Microstructure and self-solidification/stabilization (S/S) of heavy metals of nano-modified CFA-MSWIFA composite geopolymers

摘要

Nano-modified composite geopolymers were successfully prepared from municipal solid waste incineration fly ash (MSWIFA) and class C fly ash (CFA). The results indicate that both nano-SiO_2 and nano-γ-Al_2O_3 have a good modification effect on geopolymer, of which nano-SiO_2 has a better performance than nano-γ-Al_2O_3. The optimum content of nano-SiO_2 and nano-y-Al_2O_3 are 1.5％ and 2.0％, respectively. XRD shows that there is no new phase emerging after adding a small amount of nanomaterials. By FT-IR and SEM, it means that nanomaterials facilitate the reaction of geopolymer, making the modified geopolymer more compact. BET shows nano-SiO_2 especially modifies the pore distribution and pore structure of geopolymers. Additionally, nanomaterials have an improvement to the solidification/stabilization (S/S) of heavy metals.