industrial waste from the Imperial Smelting Process (ISP). The speciation of zinc, lead, copper and arsenic in the slag controls their recovery or fate in the environment but has been little investigated. X-ray Absorption Spectroscopy (XAS) was applied to this complex poorly crystalline material for the first time to gain new insights about speciation of elements at low concentration. Zn, Cu, As K-edge and Pb L3-edge XAS was carried out for a Pb/Zn slag from a closed ISP facility in England, supported by Fe, S and P K-edge XAS. Results are presented in the context of a full review of the literature. X-ray fluorescence showed that concentrations of Zn, Pb, Cu and As were 8.4, 1.6, 0.48 and 0.45 wt%, respectively. Wüstite (FeO) was the only crystalline phase identified by X-ray diffraction, but XAS provided a more complete understanding of the matrix. Zn was found to be mainly present in glass, ZnS, and possibly solid solutions with Fe oxides; Pb was mainly present in glass and apatite minerals (e.g., Pb₅(PO₄)₃OH); Cu was mainly speciated as Cu₂S, with some metallic Cu and a weathering product, Cu(OH)₂; As speciation was likely dominated by arsenic (III) and (V) oxides and sulfides.

Keywords: Imperial smelting furnace; Mineralogy; Smelter slag; Toxic contaminants; Utilization.