Recycling mine tailings as precursors for cementitious binders – Methods, challenges and future outlook

Abstract

Increase in demand for mineral commodities such as coal, copper, iron, aluminium, gold, tungsten, zinc etc., has led to higher quantity of mineral waste produced such as solids, crushed rocks, overburden soil and tailings. The fine-grained mineral waste left after removal of valuable material from ore is called mine tailing and is one of the major wastes of the mining processes. Mineral wastes from mines, quarries and excavations are typically rich in SiO2, Al2O3, CaO and Fe2O3. This chemical composition makes them very attractive candidates to be used in the production of construction materials, as these oxides are also the main constituents of cement as well as of key alkali-activated binders. This contribution aims to provide a comprehensive overview of the nature of mine tailings, the current state-of-the-art in their utilisation in cementitious binders and the future potential. A rational summary of limitations associated with use of mine tailing in cementitious binder due to its low reactivity and potential solutions to overcome it is also provided. The study concludes with how the use of mine tailings in cementitious binder could benefit in achieving the global sustainability goals.