Effects of Coal Gas Fine Ash on Electromagnetic Properties of Cement Mortar and Carbon Black Modification

Abstract

The present study explores the relationship between coal gas fine ash (CGFA) content and the electromagnetic performance of cement-based composites, and the modification effects of carbon black (CB), with particular focus on the electromagnetic property evolution in CB-CGFA systems at different formulation ratios. The experimental findings demonstrate that CGFA has a substantial impact on enhancing the electrical conductivity and complex permittivity of the composite material. The cement mortar demonstrates enhanced low-frequency (1–8 GHz) wave-absorbing characteristics. The numerical value of reflection loss (RL) exhibited a positive correlation with CGFA content, reaching an optimal value of −11.9 dB at 1.1 GHz for 2% CGFA content. The addition of CB to CGFA cement mortar facilitates to enhance its electromagnetic performance through synergistic effects within the cement matrix. This addition exhibits enhanced complex permittivity, characterised by combined polarization and resistive loss mechanisms. The absorbing performance exhibited a non-monotonic relationship with CB content, achieving an optimal RL of −18.95 dB at 4.24 GHz for 2% CGFA with 0.75% CB.

Keywords

coal gas fine ash / electromagnetic characteristic / electromagnetic wave absorption / cement mortar / electrical resistivity

References

[1] Jia W, Li L, Lei Y, et al.. Synergistic Effect of CO₂ and PM2.5 Emissions from Coal Consumption and the Impacts on Health Effects. Journal of Environmental Management, 2023, 325: 116 535. J].

[2] Guan Y, Shan Y, Huang Q, et al.. Assessment to China’s Recent Emission Pattern Shifts. Earth’s Future, 2021, 9(11): 1-13. J].

[3] Shi J, Wan N, Li L, et al.. Review on Treatment Technologies of Coal Gasification Wastewater in China. Journal of Cleaner Production, 2022, 333: 130 166. J].

[4] Xiao J, Wang S, Ye S, et al.. Thermo-Economic Optimization of Gasification Process With Coal Water Slurry Preheating Technology. Energy, 2020, 199: 117 354. J].

[5] Zheng S, Shi Y, Wang Z, et al.. Development of New Technology for Coal Gasification Purification and Research on the Formation Mechanism of Pollutants. International Journal of Coal Science & Technology, 2021, 8(3): 1-14. J].

[6] Liu W, Ouyang Z, Cao X, et al.. The Influence of Air-stage Method on Flameless Combustion of Coal Gasification Fly Ash with Coal Self-Preheating Technology. Fuel, 2019, 235: 1 368-1 376. J].

[7] Xie W, Zhang Z, Wang Y, et al.. Research on Grinding and Flotation Decarbonization of Coal Gasification Fine Slag. Fuel, 2024, 365: 131 136. J].

[8] Jiao Y, Yang Z, Han X, et al.. Ultrasonication Improves the Flotation of Coal Gasification Fine Slag Residue. Minerals, 2024, 14(4): 363. J].

[9] Mielke K, Wu G, Eberhard M, et al.. Optimization of Slag Mobility of Biomass Fuels in a Pilot-scale Entrained-Flow Gasifier. Chemical Engineering & Technology, 2021, 44(7): 1 302-1 310. J].

[10] Li J, Fan S, Zhang X, et al.. Investigation on Co-Combustion of Coal Gasification Fine Ash and Raw Coal Blends: Thermal Conversion, Gas Pollutant Emission and Kinetic Analyses. Energy, 2022, 246: 123 368. J].

[11] Jia W, Guo Y, Guo F, et al.. Co-Combustion of Carbon-Rich Fraction from Coal Gasification Fine Slag and Biochar: Gas Emission, Ash Sintering, Heavy Metals Evolutions and Environmental Risk Evaluation. Chemical Engineering Journal, 2023, 471: 144 312. J].

[12] Liu D, Wang W, Tu Y, et al.. Flotation Specificity of Coal Gasification Fine Slag Based on Release Analysis. Journal of Cleaner Production, 2022, 363: 132 426. J].

[13] Luo F, Jiang Y, Wei C. Potential of Decarbonized Coal Gasification Residues as the Mineral Admixture of Cement-Based Material. Construction and Building Materials, 2021, 269: 121 259. J].

[14] Li Z, Zhang Y, Zhao H, et al.. Structure Characteristics and Composition of Hydration Products of Coal Gasification Slag Mixed Cement and Lime. Construction and Building Materials, 2019, 213: 265-274. J].

[15] Luo F, Wei C. Effects of Decarbonized Coal Gasification Coarse Slag and Fine Ash on Properties of Cement Paste as Supplementary Cementitious Materials. Journal of Materials in Civil Engineering, 2022, 34(11): 04 022 281. J].

