Colloid Systems Having Specified High Purity (e.g., Ultra-pure Silica) Patents (Class 516/921)
  • Patent number: 7012209
    Abstract: A method of collecting gold by flowing water over a gold collecting medium located in a sluice to induce a positive surface charge on the gold collecting medium. Feeding gold laden material into the sluice with the flowing water to induce a negative surface charge on gold particles of the gold laden material and create a slurry. Setting the flow rate of the slurry into the sluice such that the gold particles are attracted to the gold collecting medium. Finally, collecting the gold particles attracted to the gold collecting medium from the gold collecting medium. A gold separation device having a sluice having an input end and an output end; a water input directed into the input end of the sluice; and a gold collecting medium in the sluice. The gold collecting medium being of a material which incurs a positive surface charge when immersed in water.
    Type: Grant
    Filed: January 16, 2004
    Date of Patent: March 14, 2006
    Inventor: Wayne W. Loewen
  • Patent number: 6328894
    Abstract: A process to purify and classify a dispersion containing stabilized particles having counterions and ions as well as free species is disclosed. The solution may comprise an aqueous media, a solvent media, or a combination of both and can include more than one type of aqueous and/or solvent solutions. The process includes at least the steps, in any order, of substantially removing the particles having sizes above about 1 micron, preferably above 0.5 micron; substantially removing the free species; and exchanging at least a portion of the counterions that are a part of the stabilized particles. The process disclosed is especially useful in purifying dispersions where the ionic stabilized colloidal particles are carbon black having attached organic groups comprising at least one ionic group, or at least one ionizable group, or mixtures thereof.
    Type: Grant
    Filed: January 29, 1999
    Date of Patent: December 11, 2001
    Assignee: Cabot Corporation
    Inventors: Michael K. Chan, Joseph E. Johnson, John Mathew, Friedrich K. von Gottberg
  • Patent number: 6001270
    Abstract: Sticky high water content gelled fire extinguisher compositions hold the antage of providing a high water content, slightly viscous (sticky) gel with flow properties similar to water. The ability of this material to stick to burning surfaces is what sets it apart from water extinguishers. Not only are fires extinguished, but also surfaces are cooled by the sticky gel as the water evaporates. The basic gelled fire extinguisher composition is comprised of about 88 weight percent water and about 12 weight percent of a 7 nanometer particle size silicon dioxide gellant. The silicon dioxide gellant is available as EH5 tradename by Cabot for this silicon dioxide gellant. Other ingredients such as dispersants, wetting agents and flame retardants can be used as additives in combination with the gelling agent. The actual gel system is inexpensive, made from readily available ingredients and easily prepared.
    Type: Grant
    Filed: March 16, 1998
    Date of Patent: December 14, 1999
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventors: William D. Stephens, Leo K. Asaoka, Christi L. Salter