Polarographic determination of uranium in monazite sands

Abstract

A practical method is described for the extraction of uranium from monazite sands and its subsequent polarographic determination.

The sample is decomposed by fusion with potassium hydrogen difluoride followed by fusion with potassium pyrosulphate. Uranium is extracted from nitric acid solution with tributyl phosphate in 2,2,4-trimethylpentane, with aluminium nitrate as a salting-out agent, and back-extracted from the organic phase with water.

The final polarographic determination is carried out in 2 M acetic acid-2 M ammonium acetate-0·1 M ascorbic acid solution as supporting electrolyte. Neither a maximum suppressor nor removal of oxygen is needed.

The interference by lead and some factors influencing the extraction of uranium are studied.

The results are reproducible and agree with those obtained by other, more laborious, techniques. The proposed procedure is suitable for the determination of uranium in monazites and monazite sand concentrates containing not less than 0·005 per cent. of uranium oxide, and is superior in speed, reliability and convenience to other methods previously reported.