Group Vib Metal (cr, Mo, Or W) Patents (Class 423/53)
Ion exchanging or liquid-liquid extracting (Class 423/54)
Forming insoluble substance in liquid (Class 423/55)
Volatizing (Class 423/59)
Forming compound containing plural metals (Class 423/61)
  • Treatment of chromium ore residues to suppress pollution
    Patent number: 3937785
    Abstract: Method for treating solid ore residue obtained by production of chromium chemicals from chromite ore, to reduce leaching of chromium compounds therefrom after disposal, which involves reducing the particle size of the residue prior to disposal so that at least about 20 percent by weight of the residue passes through a 200 mesh (U.S.) screen.
    Type: Grant
    Filed: September 17, 1974
    Date of Patent: February 10, 1976
    Assignee: Allied Chemical Corporation
    Inventors: Alan Brian Gancy, Christian Albert Wamser
  • Process for the manufacture of ammonium tungstate ammonium paratungstate, ammonium metatungstate and hydrated tungsten trioxide
    Patent number: 3936362
    Abstract: Ammonium tungstate, ammonium paratungstate, ammonium metatungstate or hydrated tungsten trioxide is produced by passing tungstate anions through an anion exchange membrane into an aqueous solution containing ammonium cations under the driving force of an electrical potential for a time sufficient to achieve a pH within the range in which the desired tungsten compound will form.
    Type: Grant
    Filed: June 10, 1974
    Date of Patent: February 3, 1976
    Assignee: GTE Sylvania Incorporated
    Inventors: Clarence D. Vanderpool, Martin B. MacInnis, James C. Patton, Jr.
  • Process for producing alkali metal chromates and dichromates
    Patent number: 3932598
    Abstract: An improved process for producing alkali metal chromates and dichromates wherein ferrochrome alloy containing at least 1% carbon by weight is reacted with a molten mixture of an alkali metal nitrate and an alkali metal carbonate at a temperature of at least 350.degree.C. The ferrochrome alloy can be prepared by smelting chromite ore in the presence of carbon.
    Type: Grant
    Filed: April 24, 1970
    Date of Patent: January 13, 1976
    Inventors: Hugh S. Cooper, deceased, Henry J. Rand, executor