Mining and metallurgical wastes: a review of recycling and re-use practices

Abstract

Mining is a complex process involving activities that range from exploration through mine development, mineral beneficiation, metal extraction, smelting, refining, reclamation, and remediation (Bian et al., 2012; Ndlovu, Simate, and Matinde, 2017). In the process of extracting the metal values, these activities produce significant amounts of wastes, typically consisting of (1) solid wastes in the form of waste rock, dusts, sludges, and slags, (2) liquid wastes in the form of waste water and effluents, and (3) gaseous emissions. In South Africa, mining and metallurgical wastes constitute one of the biggest challenges to the environment. If not managed properly, the anthropogenic effects of these mining and metal extraction activities can result in irreversible damage to the environment and a hazard to humans. In South Africa, in particular, these types of wastes are usually disposed of in landfills, thereby creating serious environmental and health challenges for communities. Mitigating the effects of such mining, metallurgical, and metal manufacturing processes requires a holistic waste management approach that incorporates reduction in the amount of waste

Ironmaking and Steelmaking Slags as Sustainable Adsorbents for Industrial Effluents and Wastewater Treatment: A Critical Review of Properties, Performance, Challenges and Opportunities

“…Metallurgical slags play indispensable roles in the efficient extraction and refining of metals [20][21][22]. They are formed from the reaction between fluxes, intentionally added as part of the furnace charge, and gangue minerals in ores during the smelting process, or from the reaction between fluxes and dissolved impurities during refining [20][21][22]. Fluxing produces a low liquidus and complex slag melt which is immiscible with the metal and/or alloy phases, and is thus easily separated during tapping [20,22].…”

“…They are formed from the reaction between fluxes, intentionally added as part of the furnace charge, and gangue minerals in ores during the smelting process, or from the reaction between fluxes and dissolved impurities during refining [20][21][22]. Fluxing produces a low liquidus and complex slag melt which is immiscible with the metal and/or alloy phases, and is thus easily separated during tapping [20,22]. These materials not only play a role in controlling the metallurgical efficiency of smelting and refining processes, but are also critical in improving the energy efficiency [23].…”

“…Currently, large volumes of solidified slags are disposed of in landfills. However, the disposal of slags in landfills creates long-term environmental challenges [22][23][24]. In order to mitigate the anthropogenic effects of process slags, it is therefore imperative to explore alternative utilisation options and to reduce the amounts that end up in landfills [22][23][24][25].…”

“…However, the disposal of slags in landfills creates long-term environmental challenges [22][23][24]. In order to mitigate the anthropogenic effects of process slags, it is therefore imperative to explore alternative utilisation options and to reduce the amounts that end up in landfills [22][23][24][25]. Thus, the alternative use of slags as sustainable and low-cost adsorbents is one such approach that can increase the valorisation potential of these materials [3,4,[22][23][24][25].…”

Mining Rock Wastes for Water Treatment: Potential Reuse of Fe- and Mn-Rich Materials for Arsenic Removal

“…In mining companies, the cost of waste handling and storage can represents a financial loss around 1.5-3.5% of total costs [5]. The transformation of mining wastes is promoted to pursue a zero-waste circular model economy by evaluating solutions for their re-use [6]. The chemical composition and geotechnical properties of the source rock determine which uses are most appropriate and whether reuse is economically feasible.…”