Patents by Inventor Barbara T. Booker

Barbara T. Booker 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: 5085836
    Abstract: A method to reduce dissolved silver present in spent, waste, photographic processing fluids containing thiosulfate, is described. This process involves adjusting the pH to a low level prior to the addition of finely ground steel to the solution. With the pH at the low level, e.g. 2.5, the reaction of dissolved silver to precipitated silver, is facilitated. However, the pH must then be raised or neutralized, e.g. 7-8.5, in order to insure that the dissolved silver is essentially all precipitated. This material can now be safely shipped without treatment as a hazardous material and, after filtering the solids therefrom, can be safely disposed.
    Type: Grant
    Filed: December 3, 1990
    Date of Patent: February 4, 1992
    Assignee: E. I. du Pont de Nemours and Company
    Inventor: Barbara T. Booker