REMOVING CATIONIC IMPURITIES FROM WET PROCESS ACID

摘要

A method of removing aluminum, magnesium, iron and other impurities from wet process phosphoric acid is provided. The method comprises partially ammoniating the acid and reacting the acid with a fluoride ion donating compound to precipitate aluminum- and magnesium-containing ralstonite and ammonium fluorosilicate which can be easily separated from the acid thereby producing a partially ammoniated wet process phosphoric acid of reduced impurities content.