Extraction chromatographic studies of uranium(VI) with crosslinked poly(acrylic acid) coated on silica gel

Abstract

A selective method has been developed for extraction and separation of U VI with the chemically synthesized high molecular mass crosslinked poly(acrylic acid) coated on silanized silica gel. The coated materials act as a stationary phase for the extraction chromatographic studies. The structure and thermal stability of crosslinked poly(acrylic acid) has been elucidated with the help of FTIR and TGA. The optimum pH range for quantitative extraction of uranium was found to be 4 to 6. The effects of pH and stripping agent on extraction and elution of U VI have been investigated. Ion exchange and break-through capacity of the exchanger (polymer coated on silanized silica gel) have been determined at room temperature. Surface morphology of the exchanger was studied by SEM. U VI has been separated quantitatively from various synthetic aqueous mixtures containing metal ions (V IV , Th IV , Ce IV , Pb II , Hg, In III , Fe III and Zr IV ) commonly present in uranium ores and fission products. The method permits pre-concentration and sequential separation of U VI from Ce VI , Th IV and Zr IV of the same analytical group. A plausible mechanism for uranium ion exchange has been suggested.