The synthesis of an iron tailings-based geopolymer with synergistic electromagnetic wave consumption property

In this study, combination of wave absorption materials with different loss mechanisms are added into iron ore tailings-blast furnace slag (IOT-BFS) based geopolymers. The employed materials are hollow glass microsphere (HGM), carbon nanotubes (CNT) and carbonyl iron powder (CIP). Microstructures of the geopolymers are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and concrete porous structure analyzer. Conductivity and electromagnetic absorption property of the geopolymers are measured by a conductivity tester and a vector network analyzer (VNA). As increasing the content of wave absorption materials, compressive strength of the geopolymer decreased from 60.5 to 33.8 MPa. Compared with geopolymers containing HGM and CNT, wave absorption band below -5 dB of the geopolymers with HGM and CIP was wider, particularly at frequencies below 7 GHz, due to the synergism of space and magnetic loss. Its absorption bandwidth with the reflection loss less than -5 dB reaches 15.6 GHz. This study gives a clue for preparation of geopolymers with satisfactory electromagnetic wave absorption properties in the utilization as construction materials.