Original scientific paper

Extraction and Separation of Tantalum(V) with 3-Hydroxy-2-methyl-1-(4-tolyl)-4-pyridone

Vlasta Vojković ; Laboratory of Analytical Chemistry, Faculty of Science, University of Zagreb, Strossmayerov trg 14, 10000 Zagreb, Croatia
Astrid Gojmerac lvšić ; Laboratory of Analytical Chemistry, Faculty of Science, University of Zagreb, Strossmayerov trg 14, 10000 Zagreb, Croatia
Biserka Tamhina ; Laboratory of Analytical Chemistry, Faculty of Science, University of Zagreb, Strossmayerov trg 14, 10000 Zagreb, Croatia

Abstract

Extraction of tantalum(V) from aqueous oxalic solution with 3 hydroxy- 2-methyl-1-(4-tolyl)-4-pyridone (HY) dissolved in chloroform
has been examined at different acidities and ionic strengths. Tantalum( V) is quantitatively extracted with HY from oxalic solution
at pH = 2.3-2.5, probably as a mixed ligand Ta-oxalate-HY complex.
Tantalum(V) can be quantitatively extracted even from a more acidic solution in the presence of sulphuric, hydrochloric or perchloric acids, in the acidity range from pH = 2.3 to 3.5 M H2S04 or HCI and from pH = 2.3 to 5.5 M HCI04. Thiocyanate, perchlorate and chloride ions produce a synergistic effect on the tantalum(V) extraction with HY. In the presence of an excess of thiocyanate, perchlorate or chloride ions, tantalumtV) is quantitatively extracted with HY in the acidity range from pH = 2.3 to 3.5 M H2S04 as a mixed ligand Ta-NCS-HY, Ta-CI04-HY or in the form of Ta-CI-HY complexes. Compositions of the complexes are studied and discussed. Tantalum(V) extraction with HY enables its separation from niobium(V), zirconium(IV) and hafnium(IV).

Keywords

Hrčak ID:

176965

URI

https://hrcak.srce.hr/176965

Publication date:

1.5.1997.

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