Albright & Wilson Limited

Frank Michael Cussons

Thomas A Williams

Douglas E Mather

Wet process phosphoric acid is purified by extraction with a hexanone of pentanone to form an organic extract, containing phosphoric acid, from which the acid content is recovered by treatment with water or aqueous phosphoric acid in 2 or more portions to give 2 or more purified acids, the recovery to give the last purified acid being in more than 1 countercurrent stage.

Process for purifying phosphoric acid

Phosphate values can be recovered from an organic extract which is formed by contact of wet process phosphoric acid and a water immiscible solvent, in a process in which the extract is treated with an inorganic base or a dihydrogen phosphate salt to give an acid free solvent and an aqueous solution of phosphoric acid and phosphate salt with a cation to P usually in the 0.1 - 0.5 : 1 region. The aqueous solution represents a concentrated soluble phosphate source for subsequent neutralization and conversion to e.g. tripolyphosphates.

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Cumbria, United Kingdom

Frank Michael Cussons