Abstract

DUPERLY YARURO, Gladis; LAVERDE, Dionisio Antonio  and  ESCALANTE, Humberto. Liquid-liquid extraction of barium with DEPHA: chemical equilibrium. Rev.fac.ing.univ. Antioquia [online]. 2006, n.36, pp.110-120. ISSN 0120-6230.

The objective of this work was to evaluate a liquid - liquid extraction process to separate barium in aqueous phase by means of an organic phase consisting of DEPHA (bis-2-ethylhexyl phosphate) in kerosene and isopropyl alcohol as modifying agent. Different variables were studied: a) metal concentration in the liquid phase, b) pH of the solution, c) concentration of the organic carrier and d) ratio of the organic to aqueous phase volume. A recovery efficiency of 89.5% was obtained using an organic solution based on DEPHA, 30% (V/V) and isopropyl alcohol, 30% (V/V) as selective extraction medium. The extraction of barium occurs at pH 11. A solution containing 100 mg/L of BaCl₂.2H₂O was used as aqueous phase. The chemical equilibrium present in the system was described and the parameter Kq_E = 0.338 was obtained. This parameter is useful for establishing the viability of the industrial barium separation process in the aqueous phase.

Keywords : barium; heavy metals; liquid-liquid extraction; DEPHA.

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