University of Oulu

Vitalii Ponomar, Katja Ohenoja, Mirja Illikainen, Optimizing activating solution and environmental leaching characteristics of Fe-rich alkali-activated Zn slag, Journal of Hazardous Materials, Volume 445, 2023, 130575, ISSN 0304-3894,

Optimizing activating solution and environmental leaching characteristics of Fe-rich alkali-activated Zn slag

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Author: Ponomar, Vitalii1; Ohenoja, Katja1; Illikainen, Mirja1
Organizations: 1Fibre and Particle Engineering Research Unit, University of Oulu, Pentti Kaiteran katu 1, 90014 Oulu, Finland
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 8.7 MB)
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Language: English
Published: Elsevier, 2022
Publish Date: 2023-08-16


In this work, slag from Zn processing was used to produce Fe-rich alkali-activated materials (AAMs) with low environmental impact. The interconnection between activating solution composition, compressive strength, and environmental leaching characteristics was assessed. The reaction products characterised with FT-IR, XRD, and SEM-WDS were represented by Fe-rich C-S-H gel of tobermorite-related structure. The local aggregation of Na and Mg suggests the minor role of these elements in the reaction product. The reaction product seems to be undependable on the alkali cation used in the solution. Besides, the hardening reaction took place fast, and the maximum compressive strength of 70 MPa was determined only after 1 day after mixing with silicate solutions. To decrease the economic and environmental impact, 1) simultaneous decreasing Na₂O/slag and SiO₂/slag ratios or 2) decreasing SiO₂/Na₂O ratio can be applied without prominent deterioration of the strength. Environmental leaching results showed an increase in the leached content of several metal(loid)s (e.g., As, Mo, Cr, Sb, Se, V) as a results of alkali activation, but also some immobilization effect for Ba, Pb and Zn. Also, the presence of liquid silica in the activating solutions or higher water content reduced the leaching of some elements.

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Series: Journal of hazardous materials
ISSN: 0304-3894
ISSN-E: 1873-3336
ISSN-L: 0304-3894
Volume: 445
Pages: 1 - 13
Article number: 130575
DOI: 10.1016/j.jhazmat.2022.130575
Type of Publication: A1 Journal article – refereed
Field of Science: 216 Materials engineering
Funding: This work was done under the auspices of the TOCANEM (Towards Carbon Neutral Metals) project which was funded by Business Finland and the following Finnish companies: Boliden Harjavalta Oy, Boliden Kokkola Oy, Fortum Waste Solutions Oy, Freeport Cobalt Oy, Kivisampo Oy, Outokumpu Stainless Oy, Outotec (Finland) Oy, Owatec Group Oy, Sapotech Oy, Metsä Group Oy, Ovako Imatra Oy, and SSAB Europe Oy.
Copyright information: © 2022 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (