The global challenge of effectively using and treating solid wastes in an environmentally sustainable way is significant. This study explores the creation of ternary low-carbon gelling materials made from red mud (RM), mineral powder (MP), and soda residue (SR). Using techniques such as SEM-ED, XRD, and FTIR, the microstructure of the red mud–mineral powder–alkaline slag (RM-MP-SR) mixture was analyzed, and the mechanical and physical properties of the material, as well as the leaching behavior of heavy metals, were investigated. The MRS16 sample, containing a 16% SR replacement, exhibited the best properties: compared with the control sample MRS0 (without replacement), its 28-day compressive strength increased by 43.7% to 51.3 MPa, the drying shrinkage rate decreased by 43.2%, and the mass loss rate reduced by 73.9%. After 100 freeze–thaw cycles, the mass loss was only 3.7%. The addition of SR can decrease the porosity in ternary materials, enhancing their mechanical properties; this is mainly due to SR promoting the increase in C-S-H, C-A-S-H gel, and ettringite. Meanwhile, MRS16 showed excellent freeze–thaw resistance, and the leaching levels of Cu, As, Pb, Cr, and Ni were within China’s non-hazardous limits. This study emphasizes the potential of combining RM, MP, and SR, providing useful scientific and theoretical insights for the joint use of alkaline, silica–aluminum, and calcium-based solid wastes.
Zhao et al. (Thu,) studied this question.