Investigation of the separation of scandium and rare earth elements from red mud by use of reversed-phase HPLC

Tsakanika, LV; Ochsenkuhn-Petropoulou, MTh; Mendrinos, LN

dc.contributor.author	Tsakanika, LV	en
dc.contributor.author	Ochsenkuhn-Petropoulou, MTh	en
dc.contributor.author	Mendrinos, LN	en
dc.date.accessioned	2014-03-01T01:20:40Z
dc.date.available	2014-03-01T01:20:40Z
dc.date.issued	2004	en
dc.identifier.issn	1618-2642	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/16008
dc.subject	Rare earth elements	en
dc.subject	Red mud	en
dc.subject	Scandium	en
dc.subject	Separation by reversed-phase high-performance liquid chromatography	en
dc.subject.classification	Biochemical Research Methods	en
dc.subject.classification	Chemistry, Analytical	en
dc.subject.other	Filtration	en
dc.subject.other	High performance liquid chromatography	en
dc.subject.other	Hydrophobicity	en
dc.subject.other	Ion exchange	en
dc.subject.other	Leaching	en
dc.subject.other	Negative ions	en
dc.subject.other	Phase separation	en
dc.subject.other	Rare earth elements	en
dc.subject.other	Hydrometallurgical treatments	en
dc.subject.other	Red mud (RM)	en
dc.subject.other	Separation by reversed-phase high-performance liquid chromatography	en
dc.subject.other	Supermagnetics	en
dc.subject.other	Scandium	en
dc.title	Investigation of the separation of scandium and rare earth elements from red mud by use of reversed-phase HPLC	en
heal.type	journalArticle	en
heal.identifier.primary	10.1007/s00216-004-2667-1	en
heal.identifier.secondary	http://dx.doi.org/10.1007/s00216-004-2667-1	en
heal.language	English	en
heal.publicationDate	2004	en
heal.abstract	A chromatographic method has been developed for separation and determination of scandium (Sc) and rare earth elements (REEs) in samples from a red mud (RM)-utilization process. Reversed-phase high-performance liquid chromatography (RP-HPLC) with post-column derivatization using 4-(2-pyridylazo)-resorcinol (PAR) and UV-visible detection at 520 nm was tested using different gradient elution profiles and pH values to optimize separation and recovery, primarily for Sc but also for yttrium and the individual lanthanides, from iron present in the samples. The separation was performed in less than 20 min by use of a mobile phase gradient. The concentration of α-hydroxyisobutyric acid (α-HIBA), as eluent, was altered from 0.06 to 0.4 mol L-1 (pH 3.7) and 0.01 mol L-1 sodium salt n-octane sulfonic acid (OS) was used as modifier. Very low detection limits in the nanogram range and a good resolution for Sc and REEs except for Y/Dy were achieved. Before application of the method to the red mud samples and to the corresponding bauxites, Sc and REEs were leached from red mud with 0.6 mol L-1 HNO3 and mostly separated, as a group, from the main elements by ion exchange/selective elution (6 mol L-1 HNO 3) in accordance with a pilot-plant process developed in this laboratory. After evaporation of the eluent to dryness the extracted elements were re-dissolved in the mobile phase. By use of this chromatographic method Sc, which is the most expensive of the elements investigated and occurs in economically interesting concentrations in red mud, could be separated not only from co-existing Fe but also from Y/Dy, Yb, Er, Ho, Gd, Eu, Sm, Nd, Pr, Ce and La. All the elements investigated were individually recovered. Their recoveries were found to be nearly quantitative. © Springer-Verlag 2004.	en
heal.publisher	SPRINGER HEIDELBERG	en
heal.journalName	Analytical and Bioanalytical Chemistry	en
dc.identifier.doi	10.1007/s00216-004-2667-1	en
dc.identifier.isi	ISI:000223474200011	en
dc.identifier.volume	379	en
dc.identifier.issue	5-6	en
dc.identifier.spage	796	en
dc.identifier.epage	802	en