Solvent Extraction of Alkaline Earth Metals with Alkylphosphorus Acids

Abstract

Abstract: Solvent extraction equilibria of four main alkaline earth metals (magnesium, calcium,
strontium and barium) with di(2-ethylhexyl) phosphoric acid (DEHPA), 2-ethylhexyl
phosphonic acid mono-(2-ethylhexyl) ester,di(2,4,4-tri-methylpentyl) phosphinic acid and IR
spectra of the extracts have been studied. The selectivity order is dependent on the e/r
value and hydration energy of the metal ions. The minor shift of the P-O in IR absorption
of the alkaline earth metal extracts indicates that the interaction between the metal ions
and P-O is much weaker for alkaline earth metals than for transitional metals. The
distribution of the four alkaline earth elements between aqueous solutions and solutions of
DEHPA and neutral organophosphorus compounds, tri-n-butyl phosphate (TBP) or tri-octyl
phosphine oxide (TOPO) in kerosene have been determined at varying ratio of TBP or TOPO to
DEHPA and the positive synergism is observed. The synergic effect is explained by using IR
spectra of the loaded organic phase.

Key words: solvent extraction, alkaline earth metals, di(2-ethylhexyl) phosphoric acid (DEHPA)

摘要： Solvent extraction equilibria of four main alkaline earth metals (magnesium, calcium,
strontium and barium) with di(2-ethylhexyl) phosphoric acid (DEHPA), 2-ethylhexyl
phosphonic acid mono-(2-ethylhexyl) ester,di(2,4,4-tri-methylpentyl) phosphinic acid and IR
spectra of the extracts have been studied. The selectivity order is dependent on the e/r
value and hydration energy of the metal ions. The minor shift of the P-O in IR absorption
of the alkaline earth metal extracts indicates that the interaction between the metal ions
and P-O is much weaker for alkaline earth metals than for transitional metals. The
distribution of the four alkaline earth elements between aqueous solutions and solutions of
DEHPA and neutral organophosphorus compounds, tri-n-butyl phosphate (TBP) or tri-octyl
phosphine oxide (TOPO) in kerosene have been determined at varying ratio of TBP or TOPO to
DEHPA and the positive synergism is observed. The synergic effect is explained by using IR
spectra of the loaded organic phase.

关键词: solvent extraction;alkaline earth metals;di(2-ethylhexyl) phosphoric acid (DEHPA)

XU Xin, ZHU Tun. Solvent Extraction of Alkaline Earth Metals with Alkylphosphorus Acids[J]. .

许新, 朱屯. 有机磷(膦)酸对碱土金属的萃取[J]. CIESC Journal.

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