Novel ceramic-based microwave absorbents derived from gangue†
To realize the resource utilization of gangue, the gangue was effectively recycled to prepare ceramic-based microwave absorbents. The synthesis process mainly involved the pelletizing of gangue, the loading of precursor solution and in situ carbothermal reduction. Furthermore, the obtained FeG composites were measured and characterized in terms of the phase composition, microstructure and performance. The results showed that FeG500 exhibited excellent electromagnetic absorbing ability, the effective absorption bandwidth remained at 4.1 GHz and the minimum reflection loss value reached −41.9 dB correspondingly when the coating thickness was 2 mm. This mainly arises from the interfacial polarization effect and the effective impedance match. The FeG composites prepared by gangue are promising candidates as light-weight and high-performance microwave absorbents in future applications. The novel method in this work may provide a new avenue for the resource utilization of gangue, turning waste into treasure, during which the economic and environmental benefit can be achieved.