dc.contributor.author |
Doucet, Frédéric J.
|
|
dc.contributor.author |
Mohamed, Sameera
|
|
dc.contributor.author |
Neyt, Nicole Candice
|
|
dc.contributor.author |
Castleman, Barbara A.
|
|
dc.contributor.author |
Van der Merwe, E.M. (Elizabet Margaretha)
|
|
dc.date.accessioned |
2016-12-06T06:56:12Z |
|
dc.date.issued |
2016-12 |
|
dc.description.abstract |
South African coal fly ash represents an untapped secondary resource of aluminium. Continuous research is conducted
to develop suitable chemical and/or geometallurgical processes for aluminium extraction, preferably accompanied
by minimal silicon extraction. The thermochemical treatment of a South African ultrafine coal fly ash
was investigated to test the feasibility of recovering aluminium using ammonium sulphate, a widely available,
low-cost, recyclable chemical agent. The optimum processing conditions were determined to be a temperature
of 500 °C and a fly ash to ammonium sulphate weight ratio of 2:6 when a reaction time of 1 h was used. Water
leaching of the reaction product obtained under these conditions resulted in the selective recovery of 95.0% aluminium
from the amorphous phase, with b0.6% Si extracted. Mullite was unlikely to have reacted with the
extracting agent. Except for Si, the process was not element-selective, but the extraction of iron could be minimized
by increasing the treatment temperature to 600 °C without compromising Al extraction. Thermochemical
treatment using ammonium sulphate may therefore represent a promising technology for extracting aluminium
from coal fly ash, which could be subsequently converted to value-added products such as alumina. |
en_ZA |
dc.description.department |
Chemistry |
en_ZA |
dc.description.embargo |
2017-12-31 |
|
dc.description.librarian |
hb2016 |
en_ZA |
dc.description.sponsorship |
The Council for Geoscience, the University of Pretoria and the National Research Foundation of South Africa (NRF; Grant No. 93641). |
en_ZA |
dc.description.uri |
http://www.elsevier.com/locate/hydromet |
en_ZA |
dc.identifier.citation |
Doucet, FJ, Mohamed, S, Neyt, N, Castleman, BA & Van der Merwe, EM 2016, 'Thermochemical processing of a South African ultrafine coal fly ash using ammonium sulphate as extracting agent for aluminium extraction', Hydrometallurgy, vol. 166, pp. 174-184. |
en_ZA |
dc.identifier.issn |
0304-386X (print) |
|
dc.identifier.issn |
1879-1158 (online) |
|
dc.identifier.other |
10.1016/j.hydromet.2016.07.017 |
|
dc.identifier.uri |
http://hdl.handle.net/2263/58360 |
|
dc.language.iso |
en |
en_ZA |
dc.publisher |
Elsevier Science Limited |
en_ZA |
dc.rights |
© 2016 Elsevier B.V. All rights reserved. Notice : this is the author’s version of a work that was accepted for publication in Hydrometallurgy. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. A definitive version was subsequently published in Hydrometallurgy, vol. 166, pp. 174-184., 2016. doi : 10.1016/j.hydromet.2016.07.017. |
en_ZA |
dc.subject |
Coal fly ash |
en_ZA |
dc.subject |
Thermochemical processing |
en_ZA |
dc.subject |
Aluminium extraction |
en_ZA |
dc.subject |
Ammonium sulphate |
en_ZA |
dc.title |
Thermochemical processing of a South African ultrafine coal fly ash using ammonium sulphate as extracting agent for aluminium extraction |
en_ZA |
dc.type |
Postprint Article |
en_ZA |