Complexometric Determination of Sulfate

A simple and rapid method for the determination of sulfate in materials obtained during extraction of uranium from ores is based on precipitation as lead sulfate from acid solution containing isopropyl alcohol. The precipitate is filtered and redissolved in an excess of measured standard (ethylenedinitrilo)tetraacetic acid (EDTA) solution. The excess of the latter is then backtitrated with a standard zinc chioride solution and Eriochrome Black T as indicator. A detailed study of the optimum conditions for the precipitation of lead suifate has been carried out, and the degrees of interference of phosphate, arsenate, iron, and uranium ions have been tested. The method is virtually free of interferences and gives accurate results in the range 0.1 to 100% sulfates the time required for a determination is about 30 to 45 minutes. (auth)