Patents by Inventor Yushiro Hirai

Yushiro Hirai 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).

  • Method of operating a copper smelting furnace
    Patent number: 6436169
    Abstract: In a method of operating a copper smelting furnace, wherein a ferrous substance containing more than 80 wt. % metallic iron having a specific gravity of 3.0-8.0 and particle diameter of 0.3-15 mm is added to copper smelting slag containing Fe having an oxidation-reduction number of 3+ and to the Fe3O4 in the intermediate layer, thereby deoxidizing the Fe3O4 to FeO, the method reduces the Fe3O4 within the slag layer and the Fe3O4 generated in the intermediate layer between the slag layer and the matte layer. So that their viscosity is reduced and separation rate is increased, thus increasing the yield rate of useful metal, and the problems that originate in the intermediate layer are eliminated.
    Type: Grant
    Filed: March 5, 2001
    Date of Patent: August 20, 2002
    Assignee: Nippon Mining & Metals Co., Ltd.
    Inventors: Yushiro Hirai, Mitsumasa Hoshi
  • Method of operating a copper smelting furnace
    Publication number: 20010049982
    Abstract: In a method of operating a copper smelting furnace, wherein a ferrous substance containing more than 80 wt. % metallic iron having a specific gravity of 3.0-8.0 and particle diameter of 0.3-15 mm is added to copper smelting slag containing Fe having an oxidation-reduction number of 3+ and to the Fe3O4 in the intermediate layer, thereby deoxidizing the Fe3O4 to FeO, the method reduces the Fe3O4 within the slag layer and the Fe3O4 generated in the intermediate layer between the slag layer and the matte layer. So that their viscosity is reduced and separation rate is increased, thus increasing the yield rate of useful metal, and the problems that originate in the intermediate layer are eliminated.
    Type: Application
    Filed: March 5, 2001
    Publication date: December 13, 2001
    Inventors: Yushiro Hirai, Mitsumasa Hoshi