Development of geopolymer from gold mine tailings utilizing Taguchi robust design

This study focuses on the production of geopolymers incorporating gold mine tailings (GMTs) as the primary aluminosilicate source. Utilizing the Taguchi experimental design, the effects of varying the amounts of sodium silicate (Na2SiO3), rice husk ash (RHA), and copper (Cu) on the compressive strength and apparent porosity of the geopolymers were investigated. The results demonstrated that increasing Na2SiO3 to 10 wt% and RHA to 20 wt% led to a significant increase in compressive strength, peaking at 3.22 MPa, while elevated Cu levels correlated with decreased strength owing to increased apparent porosity. Analysis of variance highlighted all three parameters as significant signal factors that influenced the compressive strength. However, only the amounts of Cu and RHA showed a significant effect on the material's apparent porosity, with a maximum of 7.3% increased porosity. Signal-to-noise ratio analysis identified Na2SiO3 and Cu as critical factors in minimizing variations of compressive strength. Microstructural analysis via x-ray diffraction confirmed geopolymerization, with the surface morphology displaying grain homogeneity as seen in scanning electron microscope. These findings underscore the potential of GMTs incorporation in geopolymers, emphasizing their sustainability in construction materials and non-load bearing applications, as well as their implications for environmental impact mitigation.