Mine wastes based geopolymers: A critical review

Abstract

The quantities of waste rocks and tailings generated by the mining industry have been increased in the last decades. The accumulation and the surface storage of these mine wastes represents a real challenge in terms of environmental and health issues. Thus, the recycling and valorization of these mine wastes is one of the most effective ways of reducing their volume and mitigating their negative environmental impact. Among the recent and sustainable management strategies, geopolymerization technology offers many advantages, (i) the stabilization of polluted/inert mine wastes in the geopolymer matrix, (ii) valorization of a large volume of wastes in the construction sector and consequently minimization of environmental impacts, and finally (iii) the significant reduction of greenhouse gas emissions generated by the use of ordinary Portland cement (OPC) in the construction sector. This paper is intended to present an updated and critical review of the existing literature about mine wastes based geopolymers, by focusing mainly on the mechanical performances of each type of waste. The fundamentals of geopolymers synthesis and the effect of metakaolin substitution by mine wastes are investigated. The influence of the chemical composition of mine wastes was linked to the compressive strength. Results of recent studies showed that geopolymeric materials elaborated using mine wastes presented similar or better mechanical, physical, and durability properties compared to OPC.

Keywords

• Valorization
• Mine wastes
• Wastes management
• Geopolymers