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• Material Type: 文書・図像類
• Title: None
• Author/Editor: Takada; 広野 修一郎
• Author Heading: Takada; 広野 修一郎
• Publication Date: 1983-11
• Publication Date (W3CDTF): 1983-11
• Alternative Title: Development of uranium milling and conversion
• Periodical title: PNC TN441 83-03
• Text Language Code: eng
• Target Audience: 一般
• Note (General): The development and improvement of uranium milling and refining producing uranium tetrafluoride from ores by the wet process, without producing yellowcake as an intermediate product, have been carried out for over ten years with a small pilot plant (50 t-ore/day). In the past several years, a process for converting uranium tetrafluoride into hexafluoride has been developed successfully. To develop the process further, the construction of an integrated milling and conversion pilotplant (200 t-U/year) started in 1979 and was completed in 1981. This new plant has two systems of solvent extraction using tri-n-octylamine: one of the systems treats the pregnant solution (uranyl sulphate) by heap-leaching followed by ion exchange, and the other treats the uranyl sulphate solution by dissolving imported yellowcake. The uranium loading solvents from the two systems are stripped with hydrochloric acid solution to obtain the concentrated uranium solution containing 100 g-U/l. Uranyl sulphate solution from the stripping circuit is reduced to a uranous sulphate solution by the electrolytic method. In a reduction cell, uranyl sulphate solution and dilute sulphuric acid are used respectivery as catholyte and anolyte, and a cation exchange membrane is use to prevent re-oxidation of the uranous sulphate. In the following hydrofluorination step, uranium tetrafluoride, UF$_{4}$ 1-1, 2H$_{2}$O (particle soze: 50-100$\mu$), is produced continuously as the precipitate in an improved reaction vessele, and this makes it possible to simplify the procedures of liquid-solid separation, drying and granulation. The uranium tetrafkuoride is dehydrated by heating to 350$^{\circ}$C in an inert gas flow. The complete conversion from UF$_{4}$ is achieved by a fluidized-bereactor and a high value of utilization efficiency of fluorine, over 99.9 percent, is attained at about 400$^{\circ}$C.; None
• Source: /PNC-TN441-83-03.pdf （fulltext）; https://jopss.jaea.go.jp/pdfdata/PNC-TN441-83-03.pdf
• Access Restrictions: 限定公開
• Data Provider (Database): 国立情報学研究所 : 学術機関リポジトリデータベース（IRDB）（機関リポジトリ）; https://irdb.nii.ac.jp
• Original Data Provider (Database): 日本原子力研究開発機構 : JOPSS:JAEA Originated Papers Searching System

• Summary, etc.: The development and improvement of uranium milling and refining producing uranium tetrafluoride from ores by the wet process, without producing yellow...