Phase and Microstructure Evolution of Mullite Synthesized from Coal Gangue and γ-Al₂O₃

Abstract:

Mullite with puncheon-like grains was synthesized by sintering the mixtures of coal gangue and γ-Al₂O₃ at 1400 °C~1550 °C for 4 h. The phase and microstructure evolution of the mullitization behavior were investigated by XRD, SEM and EDS. Phases of the sintered specimens were mullite, corundum and cristobalite at 1400 °C to 1450 °C. Arise of temperature would enhance mullitization, and total consumption of cristobalite occurred from 1500 °C upward. The in-situ produced primary mullite from gangue upon heating may be seeds for the growth of enenly dispersed mullite puncheons. Specimen sintered at 1550 °C consists of puncheons with an aspect ratio of 2~4, regionally forming an interlocking structure.

• Periodical: Advanced Materials Research (Volume 624)
• Pages: 17-21
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.624.17
• Online since: December 2012
• Authors: Hai Peng Ji, Zhao Hui Huang, Kai Chen, Ming Hao Fang, Jun Tong Huang, Yan Gai Liu
• Keywords: Coal Gangue, Mullite, Puncheon Grain

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