Patents by Inventor Hung-Kei H. Lam

Hung-Kei H. Lam 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: 4113832
    Abstract: A fully integrated process is provided for the recovery of valuable components from waste materials generated in electrolytic aluminum reduction systems. The waste materials, such as spent pot linings, channel and trench cleanings, floor sweepings and spent alumina from offgas purifying dry scrubbers, are combined, then pyrohydrolyzed at elevated temperature. Fluoridic values, such as NaF and HF can be recovered from the offgas generated by pyrohydrolysis, while alumina and Na.sub.2 O values, or if desired, sodium aluminate, is reclaimed from the solid residue of pyrohydrolysis.The fluoridic values from the pyrohydrolysis offgas can be used for the manufacture of both electrolytes for aluminum reduction cells and also for the production of anhydrous HF. The alumina from the pyrohydrolysis residue can be reclaimed by a Bayer process-type leach with a caustic solution and the recovered high purity alumina utilized, for example, as reduction cell feed and/or for scrubbing reduction cell offgases.
    Type: Grant
    Filed: November 28, 1977
    Date of Patent: September 12, 1978
    Assignee: Kaiser Aluminum & Chemical Corporation
    Inventors: Norman Bell, John N. Andersen, Hung-Kei H. Lam