Preparation of environmental-friendly cementitious material from red mud and waste glass sludge by mechanical activation

There is an increasing requirement to manage large amounts of solid industrial waste, such as red mud (RM) and waste glass sludge (WGS), which pose potential environmental hazards to human health. The purpose of this study was to improve the reactivity of the red mud with mechanical activation. The reactivity was measured by the dissolution efficiency of silicon and aluminium in alkaline solution, the strength index, and the strength of the geopolymer. The optimal condition: WGS addition is 30 wt%; grinding time is 20 min; specific surface area reached 24.65 m2/g; the compressive strength of the geopolymer came to 15.98 Mpa curing for 28 days. XRD, FTIR and XPS were applied to investigate the structural transformation in the process. The environmental characterisation showed a significant leaching concentration of heavy metal(loid)s such as Cr, Zn, Cu, and Mn, which decreases with longer curing periods. The carbon emission results showed that the precursor exhibited enormous potential in energy conservation and emission reduction. The study results demonstrate that cementitious material from two solid waste materials can substantially lower heavy metal leaching values whilst also providing economic benefits. This synthesis pathway can be attained through recycling the two solid wastes, resulting in geopolymers that exhibit potential for a variety of applications. •Incorporating waste glass sludge vastly enhances the distribution of particle sizes.•The dissolution efficiency of Si and Al was enhanced by the inclusion of waste glass sludge.•A greater activity index of RM was observed post-grinding.•All heavy-metals contained in the precursor could reach the leaching toxicities' standards.