Zinc phosphate - Zn3(PO4)2

What is Zinc phosphate?

Zn3(PO4)2 is an inorganic chemical compound with a chemical name Zinc phosphate. It is also called Trizinc phosphate or Zinc orthophosphate or Trizinc diphosphate. It is widely used as a corrosion resistant coating applied on metal surfaces which is put as primer pigment or as a part of electroplating.

Trizinc phosphate coats better on a crystalline structure when compared to a bare metal. Therefore, a seeding agent such as sodium pyrophosphate is frequently used as a pre-treatment.

Properties of Zinc phosphate – Zn3(PO4)2


Zinc phosphate

Molecular weight of Zn3(PO4)2

386.11 g/mol

Density of Zinc phosphate

3.998 g/cm3

Melting point of Zinc phosphate

900 °C

Flash point of Zinc phosphate


Zinc phosphate structure – Zn3(PO4)2

Zinc phosphate structure

Zn3(PO4)2 Uses (Zinc phosphate)

  • Zinc phosphate is used in dentistry.
  • Used as a plating agent as well as a surface treating agent.
  • Used in the making of rubber products.
  • Used as an anti-scaling agent.
  • Used in the manufacturing of dyes.
  • Used as an additive in paints.
  • Used as a corrosion inhibitor.
  • Used in water treatment products.

Zinc phosphate Occurrence

Some of the different forms of Zinc orthophosphate are minerals such as hopeite and parahopeite. One similar mineral is tarbuttite, Zn2(PO4)(OH).

It originates from zinc phosphate cement. This cement is commonly used as a base for dental restorations. It is used for cementation of crowns, inlays, bridges, as a temporary restoration, and orthodontic appliances. It is made by mixing magnesium oxide and zinc oxide powders with a liquid which consists of phosphoric acid, buffers, and water.

Learn more about the Structure, physical and chemical properties of Zn3(PO4)2 from the experts at BYJU’S.

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