Patents by Inventor Robert B. Calvin

Robert B. Calvin 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).

  • Process of manufacturing non-gelling suspension liquid fertilizers
    Patent number: 4127400
    Abstract: A process of manufacturing liquid fertilizer from ortho phosphoric acid is described herein. Specifically, the process involves extracting ortho phosphoric acid from phosphate rock using sulfuric acid in the usual manner. The ortho phosphoric acid is then concentrated to a P.sub.2 O.sub.5 content of 30-58% by weight. The wet process ortho phosphoric acid is then ammoniated at a carefully controlled pH in a range of about 3.0 to 5.5. Water and commercial clays are added to the ammoniated phosphoric acid during ammoniation or after ammoniation. A stable non-gelling suspension fertilizer results.
    Type: Grant
    Filed: October 21, 1974
    Date of Patent: November 28, 1978
    Assignee: Stauffer Chemical Company
    Inventors: Alfred W. Petersen, Robert B. Calvin