To cope with the wide range of raw phosphoric acid qualities produced from phosphate rock, and the growing needs for high quality end products, users are increasingly interested in the purification of their phosphoric acid. From the various purification techniques that are available, three have been selected and reviewed: chemical purification, for the production of sodium or ammonium phosphates; phosphoric acid purification by ion exchange on selective resins; and by solvent extraction. The basic working principles of each of the three processes is described.
Thomas Henry, Prayon Technologies, Engis, Belgium.
18 pages, 1 figure, 4 tables, 3 reference