Solvent extraction and separation of light lanthanoids with mixtures of two chelating extractants: Benzene vs. ionic liquid

ABSTRACT

Solvent extraction of lanthanoids (La-Gd) with mixtures of a chelating extractants (HL), either 4-(4-fluorobenzoyl)-3-methyl-1-phenyl-pyrazol-5-one(HPMFBP) or 3-methyl-4-(4-methylbenzoyl)-1-phenyl-pyrazol-5-one (HPMMBP) and 1-(2-thienyl)-4,4,4-trifluoro-1,3-butanedione (thenoyltrifluoroacetone, HTTA) has been studied in benzene. The composition of the extracted species was established as LnL₃·HL with the two para-substituted 4-aroyl-3-methyl-1-phenyl-pyrazol-5-ones. It was found that, in the presence of a thenoyltrifluoroacetone, the lanthanoids were extracted as LnL₃·HTTA. The separation factors between adjacent metals were evaluated. The extraction of Eu(III) ions was investigated by use of ionic liquid, 1-methyl-1,3-butylimidazolium-bis(trifluoromethanesulfonyl)imide instead of benzene in order to make comparison without looking at the mechanism aspects.

KEYWORDS:

• Solvent extraction
• lanthanoids
• 4-acyl-5-pyrazolones
• separation factors
• ionic liquid