<p>In order to address the problem of iron ore tailings resource utilization and develop broadband electromagnetic wave absorption materials, this study prepared iron ore tailings foam concrete by synergistic excitation of sodium hydroxide and liquid water glass, and added nano-silicon carbide to enhance electromagnetic wave absorption performance. The results showed that when the alkali equivalent was 0.4&#xa0;wt.%, the percentage of 0–200&#xa0;μm pores was 51.64%, which was 11.01% higher than that of the control group. When water glass was used as an alkali activator, the proportion of 0–200&#xa0;μm pores increased to 65.10%, and the proportion of 600–800&#xa0;μm macropores was controlled at 1.65% in the MS1.0 group with a modulus of 1.0. The material exhibits excellent electromagnetic wave absorption performance, with a reflection loss of –49.17&#xa0;dB and an effective bandwidth of 6.0&#xa0;GHz (12–18&#xa0;GHz), completely covering the Ku band. The performance improvement is owing to the synergistic effect of nano-silicon carbide conductive network and silicate gel interface polarization. In addition, the material also exhibited excellent mechanical properties, with a compressive strength of 5.32&#xa0;MPa and a flexural strength of 2.42&#xa0;MPa, which were 166% and 160% higher than those of the control group, respectively. These results indicate that the developed iron ore tailings foam concrete has great potential for applications in electromagnetic wave absorption.</p> Graphical Abstract <p></p>