Separation of uranium and thorium on ammonium phosphotungstate in nitric acid

Exchange behaviour of uranium and thorium on ammonium phosphotungstate (APW) was investigated in nitric acid medium. Distribution coefficients were determined and exchange isotherms and break-through profiles of thorium were studied. Suitable eluting agents were tested for the regeneration of the exchanger-bed. The exchanger was found to exhibit favourable behaviour for the separation of thorium and uranium in nitric acid medium. The results were tested by a series of column separations and the optimum feed compositions were suggested to yield the best results. Finally, a separation scheme was worked out for the separation and purification of U233 from its thorium contamination in the tail-end uranium solution from the thorex reprocessing plant. (author)