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Phase transformations of α-alumina made from waste aluminum via a precipitation technique


Matori, Khamirul Amin and Loy, Chee Wah and Hashim, Mansor and Ismail, Ismayadi and Mohd Zaid, Mohd Hafiz (2012) Phase transformations of α-alumina made from waste aluminum via a precipitation technique. International Journal of Molecular Sciences, 13 (12). pp. 16812-16821. ISSN 1661-6596; ESSN: 1422-0067


We report on a recycling project in which α-Al2O3 was produced from aluminum cans because no such work has been reported in literature. Heated aluminum cans were mixed with 8.0 M of H2SO4 solution to form an Al2(SO4)3 solution. The Al2(SO4)3 salt was contained in a white semi-liquid solution with excess H2SO4; some unreacted aluminum pieces were also present. The solution was filtered and mixed with ethanol in a ratio of 2:3, to form a white solid of Al2(SO4)3·18H2O. The Al2(SO4)3·18H2O was calcined in an electrical furnace for 3 h at temperatures of 400–1400 °C. The heating and cooling rates were 10 °C /min. XRD was used to investigate the phase changes at different temperatures and XRF was used to determine the elemental composition in the alumina produced. A series of different alumina compositions, made by repeated dehydration and desulfonation of the Al2(SO4)3·18H2O, is reported. All transitional alumina phases produced at low temperatures were converted to α-Al2O3 at high temperatures. The X-ray diffraction results indicated that the α-Al2O3 phase was realized when the calcination temperature was at 1200 °C or higher.

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Official URL or Download Paper: https://www.mdpi.com/1422-0067/13/12/16812

Additional Metadata

Item Type: Article
Divisions: Faculty of Science
Institute of Advanced Technology
DOI Number: https://doi.org/10.3390/ijms131216812
Publisher: MDPI
Keywords: Precipitation; Calcinations; Phase transformations; α-alumina
Depositing User: Nabilah Mustapa
Date Deposited: 02 Jun 2020 03:07
Last Modified: 02 Jun 2020 03:07
Altmetrics: http://www.altmetric.com/details.php?domain=psasir.upm.edu.my&doi=10.3390/ijms131216812
URI: http://psasir.upm.edu.my/id/eprint/78035
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