The reaction between apatite and sulfuric acid produces phosphoric acid and gypsum in different hydrated forms depending on the production technology.
Apatite, with general formula Ca5(PO4)3(OH, F, Cl), represents a group of phosphate minerals, usually referred to hydroxyapatite, fluorapatite and chloroapatite, named for the high concentration of OH-, F- and Cl- ions, respectively, in the crystal. It is the mineral raw material of phosphate fertilizers.
Phosphoric acid has several industrial applications, one of the most prominent being the production of solid phosphorus and nitrogen source fertilizers made by reacting phosphoric acid and liquid ammonia: MAP (monoammonium phosphate) and DAP (diammonium phosphate).
