Removal of radioactivity from lanthanum oxide: Pt.3

Bench Scale experiments for the separation of lanthanum and actinium in nitric acid medium are carried out with multistage annular centrifugal extractors in series. The results indicate that HEHEHP is an excellent extractant for this purpose and that pH value, phase ratio, and stage number of the scrubbing section are the main factors which influence the separation of lanthanum from actinium. Process parameters are verified. At proper conditions the recovery of lanthanum is 91-99%, decontamination factor is 300-1900 for α-radioactivity, 300-600 for calcium with calcium content lower than 50 ppm in the product. Valuable information is obtained for the industrial scale purification of La2O3