Patents Examined by Oscar R. Vertig
  • Method for purifying phosphoric acid
    Patent number: 3970741
    Abstract: A method for purifying phosphoric acid obtained with sulfuric acid acting on natural phosphates, comprises extracting the phosphoric acid with a mixed solvent formed essentially by 95% to 50% by volume of an ether containing 5 to 7 carbon atoms, and by 5% to 50% by volume of at least one of the esters resulting from the reaction of the phosphoric acid with alcohols having 3 to 5 carbon atoms.
    Type: Grant
    Filed: January 31, 1974
    Date of Patent: July 20, 1976
    Assignee: "Societe de Prayon"
    Inventor: Engelhard Wilhelm Pavonet