Purification of wet process phosphoric acid
AssigneeAlbright & Wilson Limited
InventorsEdward J. Lowe, Arthur Wilson, Michael W. Minshall
Life of this patent
Estimating the term…
Abstract
Wet process phosphoric acid is heated, preferably in carbon apparatus, by passing alternating current through the acid, to concentrations above 80% P.sub.2 O.sub.5 and preferably temperatures above 500.degree. C. to remove sulphate and fluoride and convert organic and basic impurities into a filterable precipitate: the acid is separated from the precipitate to provide a high purity crystallizable product.
Claims25
A method for the production of phosphatic derivatives of wet process phosphoric acid which comprises heating wet process phosphoric acid in carbon apparatus to evaporate water therefrom to leave a concentrated acid by direct electrical resistance heating by passing an alternating current through said wet process acid, until the concentration of said concentrated acid is above 80% by weight P.sub.2 O.sub.5, precipitating solid impurities from said concentrated acid and separating the precipitated impurities.
Dependencies are inferred from the claim text.