Microstructure and properties of mullite-based porous ceramics produced from coal fly ash with added Al2O3

• Published in: International journal of minerals, metallurgy and materials Vol. 24; no. 3; pp. 309 - 315
• Main Authors: Zhu, Jian-bin, Yan, Hong
• Format: Journal Article
• Language: English
• Published: Beijing University of Science and Technology Beijing 01.03.2017; Springer Nature B.V; School of Mechanical Electrical Engineering, Nanchang Institute of Technology, Nanchang 330000, China%Department of Materials Processing Engineering, School of Mechanical Electrical Engineering, Nanchang University, Nanchang 330000, China; Department of Materials Processing Engineering, School of Mechanical Electrical Engineering, Nanchang University, Nanchang 330000, China
• Subjects: Aluminum oxide; Ceramics; Characterization and Evaluation of Materials; Chemistry and Materials Science; Coal; Composites; Compressive strength; Corrosion and Coatings; Electrons; Fly ash; Glass; Industrial applications; Materials Science; Metallic Materials; Microstructure; Mullite; Natural Materials; Phase composition; Polymers; Silicon; Sintering (powder metallurgy); Slurries; Surfaces and Interfaces; Thin Films; Tribology; X-ray diffraction; mullite; ceramics; fly ash; aluminum oxide; porous materials
• ISSN: 1674-4799; 1869-103X
• DOI: 10.1007/s12613-017-1409-2

Using coal fly ash slurry samples supplemented with different amounts of Al2O3,we fabricated mullite-based porous ceramics via a dipping-polymer-replica approach,which is a popular method suitable for industrial application.The microstructure,phase composition,and compressive strength of the sintered samples were investigated.Mullite was identified in all of the prepared materials by X-ray diffraction analysis.The microstructure and compressive strength were strongly influenced by the content of Al2O3.As the Al/Si mole ratio in the starting materials was increased from 0.84 to 2.40,the amount of amorphous phases in the sintered microstructure decreased and the compressive strength of the sintered samples increased.A further increase in the Al2O3 content resulted in a decrease in the compressive strength of the sintered samples.The mullite-based porous ceramic with an Al/Si molar ratio of 2.40 exhibited the highest compressive strength and the greatest shrinkage among the investigated samples prepared using coal fly ash as the main starting material.