Title: Characterisation study of different electric arc furnace steel slags for usage in wastewater treatment

Authors: Tedlaye Forsido; Rob I. McCrindle; Jannie Maree; Lizzy Mpenyana-Monyatsi

Addresses: Department of Environmental Water and Earth Science, Tshwane University of Technology, 175 Nelson Mandela Avenue, 0001 Pretoria, South Africa ' Department of Environmental Water and Earth Science, Tshwane University of Technology, 175 Nelson Mandela Avenue, 0001 Pretoria, South Africa ' Department of Environmental Water and Earth Science, Tshwane University of Technology, 175 Nelson Mandela Avenue, 0001 Pretoria, South Africa ' Department of Environmental Water and Earth Science, Tshwane University of Technology, 175 Nelson Mandela Avenue, 0001 Pretoria, South Africa

Abstract: In this study mineralogical, morphological, phase structure and chemical composition of electric arc furnace slags is presented. The result indicated that both types of slag contain the same types of minerals and metals in different percentage. The most common mineral forms were akermanite, ghelenite, merwinite, monticellite, calcite, ferrite and quartz. It was found that EAFD contains a larger proportion of the readily soluble mineral forms, less concentration of hazardous metals and a larger percentage of alkali (greater than 94% as CaCO₃). Hence, EAFD is a better choice for acidic wastewater treatment for neutralisation as well as removal of metals. It also contains less concentration of hazardous metals. It contains more than 94% lime measured as CaCO₃, which is used for neutralisation and removal of hazardous metals from effluents by raising its pH to a level where they form stable precipitates at a raised pH.

Keywords: electric arc furnace slag; EAFS; akermanite; ghelenite; merwinite; monticellite; wastewater; treatment.

DOI: 10.1504/IJEWM.2025.144253

International Journal of Environment and Waste Management, 2025 Vol.36 No.2, pp.243 - 251

Received: 17 Jul 2021
Accepted: 06 Jul 2022
Published online: 03 Feb 2025 *

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