2016-Sustainable Industrial Processing Summit
SIPS 2016 Volume 11: Physics, Advanced/Multifunctional Materials, Composite, Quasi-crystals, Coating
| Editors: | Kongoli F, Marquis F, Lu L, Xia H, Masset P, Rokicki P |
| Publisher: | Flogen Star OUTREACH |
| Publication Year: | 2016 |
| Pages: | 180 pages |
| ISBN: | 978-1-987820-56-0 |
| ISSN: | 2291-1227 (Metals and Materials Processing in a Clean Environment Series) |
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Phase Compositions and Microstructure of Alumina/Calcium-Hexaluminate composites
Yingyi Zhang1;1, Chongqing, China;
Type of Paper: Regular
Id Paper: 17
Topic: 8
Abstract:
Alumina/calcium-hexaluminate composites was synthesized through reaction sintering of alumina and bauxite reducing slag. The alumina/calcium-hexaluminate composites is mainly composed of 6.57% 再-Al2O3, 23.92% anorthite, and 57.13% calcium-hexaluminate. Gehlenite phase was effectively transformed to anorthite and calcium-hexaluminate through high-temperature reaction sintering under a weak oxidizing atmosphere at 1400 ｛C for 4 h. SEM and EDS analysis indicated that black and needle-shaped Al2O3, rhombic or irregular polygonal-shaped hercynite and glassy-phase gehlenite disappeared after the reaction sintering. The light gray and flaky hexagon crystals of calcium-hexaluminate (10 匈m) and the grainy particles of Al2O3 (2每7 匈m) were also observed in the alumina/calcium-hexaluminate composites. The gray crystals of anorthite act as binding phase and are distributed around calcium-hexaluminate and Al2O3. Alumina/calcium-hexaluminate composites present high refractoriness and using temperature, which are 1650 ｛C and 1450 ｛C, respectively. Reaction sintering between alumina and bauxite reducing slag is a feasible method for the synthesis of alumina/calcium-hexaluminate composites.
Keywords: Bauxite, Alumina, Calcium hexaluminate, Phase compositions, Microstructure