THE USE OF CARBONATE LIXIVIANTS TO REMOVE URANIUM FROM URANIUM-CONTAMINATED SOILS

The objective of this research was to design an extraction media and p rocedure that would selectively remove uranium without adversely affec ting the soils' physicochemical characteristics or generating secondar y waste forms difficult to manage or dispose of. Investigations center ed around determining the best lixiviant and how the various factors s uch as pH, time, and temperature influenced extraction efficiency. Oth er factors investigated included the influence of attrition scrubbing, the effect of oxidants and reductants, and the recycling of lixiviant s. Experimental data obtained at the bench-and pilot-scale levels indi cated 80% to 95% of the uranium could be removed from the uranium-cont aminated soils by using a carbonate lixiviant. The best treatment was three successive extractions with 0.25M carbonate-bicarbonate (in pres ence of KMnO4 as an oxidant) at 40 degrees C followed with two water r inses.