Patents by Inventor Nobuyoshi Iyatomi

Nobuyoshi Iyatomi 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: 6337061
    Abstract: For the purpose of efficiently and easily regenerating a sulfuric acid solution having a high concentration and a low impurity content from a metal sulfate-containing waste sulfuric acid solution and waste liquor formed during acid cleaning which are discharged from titanium (IV) oxide-production process carried out according to the sulfuric acid method, titanium present in the metal sulfate-containing waste sulfuric acid solution is removed through a solvent-extraction treatment and then the solution obtained after the solvent-extraction is subjected to a diffusive dialysis treatment.
    Type: Grant
    Filed: March 28, 1995
    Date of Patent: January 8, 2002
    Assignee: Nittetsu Mining Co., Ltd.
    Inventors: Nobuyoshi Iyatomi, Yasuie Mikami
  • Patent number: 5531906
    Abstract: A process for treating sodium hydroxide waste liquor containing aluminum, comprising the steps of: adding, to aluminum-containing sodium hydroxide waste liquor, at least one of MgO and Mg(OH).sub.2 in an amount of 0.5 to 3 moles with respect to 1 mole of aluminum to cause a reaction at 70.degree. C. or more; and separating and removing a precipitated magnesium-aluminum compound is disclosed. The present invention makes it possible to recover recyclable sodium hydroxide from an aluminum-containing sodium hydroxide waste liquor. Even if the recovering procedure is repeated, no carbonate ions are accumulated. Therefore, it is possible to prevent degradation of the treating solution containing sodium hydroxide. Further, the by-product is a useful compound, and thus, there is no problem in the reprocessing or disposal of the by-product.
    Type: Grant
    Filed: August 1, 1994
    Date of Patent: July 2, 1996
    Assignee: Nittetsu Mining Co., Ltd.
    Inventors: Susumu Takayama, Yasuie Mikami, Nobuyoshi Iyatomi, Minoru Orikasa
  • Patent number: 5489423
    Abstract: In order to efficiently and easily recover a spent sulfuric acid exhasuted, for example, in an acid washing liquid or in producing titanium dioxide by a sulfate method in a large amount, as highly concentrated sulfuric acid, bivalent iron ions in the spent sulfuric acid containing metal sulfate are first oxidized into trivalent iron ions, hydrochloric acid is added to such a liquid and then solvent extraction is carried out.
    Type: Grant
    Filed: October 29, 1992
    Date of Patent: February 6, 1996
    Assignee: Nittetsu Mining Co., Ltd.
    Inventors: Yasuie Mikami, Nobuyoshi Iyatomi