Patents by Inventor Houyuan Liu

Houyuan Liu 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: 5236491
    Abstract: Geothermal brines are passed through a bed of an anionic resin selective to the removal of boron while maintaining a pH value between about 4 to 5.5 to load the boron on the resin from which the boron is thereafter recovered. If the brine contains large quantities of constituents have Lewis acidities greater than boric acid, these constituents are preferably removed before the boron is recovered. The invention is particularly applicable to geothermal brines of temperature above ambient, e.g., 90.degree. C. and above, such as 95.degree. C. and above.
    Type: Grant
    Filed: October 28, 1992
    Date of Patent: August 17, 1993
    Assignee: BHP Minerals International Inc.
    Inventors: Willem P. C. Duyvesteyn, Manuel R. Lastra, Houyuan Liu
  • Patent number: 5178848
    Abstract: Lithium metatungstate as a new composition of matter and the production thereof are disclosed. A solution of lithium monotungstate is treated with an extractant to remove sufficient lithium ions to produce a dilute solution of lithium metatungstate and the dilute solution is then concentrated. Lithium metatungstate solutions are more dense than other alkali metal metatungstates and have lower viscosities which properties make the solutions highly useful for heavy media separations.
    Type: Grant
    Filed: June 25, 1991
    Date of Patent: January 12, 1993
    Assignee: BHP-Utah International Corp.
    Inventors: Willem P. C. Duyvesteyn, Houyuan Liu, Nicholas L. Labao, Purusotam L. Shrestha