Patents by Inventor Stephen Zapisek

Stephen Zapisek 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).

  • Gold recovery process
    Patent number: 4543169
    Abstract: A method is described for precious metal recovery from acidic precious metal-cyanide solutions by means of a weakly-basic anion-exchange material comprising a polymeric felt incorporating radiation-grafted pyridinyl functional groups.
    Type: Grant
    Filed: August 31, 1983
    Date of Patent: September 24, 1985
    Assignee: RAI Research Corporation
    Inventors: Vincent F. D'Agostino, Joseph Y. Lee, Stephen Zapisek, George Schore
  • Copper recovery process
    Patent number: 4500396
    Abstract: A method is described for metal recovery from basic ammoniated metal solutions by means of a weakly-acidic cation-exchange material comprising a polymeric felt incorporating radiation-grafted monomers comprising carboxylic acid functional groups.
    Type: Grant
    Filed: January 26, 1984
    Date of Patent: February 19, 1985
    Inventors: Vincent F. D'Agostino, Joseph Y. Lee, Stephen Zapisek, George Schore