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
Abstract: An improved method of making finely divided, dry metal halides and sulfides, such as chromium chloride and chromium sulfide which are suitable for use as lubricants and wear-proof and corrosion-proof agents for metals.
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.
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