Electroacoustic isoelectric point determinations of bauxite refinery residues: different neutralisation techniques and minor mineral effects

Simple item page
dc.contributor.authorFreire, TSSen_AU
dc.contributor.authorClark, MWen_AU
dc.contributor.authorComarmond, MJen_AU
dc.contributor.authorPayne, TEen_AU
dc.contributor.authorReichelt-Brushett, AJen_AU
dc.contributor.authorThorogood, GJen_AU
dc.date.accessioned2014-05-15T05:23:19Zen_AU
dc.date.available2014-05-15T05:23:19Zen_AU
dc.date.issued2012-08-14en_AU
dc.date.statistics2014-05-15en_AU
dc.description.abstract5Bauxite refinery residue (BRR) is a highly caustic, iron hydroxide-rich byproduct from alumina production. Some chemical treatments of BRR reduce soluble alkalinity and lower residue pH (to values <10) and generate a modified BRR (MBRR). MBRR has excellent acid neutralizing (ANC) and trace-metal adsorption capacities, making it particularly useful in environmental remediation. However, soluble ANC makes standard acid-base isoelectric point (IEP) determination difficult. Consequently, the IEP of a BRR and five MBRR derivatives (sulfuric acid-, carbon dioxide-, seawater-, a hybrid neutralization, i.e, partial CO2 neutralization followed by seawater, and an activated-seawater-neutralized MBRR) were determined using electroacoustic techniques. Residues showed three significantly different groups of IEPs (p < 0.05) based around the neutralization used. Where the primary mineral assemblage is effectively unchanged, the IEPs were not significantly different from BRR (pH 6.6-6.9), However, neutralizations generating neoformational minerals (alkalinity precipitation) significantly increased the IEP to pH 8.1, whereas activation (a removal of some primary mineralogy) significantly lowered the IEP to pH 6.2. Moreover, surface charging curves show that surfaces remain in the +/-30 mV surface charge instability range, which provides an explanation as to why MBRRs remove trace metals and oxyanions over a broad pH range, often simultaneously. Importantly, this work shows that minor mineral components in complex mineral systems may have a disproportionate effect on the observable bulk IEP. Furthermore, this work shows the appropriateness of electroacoustic techniques in investigating samples with significant soluble mineral components (e.g., ANC). © 2012, American Chemical Society.en_AU
dc.identifier.citationFreire, T. S. S., Clark, M. W., Comarmond, M. J., Payne, T. E., Reichelt-Brushett, A. J., & Thorogood, G. J. (2012). Electroacoustic isoelectric point determinations of bauxite refinery residues: different neutralisation techniques and minor mineral effects. Langmuir, 28(32), 11811-11820. doi:10.1021/la301790ven_AU
dc.identifier.govdoc4615en_AU
dc.identifier.issn0743-7463en_AU
dc.identifier.issue32en_AU
dc.identifier.journaltitleLangmuiren_AU
dc.identifier.pagination11802-11811en_AU
dc.identifier.urihttp://dx.doi.org/10.1021/la301790ven_AU
dc.identifier.urihttp://apo.ansto.gov.au/dspace/handle/10238/5578en_AU
dc.identifier.volume28en_AU
dc.language.isoenen_AU
dc.publisherAmerican Chemical Societyen_AU
dc.subjectWateren_AU
dc.subjectCapacityen_AU
dc.subjectBauxiteen_AU
dc.subjectResiduesen_AU
dc.subjectPhosphatesen_AU
dc.subjectAdsorptionen_AU
dc.titleElectroacoustic isoelectric point determinations of bauxite refinery residues: different neutralisation techniques and minor mineral effectsen_AU
dc.typeJournal Articleen_AU
Files
License bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
license.txt
Size:
1.71 KB
Format:
Item-specific license agreed upon to submission
Description:
Download
Collections
Journal Articles