Mixer uranium purification

It is envisaged that this process could be operated with the simple type of mechanically stirred mixer-settler which is satisfactory in the Springfields uranium purification process. The Femald type of sieve-plate pulse column is another alternative. 

The simple box-type mixer—settler (113) has been used extensively in the UK for the separation and purification of uranium and plutonium (114). In this type of extractor, interstage flow is handled through a partitioned box constmction. Interstage pumping is not needed because the driving force is provided by the density difference between solutions in successive stages (see Plutoniumand plutonium compounds Uraniumand uranium compounds). 

The Purex process is presented schematically in Figure 21.11, where the solvit extraction steps are within the dotted frame. Three purification cycles for both uranium and plutonium are shown. High levels of beta and gamma activity is presort only in the first cycle, in which > 99 % of the fission products are separated. The principle of the first cycle is shown in Fig. 21.13. The two other cycles are based upon the same chemical reactions as in the first cycle the purpose is to obtain additional decontamination and overall purity of the uranium and plutonium products. Each square in Figure 21.13 indicates a number of solvent extraction stages of the particular equipment used pulsed columns, mixer-settlers, etc. (see Appoidix A). 

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