Patents by Inventor John I. Choi

John I. Choi 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).

  • Production of chromium (III) compounds
    Patent number: 4528175
    Abstract: A process of preparing chromium (III) compounds from chromate and/or dichromate salts by forming a mixture of such salts, an acid, water and a reducing agent. Additional acid is added to the mixture which is then cooled selectively precipitating the salt of the anion of the acid and the cation of the chromate and/or dichromate salts which is separated from the solution containing the desired chromium (III) compound.
    Type: Grant
    Filed: November 18, 1982
    Date of Patent: July 9, 1985
    Assignee: Allied Corporation
    Inventors: James F. Walther, John I. Choi
  • Recovery of soluble alumina values from alumina bearing ores
    Patent number: 4339415
    Abstract: A process for the recovery of soluble alumina values from alumina-bearing ores comprising simultaneously contacting a stream containing an effective amount of a reducing agent such as SO.sub.2 and a stream containing an effective amount of an oxidizing agent such as Cl.sub.2 with an aqueous slurry of the alumina-bearing ores for a time sufficient to remove at least about 50 weight percent of the soluble alumina values from said ores is disclosed.
    Type: Grant
    Filed: December 5, 1980
    Date of Patent: July 13, 1982
    Assignee: Allied Corporation
    Inventors: John I. Choi, Bruce E. Kurtz, Anatoli Omelian