Utilization potential of mine tailings in geopolymers: Physicochemical and environmental aspects

Abstract

The mining industry produces a large amount of mine waste rock and tailings, which pose a severe threat to the environment. The most common way for the disposal of these industrial wastes is dumping at sites, which contributes to soil degradation and water pollution, and also covers the useful land. Recycling of mine tailings (MTs) in raw material - intensive applications presents a good alternative to manage the waste generated from mining and mineral processing industries. The geopolymer technology provides a green solution to the utilization of MTs, avoiding its negative environmental impacts. This paper is the first part of the review which summarizes the physicochemical and environmental aspects of different types of MTs, as well as the technological aspects of the preparation of geopolymers (GPs) based on them. The work scrutinizes potential environmental and socio-economic risks of the mining industry associated with the accumulation of tailings. The issues of MTs toxicity that should be taken into account when developing methods for disposal of tailings in geopolymers are touched upon. The features of the chemical and mineral composition of tailings used in geopolymers, as well as their physical properties, are systematized and scrutinized. Methods of utilizing MTs as precursors of GPs or aggregates described in the scientific literature, as well as general patterns of the geopolymerization process are discussed. Finally, the key issues in this area that require additional research are highlighted.