Cracking behavior and mechanism of gibbsite crystallites during calcination

Zhang, Jinxuan and Ge, Lei and Chen, Zhi-Gang and Boom, Eric and Zhu, Zhonghua (2019) Cracking behavior and mechanism of gibbsite crystallites during calcination. Crystal Research and Technology, 54 (1 - Article 1800201). ISSN 0232-1300

Abstract

Cracking is one of the major contributors to the breakage of gibbsite particles during calcination, which generates superfine particles causing detrimental effects to the quality of product in the downstream smelter grade alumina production. Therefore, understanding the cracking behavior and mechanism can provide a solution to avoid the generation of superfine particles. In this study, for the first time, the phase transformation and structural evolutions from gibbsite to boehmite then to amorphous alumina during calcination via using focus ion beam–scanning electronic microscopy and in situ transmission electron microscopy are investigated. After detailed and real‐time observations, it is illustrated that the crack formation on gibbsite particles during calcination can be attributed to the stress introduced by crystal shrinkage inside the crystallites during the phase transformation. Moreover, cracks in calcined gibbsite crystallites are found to initiate as pores inside the crystallites, which grow toward the surface and then form open cracks. Studies will open the possibility to tune the breakage of gibbsite particles.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: Permanent restricted access to Published version, in accordance with the copyright policy of the publisher.
Faculty/School / Institute/Centre: Current - Institute for Advanced Engineering and Space Sciences - Centre for Future Materials
Date Deposited: 26 Feb 2019 03:14
Last Modified: 12 Mar 2019 04:51
Uncontrolled Keywords: calcination, cracking behavior, cracking mechanism, gibbsite crystallite
Fields of Research : 09 Engineering > 0912 Materials Engineering > 091205 Functional Materials
Funding Details:
Identification Number or DOI: 10.1002/crat.201800201
URI: http://eprints.usq.edu.au/id/eprint/36057

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