Patents by Inventor Yoshito Kudo

Yoshito Kudo 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: 6319483
    Abstract: It is possible to recover gallium and indium efficiently and at a low cost from solutions containing traces of gallium and indium. In particular, jarosite is produced by performing a specific treatment on a solution obtained by a two-stage neutralization treatment during the zinc leached residue treatment step of wet zinc refining, or on another solution containing traces of gallium and indium; the gallium and indium are separated and concentrated; an alkali is added to the jarosite; and the gallium is separated and concentrated by leaching. Calcium hydroxide or magnesium hydroxide is optionally added to the jarosite leached solution to perform purifying, sulfuric acid is added to the purified solution, neutralization is performed, basic gallium sulfate is precipitated, the precipitate is subjected to alkali leaching, and the gallium in the leached solution is electrolytically extracted, yielding metallic gallium.
    Type: Grant
    Filed: January 12, 2000
    Date of Patent: November 20, 2001
    Assignee: Dowa Mining Co., Ltd.
    Inventors: Yoshito Kudo, Yukiko Maruyama