Geopolymer synthesis using garnet tailings from molybdenum mines

Abstract

Garnet tailings obtained in large quantities from molybdenum ore beneficiation are regarded as industrial waste, which not only occupies large areas of land but also causes environmental issues and ecological fines. Preparing garnet tailings based geopolymers (GTGs) is one of the efficient methods to recycle and utilize garnet mine tailings. In this work, geopolymers were synthesized using garnet tailing (GT) and metakaolin (MK) as the main precursors and sodium silicate as the alkali-activation agent. The effect of MK and alkali activator dosage, as well as curing temperature on the compression strength of GTGs were analyzed in detail. Results showed that the maximum strength (46 MPa, 3 days) was reached at a 20 wt % MK dosage with 35% sodium silicate addition cured at room temperature. The microstructure and phase composition of GTGs were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier-transform infrared spectroscopy (FTIR), which confirmed the formation of an amorphous geopolymer gel. Lastly, it can be concluded that the garnet tailing is a promising material for geopolymer production, as an alternative for its utilization.