Patents by Inventor Andries Jelsma

Andries Jelsma 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 for making alkali metal phosphate solutions containing little vanadium
    Patent number: 4632812
    Abstract: Alkali metal phosphate solutions containing little vanadium are made from phosphoric acid containing vanadium. To this end, a negative redox potential is established in the phosphoric acid by addition of a reductant, the acid is partially neutralized and an alkali metal-phosphorus-molar ratio between 0.85 and 1.0 is established, the partial neutralization being continued over a period of at least 10 minutes. The partially neutralized acid is not filtered intermediarily and the alkali metal/phosphorus-molar ratio is increased to 1.9 to 2.1 in a second neutralization stage, collected precipitate is separated and processed, if desired.
    Type: Grant
    Filed: October 1, 1985
    Date of Patent: December 30, 1986
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Johannes-Wilhelmus Kinneging, Wouter Roos, Bernardus J. Damman, Andries Jelsma, Raban von Schenck