| 摘要 |
<p>859,191. Separation of plutonium. UNITED KINGDOM ATOMIC ENERGY AUTHORITY. Aug. 28, 1945 [Sept. 2, 1944], No. 22177/45. Drawings to Specification. Class 39(4). Plutonium is separated from solution by precipitating a metal hydroxide which carries down the plutonium, redissolving the precipitate, and repeating the process with another metal hydroxide. A solution of neutron-irradiated uranium is treated to remove uranium and fission products by the bismuth phosphate precipitation method as described in U.S.A. Specification 2,785,951 and the concentrated plutonium fraction in acid solution is contacted with a hydroxide of aluminium, bismuth, copper, chromium, cobalt, iron, lanthanum, nickel, or zirconium by adding a soluble salt of the metal followed by hydroxide iron, e.g. as sodium hydroxide, and stirring at 75‹C. for 1¢-2 hours. The precipitate is removed and redissolved and another carrier metal hydroxide formed in a similar manner. Before precipitating the hydroxides, sodium or potassium ferrocyanide may be added to remove iron present by precipitation ; or oxyalic or citric acid may be added to prevent precipitation of iron and bismuth hydroxides. In examples, a precipitate of aluminium hydroxide is first formed, this is dissolved in sodium hydroxide, and then a precipitate of copper hydroxide is formed which is removed and dissolved in ammonium hydroxide. Further metal hydroxide precipitations or a lanthanum fluoride precipitation may follow. Reference is made to reversing the order of the aluminium and copper hydroxide precipitations and to using hydroxides of chromium, nickel, or cobalt in place of copper hydroxide. The Specification as open to inspection under Section 91 comprises also processes, in which there is only one hydroxide precipitation ; an additional example describes the use of hydroxides of zirconium, lanthanum, aluminium and copper. This subject-matter does not appear in the Specication as accepted. Specification 853,311 also is referred to.</p> |
