How are phosphate fertilizers produced?

Phosphate fertilizer production: Phosphate rock mining - apatite (Ca5(PO4)3F) is primary source. Phosphoric acid production - wet process: rock + H2SO4 = H3PO4 + CaSO4 (gypsum byproduct). DAP (diammonium phosphate) - neutralize phosphoric acid with ammonia: H3PO4 + 2NH3 = (NH4)2HPO4. Contains 18% N, 46% P2O5. MAP (monoammonium phosphate) - H3PO4 + NH3 = NH4H2PO4. Contains 11% N, 52% P2O5. TSP (triple superphosphate) - rock + H3PO4 = Ca(H2PO4)2. Contains 46% P2O5, no nitrogen. NPK compounds - blend or chemical combination of N, P, K sources. Environmental issues: gypsum disposal, fluorine emissions, heavy metals in rock. Process optimization focuses on P2O5 recovery and grade.