Publications

Abstract : To realize the effective recycling of solid waste fly ash (FA) and reduce the preparation cost of microwave absorbent, the Fe-loaded fly ash composites (FeFA) were synthesized using FA. In this study, the FeFA composites were prepared through granulation technology with FA, impregnation with Fe3+, and the carbothermal reduction process under different annealing temperatures, during which the Fe particles as main magnetic components were uniformly embedded into the interior and surface of the ceramic matrix. As expected, the FeFA800 composite showed superior microwave absorption (MA) performance, its minimum reflection loss (RLmin) value could reach −40.3 dB when the coating thickness was 2.5 mm and the effective bandwidth reached 4.1 GHz with the coating thickness of 1.5 mm. The attenuation of electromagnetic wave should benefit from the effective impedance matching characteristics and multiple interfacial polarization effects between the different components in the composite. Owing to the facile preparation process, excellent MA performance, and low cost, the FeFA composites with a density of 1.69–1.91 g/cm3 can be a promising candidate for application in the field of electromagnetic wave absorption and shielding. This work also opens up a way for the comprehensive recovery and utilization of FA.