[16] Mao X, Zhao J, Liu J, et al.. Use of Coal Chemical Industry By-Product Coal Gasification Fine Ash as Supplementary Cementitious Materials in Cement: Chemical Excitation, Hydration and Hardening Characteristics. Construction and Building Materials, 2024, 426: 136 147. J].

[17] Xiang J, Qiu J, Zhao Y, et al.. Rheology, Mechanical Properties, and Hydration of Synergistically Activated Coal Gasification Slag with Three Typical Solid Wastes. Cement and Concrete Composites, 2024, 147: 105 418. J].

[18] Miao Z, Chen L, Chen K, et al.. Physical Properties and Microstructures of Residual Carbon and Slag Particles Present in Fine Slag from Entrained-Flow Coal Gasification. Advanced Powder Technology, 2020, 31(9): 3 781-3 789. J].

[19] Lü D-P, Bai Y-H, Wang J-F, et al.. Structural Features and Combustion Reactivity of Residual Carbon in Fine Slag from Entrained-Flow Gas-ification. Journal of Fuel Chemistry and Technology, 2021, 49(2): 129-136. J].

[20] Wang Q, Bai Y, Lv P, et al.. Separation and Characterization of Different Types of Residual Carbon in Fine Slag from Entrained Flow Coal Gasification. Fuel, 2023, 339: 127 437. J].

[21] Dai G, Zheng S, Wang X, et al.. Combustibility Analysis of High-Carbon Fine Slags from an Entrained Flow Gasifier. Journal of Environmental Management, 2020, 271: 111 009. J].

[22] Xu S, Zhou Z, Gao X, et al.. The Gasification Reactivity of Unburned Carbon Present in Gasification Slag from Entrained-Flow Gasifier. Fuel Processing Technology, 2009, 90(9): 1 062-1 070. J].

[23] Guo F, Chen L, Li Y, et al.. Review on the Attribute Cognition and Carbon-Ash-Water Separation of Coal Gasification Fine Slag. Separation and Purification Technology, 2023, 320: 124 121. J].

[24] Gao S, Chen L, Zhang Y, et al.. FeO_x Nanoparticle/Coal Gasification Fine Slag Hybrids for Electromagnetic Wave Absorbers. ACS Applied Nano Materials, 2022, 5: 7 767-7 677. J].

[25] He J, Gao S, Zhang Y, et al.. Nanoferric Tetroxide Decorated N-Doped Residual Carbon from Entrained-Flow Coal Gasification Fine Slag for Enhancing the Electromagnetic Wave Absorption Capacity. Journal of Alloys and Compounds, 2021, 874: 159 878. J].

[26] Gao S, Zhang Y, Li H, et al.. The Microwave Absorption Properties of Residual Carbon from Coal Gasification Fine Slag. Fuel, 2021, 290: 120 050. J].

[27] Csga B, Al C, Cy Z, et al.. Fe Nanoparticles Decorated in Residual Carbon from Coal Gasification Fine Slag as an Ultra-Thin Wideband Microwave Absorber. Composites Science and Technology, 2021, 213: 108 921. J].

[28] Zhang X, Zhang Y, He J, et al.. ZnFe₂O₄ Nanospheres Decorated Residual Carbon from Coal Gasification Fine Slag as an Ultra-Thin Microwave Absorber. Fuel, 2023, 331: 125 811. J].

[29] Zhang Y, Gao S, Zhang X, et al.. Structural and Microwave Absorption Properties of CoFe₂O₄/residual Carbon Composites. International Journal of Minerals, Metallurgy and Materials, 2024, 32(1): 221-232. J].

[30] Gao ST, Z Y. Physicochemical Properties and Electromagnetic Wave Absorption Performance of Coal Gasification Fine Ash. Acta Materiae Compositae Sinica, 2024, 41: 2 559-2 574. [J].

[31] Xie S, Wang J, Wang W, et al.. Electromagnetic Wave Absorption Properties of Cement Based Composites Using Helical Carbon Fibers as Absorbent. Materials Research Express, 2018, 5(2): 025 605. J].

[32] Park G, Kim S, Park G-K, et al.. Influence of Carbon Fiber on the Electromagnetic Shielding Effectiveness of High-Performance Fiber-Reinforced Cementitious Composites. Journal of Building Engineering, 2021, 35: 101 982. J].

[33] Zhang L, Han B, Ouyang J, et al.. Multifunctionality of Cement Based Composite with Electrostatic Self-Assembled CNT/NCB Composite Filler. Archives of Civil and Mechanical Engineering, 2017, 17(2): 354-364. J].

