Addition of silane nanoparticles combined with mechanical activation for efficient reuse of sulfidic tailings for concrete construction

Abstract

This study proposes mechanical activation process to structurally modify the tailings containing high sulfide content. X-ray diffraction analysis indicated that the mechanical activation of the tailings caused a phase transformation in the samples, and the alite phase formed in the control sample transformed to the hatrurite phase in the sample containing 20% activated tailings. The presence of silane nanoparticles enhances the hydration process, forming hydrated calcium silicate gels, resulting in a substantial reduction in porosity. According to the results of the toxicity characteristic leaching procedure, the reduction of heavy metals leaching was observed as a conclusion of the combination of tailings activation and the addition of nano-silane. As a result of the bonding between silane nanoparticles and the hydration products, the sample incorporating 20% and 40% activated tailings demonstrated approximately 30% and 15% higher strength, respectively, compared to the control sample after a curing period of 90 days.