TREATMENT OF PHOSPHORIC ACID

摘要

A method for the treatment of phosphoric acid having a concentration of between 50 and 72% P205 and having magnesium ions in solution as an impurity comprising the steps of heating the acid at a pressure between 100 and 500 p.s.i. to a temperature between 100.degree.C and 180.degree.C and maintaining the acid under these conditions for a period of time to cause at least 60% (mass/mass) of the magnesium to precipitate as the magnesium acid pyrophosphate.