[34] Zhang W, Zheng Q, Wang D, et al.. Electromagnetic Properties and Mechanisms of Multiwalled Carbon Nanotubes Modified Cementi-tious Composites. Construction and Building Materials, 2019, 208: 427-443. J].

[35] Sachdev VK, Sharma SK, Bhattacharya S, et al.. Electromagnetic Shielding Performance of Graphite in Cement Matrix for Applied Applicatio. Advanced Materials Letters, 2015, 6(11): 965-972. J].

[36] Bhattacharya S, Sachdev VK, Chatterjee R, et al.. Decisive Properties of Graphite-Filled Cement Composites for Device Application. Applied Physics A, 2008, 92(2): 417-420. J].

[37] Li B, Ji Z, Xie S, et al.. Electromagnetic Wave Absorption Properties of Carbon Black/Cement-Based Composites Filled with Porous Glass Pellets. Journal of Materials Science: Materials in Electronics, 2019, 30(13): 12 416-12 425. [J].

[38] Wu J, Xie S, Ji Z, et al.. Effect of Carbon Black Dispersion on Cement Mortar Properties: Microstructure and Electromagnetic Properties. Mechanics of Advanced Materials and Structures, 2025, 32(17): 4 244-4 259. J].

[39] Wu J, Xie S, Ji Z, et al. Effect of Nano Carbon Black Content and Dispersibility on the Properties of Cement Paste[J]. Proceedings of the Institution of Civil Engineers - Transport, 2024: 1–13

[40] Lee N, Kim S, Park G. The Effects of Multi-Walled Carbon Nanotubes and Steel Fibers on the AC Impedance and Electromagnetic Shielding Effectiveness of High-Performance, Fiber-Reinforced Cementitious Composites. Materials, 2019, 12(21): 3 591-3 591. J].

[41] Papachristoforou M, Papayianni I. Radiation Shielding and Mechanical Properties of Steel Fiber Reinforced Concrete (SFRC) Produced with EAF Slag Aggregates. Radiation Physics and Chemistry, 2018, 149: 26-32. J].

[42] Ma C, Xie S, Ji Z, et al.. Electromagnetic Wave Absorbing Properties of Pyramidal Engineered Cement Mortar Containing Carbon Black. Journal of Building Engineering, 2024, 84: 108618. J].

[43] Wu Z, Xie S, Ji Z, et al.. Novel Lightweight Cement-Based Materials Foaming by Secondary Aluminum Ash: Microwave Absorption, Mechanical and Thermal Insulation Properties. Construction and Building Materials, 2024, 413: 134 328. J].

[44] Qin H, Liao Q, Zhang G, et al.. Microwave Absorption Properties of Carbon Black and Tetrapod-Like Zno Whiskers Composites. Applied Surface Science, 2013, 286: 7-11. J].

[45] Yue L, Yang Y, Zhou Q, et al.. Broadband Electromagnetic Wave Absorbing Performance by Designing the Foam Structure and Double-Layer for Cement-Based Composites Containing MWCNTs. Cement and Concrete Composites, 2022, 131: 104 595. J].

[46] Tan L, Zhu M, Li X, et al.. Lightweight Excellent Microwave Absorption Properties Based on Sulfur Doped Graphene. Journal of Saudi Chemical Society, 2020, 24(1): 9-19. J].

[47] Xing W, Li P, Wang H, et al.. The Similar Cole-Cole Semicircles and Microwave Absorption of Hexagonal Co/C Composites. Journal of Alloys and Compounds, 2018, 750: 917-926. J].

[48] Li D, Liang X, Liu W, et al.. Adjustable 3-D Structure with Enhanced Interfaces and Junctions Towards Microwave Response Using FeCo/C Core-Shell Nanocomposites. Journal of Colloid and Interface Science, 2017, 507: 131-138. J].

[49] Deng G, Yang Y, Zhou Q, et al.. Lightweight and Broadband Electromagnetic Wave Absorbing Foamed Cement-Based Composites Incorporated with Hybrid Dielectric Fibers. Construction and Building Materials, 2022, 327: 126 931. J].

[50] Si T, Xie S, Ma C, et al.. Microwave Absorption Properties of Double-Layer Structured Basalt Fiber/Resin Composites Containing Carbon Black and Nano-Fe₃O₄. Composite Interfaces, 2023, 30(9): 959-981. J].

[51] Dai Y, Sun M, Liu C, et al.. Electromagnetic Wave Absorbing Characteristics of Carbon Black Cement-Based Composites. Cement and Concrete Composites, 2010, 32(7): 508-513. J].

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