Patents by Inventor Hiroshi Ishimi

Hiroshi Ishimi has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 4374807
    Abstract: In a process for converting UF.sub.6 into UO.sub.2, the UF.sub.6 is brought into contact with an aqueous aluminum nitrate solution. The resultant product is solvent extracted with tributyl phosphate to remove uranyl nitrate. The raffinate has a fluorine/aluminum (F/Al) weight ratio within the range of from about 0.5 to about 1.2. A sufficient quantity of hydrofluoric acid is added to the raffinate to minimize the solubility of aluminum fluoride (AlF.sub.3) therein and thereby maximize the precipitation potential of AlF.sub.3. Generally this occurs when sufficient hydrofluoric acid has been added to cause the F/Al weight ratio to be within the range of from about 1.8 to about 2.2. As a result of this treatment, the raffinate is divided into an uranium-containing aqueous solution and an AlF.sub.3 precipitate which contains substantially no uranium.
    Type: Grant
    Filed: July 17, 1980
    Date of Patent: February 22, 1983
    Assignee: Sumitomo Metal Mining Company Ltd.
    Inventors: Hiroshi Ishimi, Hisaaki Shimauchi, Chuzaburo Tanaka