Coal gasification fine slag doped with Fe3O4: High-performance electromagnetic-wave absorbers

The pursuit of electromagnetic absorbers with high-performance characteristics has led to a growing appreciation for easily prepared and environmentally friendly methods. In this study, heterostructured multi-interface Fe3O4@Coal gasification fine slag (CGFS) composites were directly prepared via coprecipitation of Fe3O4 nanoparticles (NPs) and untreated coal gasification fine slag. The composite material was subjected to analysis of its magnetic properties, crystal structure, composition, electromagnetic parameters, and morphology, resulting in the determination that the material achieved a minimal reflection loss (RLmin) of –28.10 dB at 10.00 GHz at a thickness of 2.7 mm (Fe3O4@FS-1). Broadband microwave attenuation covers 4.00 GHz at a thickness of 1.7 mm (Fe3O4@FS-2). The exceptional performance of Fe3O4@CGFS composites in absorbing electromagnetic waves (EMWs) is attributed to a combination of factors, including appropriate impedance matching, dielectric and magnetic losses, and a multi-interface design, resulting in a synergistic effect. The CST simulation clearly indicated that the Fe3O4@FS-1 composite is capable of significantly reducing the radar cross-section value under realistic conditions. The corrosion resistance test results show that the Fe3O4@CGFS composites has good chemical stability. Overall, the high graphite residual carbon content in CGFS provides a foundation for reducing the preparation conditions of EMW absorbers while maintaining superior electromagnetic-wave absorption and dielectric losses, thereby expanding the high-value utilization of CGFS.