The comprehensive utilization of tailings is one of the key aspects of green development in the mining industry, and the preparation of geopolymers by tailings holds significant promise. Due to the low reactivity of tailings, thermal-alkali activation can effectively enhance their reactivity, thereby optimizing the performance of geopolymers. To characterize the changes in phase composition and chemical bonds during the activation process, exploring the activation mechanism, X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR) were employed. The results indicate that the 7-day compressive strength of thermally-alkali-activated tailings geopolymers can reach up to 15.58 MPa, representing a more than tenfold increase compared to non-activated samples. The compressive strength of the geopolymers improves with the rise of alkali content, calcination temperature and calcination duration. During the thermal-alkali activation process, muscovite in the tailings undergoes structural distortion through group substitution and is converted into an amorphous phase. The alkali content and calcination temperature has a notable impact on the activation effect. The research findings can provide a theoretical foundation for the selection and activation of tailings in geopolymer preparation.

Geopolymer  /  Copper tailings  /  Thermal-alkali activation  /  Compressive strength  /  Activation mechanism