Phosphates

Definition

phosphates: Salts based formallyon phosphorus(V) oxoacids and inparticular salts of phosphoric(V)acid, H₃PO₄. A large number of polymericphosphates also exist, containingP–O–P bridges. These are formedby heating the free acid and its saltsunder a variety of conditions; as wellas linear polyphosphates, cyclic polyphosphates and cross-linkedpolyphosphates or ultraphosphatesare known.

Agricultural Uses

Salts based on phosphorus (V) oxyacids with alkali or metal oxide, and in particular, salts of phosphoric or orthophosphoric acid (H₃PO₄) are called phosphates. There also exist many polymeric phosphates containing P-O-P bridges formed by heating free acid and its salts under a variety of conditions. The fused and noncrystalline phosphate products are available for use in fertilizers, as are linear polyphosphates, cyclic polyphosphates and cross-linked polyphosphates or ultra phosphates.
Phosphates are applied to the soil as phosphatic fertilizers to supply phosphorus to crops. Certain organic phosphates are used as insecticides.

Safety Profile

Alkali metal phosphates are strong caustics and therefore powerful irritants. Superphosphate is Ca(H2po4)2/CaS04. Triple superphosphate contains P2O5. Both are used as ferulizers. Organophosphates are often hlghly toxic pesticides. For an example of organic phosphates, see PARATHION. See also indvidual phosphates.

Raw materials

Preparation Products