How is fertilizer made using sulfuric acid?
The large percentage of the phosphoric acid in fertilizer phosphates is produced from sulfuric acid and phosphate rock. This phosphoric acid, known as “wet-process” acid, is then used in the manufacture of triple superphosphate, ammonium phosphates and other high analysis fertilizer products. The primary chemical reaction in the production of wet process phosphoric acid is between the calcium phosphate constituent of the phosphate rock and sulfuric acid to form phosphoric acid and calcium sulfate. The principal difference in the processes used throughout the world is the degree of hydration of the calcium sulfate, which can be varied by changing the temperature and P2O5 concentration in the reaction. The most popular process which is used by the Florida producers is known as the dihydrate process in which gypsum is precipitated. Phosphoric acid production by the wet process requires three main operations: reaction between the phosphate rock and sulfuric acid, separation of the gypsum f
