Design of all solid waste red mud-based cementitious materials based on the simplex centroid method

As alumina production grows, the focus on red mud, a highly alkaline and hazardous industrial waste, intensifies. This study seeks to lower energy use and environmental pollution by replacing traditional cement with red mud and other solid wastes, promoting the resourceful use of waste. Employing a simplex centroid method, the study proposes a new design for solid waste cementitious materials using red mud (RM), steel slag (SS), fly ash (FA), and Phosphogypsum (PG), named the RSF+P series, transforming red mud into an eco-friendly engineering material. The study encompasses mixture design, data analysis, diverse testing methods like TG-DTG, XRD, FTIR, SEM-EDX, and evaluation of pollutant leaching's environmental impact in composite materials. Experimental findings show that RSF+P series has favorable qualities, including suitable setting times (initial: 188 min, final: 437 min), high 28d UCS (11.89 MPa), and low permeability (0.91x10- 6). Additionally, it significantly lowers heavy metal and sodium ion concentrations, aiding environmental sustainability by meeting standard limits. eBalance analysis reveals that compared to traditional cement, the preparation and application of RSF+P decrease primary energy demand by 83.83% and environmental load by 84.78%. This study is crucial for addressing red mud disposal and environmental pollution, offering new insights on using similar wastes.