Please use this identifier to cite or link to this item: http://hdl.handle.net/1822/46665

TitleRed mud-based geopolymers with tailored alkali diffusion properties and pH buffering ability
Author(s)Ascensão, G.
Seabra, M. P.
Aguiar, J. L. Barroso de
Labrincha, J. A.
KeywordsAlkali leaching
Geopolymer
pH buffering
Red mud
Issue dateMar-2017
PublisherElsevier Science
JournalJournal of Cleaner Production
CitationAscensão G., Seabra M. P., Aguiar J. B., Labrincha J. A. Red mud-based geopolymers with tailored alkali diffusion properties and pH buffering ability, Journal of Cleaner Production, Vol. 148, pp. 23-30, doi:10.1016/j.jclepro.2017.01.150, 2017
Abstract(s)This study develop novel porous red mud (RM) based geopolymers and evaluates their potential to ensure prolonged pH control. Several properties of the novel geopolymers were examined including buffering ability, alkalis leaching behaviour, mineralogical composition, microstructure and physical properties. Two experimental plans were defined to evaluate the influence of porosity and RM content on those properties. The pH values of the eluted water and geopolymers OH ions leaching have been determined over time showing that total OH ions and the leaching rate can be tailored by controlling the geopolymers porous structure and the availability of free alkaline species. The lower pH gradient over 28th d (1.64 pH units) was achieved by combining a 0.025 wt% pore forming agent (aluminium powder) with 45 wt% MK replacement by red mud. A high and prolonged buffer capacity was accomplished, proving that red mud-based geopolymers have potential to be applied as pH buffering material.
TypeArticle
URIhttp://hdl.handle.net/1822/46665
DOI10.1016/j.jclepro.2017.01.150
ISSN0959-6526
Publisher versionhttps://doi.org/10.1016/j.jclepro.2017.01.150
Peer-Reviewedyes
AccessOpen access
Appears in Collections:C-TAC - Artigos em Revistas Internacionais

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