Improvements in or relating to the recovery of plutonium

摘要

865,699. Recovery of plutonium. UNITED KINGDOM ATOMIC ENERGY AUTHORITY. Feb. 1, 1960 [Feb. 13, 1959], No. 5191/59. Class 39(4). Plutonium is recovered from a slag comprising the fluoride of a highly electropositve metal by dissolving the slag in a solution containing nitric acid and aluminium ions and then extracting the plutonium with an organic' liquid comprising tributyl phosphate. The slag may arise in the reduction of plutonium tetrafluoride by magnesium, calcium, barium, lithium, sodium, or potassium. Preferably the dissolving solution contains at least 1.5 gramions of aluminium per litre and is at least 3 molar in nitric acid. After treatment at for example 90‹-95‹C., the undissolved residue may be further extracted with concentrated nitric acid at 95‹C. The organic liquid may be a 20% solution of tributyl phosphate in kerosene. The tributyl phosphate extract is washed with aqueous nitric acid and then contacted with an aqueous solution of hydroxylamine nitrate to reduce the plutonium and return it to the aqueous phase; alternatively the plutonium may be precipitated as oxalate as described in Specification 834,531.