The microwave absorption properties of residual carbon from coal gasification fine slag

• Published in: Fuel (Guildford) Vol. 290; p. 120050
• Main Authors: Gao, Shengtao, Zhang, Yuanchun, Li, Hanxu, He, Jun, Xu, Hang, Wu, Chengli
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 15.04.2021; Elsevier BV
• Subjects: Absorption; Acid leaching; Carbon; Coal; Coal gasification; Coal gasification fine slag; Dielectric loss; Graphitization; Graphitized carbon; Leaching; Microwave absorbers; Microwave absorption; Morphology; Paraffin; Paraffins; Properties (attributes); Residual carbon; Resource utilization; Slag; Stability analysis; Thermal stability; Residual carbon; Coal gasification fine slag; Microwave absorption; Graphitized carbon
• ISSN: 0016-2361; 1873-7153
• DOI: 10.1016/j.fuel.2020.120050

•The RC from gasification fine slag was obtained via an acid leaching process.•The RC has outstanding thermal stability and microwave-absorbing capability.•The RC is a competitively alternative and cheap source for microwave absorber.•The reasons of high microwave absorption are studied. The resource utilization of coal gasification fine slag (FS) is very urgent. The residual carbon (RC) from coal gasification FS was obtained via a facile two-step acid leaching process. The structure, compositions, micromorphology, thermal stability, and electromagnetic parameters of the RC were tested by variously analytical techniques in details. The RC exhibits the unique layer morphology and partial graphitization. Results demonstrate that the RC shows good thermal stability and microwave absorption (MA) properties. The outstanding microwave-absorbing capability may be caused by dielectric loss and polarization relaxation. Significantly, the RC content in the mixture has a noticeable impact on its MA properties. The minimum reflection loss of the RC achieved −52.3 dB at 5.04 GHz when the adding content was only 20% in a paraffin matrix. With an easy treating process, the RC obtained via an acid leaching method from coal gasification FS is a competitively alternative and cheap source for microwave absorber.