Synthesis, characterization, and efficacy of alkali-activated materials from mine tailings: A review

Abstract

Annually, over 5 billion metric tons of tailings are produced worldwide as byproducts of mining processes, posing significant environmental risks due to their potential to pollute and disrupt ecosystems. Concurrently, the production of portland cement (PC), the primary binder in cementitious materials is a major contributor to global anthropogenic carbon dioxide emissions. With the escalating demand for PC, a corresponding surge in carbon emissions is inevitable. Alkali-activated materials (AAMs) present a greener alternative to PC, given their production primarily utilizes industrial wastes. Traditional precursors for AAMs, such as fly ash and slag, however, are not universally available—Canada, for instance, faces a scarcity of fly ash for AAM production. In response to the dual challenges of managing mine tailings and reducing PC’s environmental footprint, this review proposes the innovative use of mine tailings as an alternative binder to PC. This paper offers a thorough examination of mine tailings’ properties, methodologies to enhance their suitability for AAM synthesis, and an analysis of AAMs produced from diverse tailing sources. Additionally, this paper explores the associated challenges and future prospects, providing a rounded overview of this promising avenue in sustainable construction materials.