The Chemistry of Protactinium. III : A Study of the Sulfate Complex of Protactinium(V) by the Solvent Extraction Technique Using TTA as the Chelating Agent

Abstract

The behavior of pentavalent protactinium in sulfuric acid solutions was investigated by paper electrophoresis and by the TTA-benzene extraction method. From the results of this investigation, it is recognized that the Pa(OH)2(SO4)+ ion exists predominantly in dilute sulfuric acid solutions (pH 0.4–2.2), and that the complexing reaction of pentavalent protactinium by the sulfate ion may proceed as;Pa(OH)4++2H++SO42−\ightleftarrowsPa(OH)2(SO4)++2H2O.The stability constant of Pa(OH)2(SO4)+ was also determined by the solvent extraction method to be 6.4 at an ionic strength of 1.38.