| 摘要 |
955, 394. Purifying radio-isotopes. COMMISSARIAT A L'ENERGIE ATOMIQUE. April 11, 1961 [April 15, 1960], No. 12955/61. Drawings to Specification. Heading G6R. Iodine-131 is produced by irradiating tellurium dioxide with neutrons, dissolving in an alkaline medium to form a solution containing more than 5% by weight of an alkali metal tellurite, oxidizing with hydrogen peroxide in the presence of an oxidation catalyst to convert the tellurite to a tellurate, acidifying the solution, and distilling off iodine-131. A process is described in which irradiated tellurium dioxide is dissolved in 5% sodium hydroxide with the addition of a little sodium iodate. Sodium molybdate as an oxidation catalyst is then introduced, followed by pure hydrogen peroxide in the presence of a stream of nitrogen. After completion of the oxidation, sulphuric acid is added to give a strength of 6N, together with a little sodium iodide. Iodine-131 is finally distilled off, being collected in a sodium bicarbonate-sodium carbonate-sodium thiosulphate solution. Other suitable oxidation catalysts are potassium molybdate and alkali metal vanadates. The whole process is carried out behind a protective shield; a suitable arrangement of apparatus is shown diagrammatically. |
