Journal of Cleaner Production 357 (2022) 131971 Available online 27 April 2022 0959-6526/© 2022 Elsevier Ltd. All rights reserved. Reuse and stabilization of sulphide mine tailings as fne aggregate for construction mortar Anthony Andrews a, * , Edward F. Nyarko a , Albert A. Adjaottor a , Elsie Nsiah-Baaf b , Mark Adom-Asamoah c a Department of Materials Engineering, College of Engineering, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana b UTS-Boral Center for Sustainable Building, Botany, Australia c Department of Civil Engineering, College of Engineering, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana A R T I C L E INFO Handling Editor: M.T. Moreira Keywords: Sulphide mine tailings Stabilization River sand Fine aggregate Masonry mortar ABSTRACT The processing of low-grade sulphide gold ores generates a signifcant volume of tailings which impacts the environment. The reuse of sulphide mine tailings as a substitute for sand in construction mortar offers the ad- vantages of reducing costly tailings management whilst promoting sustainable construction. However, the acceptance of mine tailings as alternative sand for construction depends on its effective stabilization during use. In this study, hardened mortar cubes have been prepared by varying the substitution of river sand with sulphide mine tailings. The stabilization effects of cement, cement-lime and cement-pozzolana on sulphide mine tailings have been investigated. The water demand, slump behaviour, bulk density, water absorption, compressive strength, and X-ray diffraction (XRD) were examined to observe the physical and mechanical properties of the mortars. The water demand and bulk density decreased whilst the slump value and water absorption increased with increased tailings replacement. The highest 28-day compressive strength of 12.2 MPa was achieved at 25% tailing replacement with a cement binder. Cement proved to be the best binder for the stabilization of the tailings which was followed by cement-pozzolana and cement-lime respectively. 1. Introduction Mining generates huge quantities of solid wastes in the form of waste rocks and mine tailings (Benarchid et al., 2019). The mine tailings are fned grained slurries after processing the ore (Simonsen et al., 2020). As the high-grade ores get depleted, the use of technology has enabled the processing of low-grade ores thus increasing the volume of tailings generated (Yang et al., 2021). Tailings are often stored for short to medium term in impoundments while waste rocks are often stored in gravity pits. Tailings, having gone through metallurgical processing such as milling and leaching, often contain harmful concentrations of cyanide, heavy metals and other chemical contaminants. Improper disposal of the tailings poses a threat to the environment including Acid Mine Drainage (AMD) (Dold, 2014; Benarchid et al., 2019), the collapse of a storage facility (Macklin et al., 2003), and soil contamination (Simonsen et al., 2020). Environmental regulations are imposing stricter limitations on mine tailings storage practices (Xiaolong et al., 2021). Additionally, the storage of mine tailing in impoundments requires costly maintenance (Kiventer¨ a et al., 2016). Proper management and utilization of mine tailings have the potential to contribute to environ- mental protection whilst enjoying some economic benefts (Qi and Fourie, 2019). Recently, attempts have been made to reuse and recycle mine tailings (Argane et al., 2016) and waste rocks (Adom-Asamoah and Afrifa, 2010) as aggregates in concrete, cementitious material (Simon- sen et al., 2020) or cement paste backfll (Tariq and Yanful, 2013; Qi and Fourie, 2019) applications. It has been reported that some mine tailings contain clay minerals and can be used as a component in alkali-activated blends (Kotwica et al., 2018a). Thus the reuse of mine tailings in con- struction can either partially replace cement or act as fne aggregates in concrete. For instance, a 30% binder replacement with gold mine tail- ings as a cementitious material was found to reduce CO 2 emissions from cement production by about 22% (Ince, 2019). The utilization of mine tailings in construction constitutes a paradigm shift in tailings man- agement techniques that can reduce volumes of mine wastes whilst mitigating their environmental impacts. The characteristics of tailings markedly depend on the mineralogy of the ore deposit and the * Corresponding author. E-mail address: aandrews.coe@knust.edu.gh (A. Andrews). Contents lists available at ScienceDirect Journal of Cleaner Production journal homepage: www.elsevier.com/locate/jclepro https://doi.org/10.1016/j.jclepro.2022.131971 Received 2 December 2021; Received in revised form 9 March 2022; Accepted 22 April 2022