Puerto Rico

Ammonium Phosphate

The largest use by weight is in agriculture, as an ingredient of fertilisers. It is also used as in dry chemical extinguishers, and very widely in the field of optics due to its crystalline properties.

Synonyms
Ammonium Phosphate Monobasic, Ammonium Dihydrogenphosphate, Mono-Ammonium Phosphate, Prim-Ammonium Phosphate, MAP
Chemical Formula
H₁₂N₃O₄P
CAS Number
7722-76-1

Characteristics

Molar Weight
115.03 g/mol
Melting Point
190°C
Density
1.803 g/cc
Forms
Powder (dry), White, Granular

Uses and Applications

Key applications

  • Baking
  • Pulp and paper
  • Wine production
  • Textile handling
  • Agricultural (non-pesticide)
  • Building & Construction products
  • Electronics

Ammonium phosphates

Ammonium phosphates exist in different variants such as mono-, di- and triammonium phosphate. There are also ammonium polyphosphates. The substances differ in the number of hydrogen atoms in the phosphate. The two most common types of ammonium phosphate are monoammonium phosphate (MAP) and diammonium phosphate (DAP). Most ammonium phosphates are produced synthetically. The ammonium salts of phosphoric acid are mainly used in fertilisers and as a low-cost and low-toxicity flame retardant.

Properties of ammonium phosphates

Ammonium phosphates are salts consisting of ammonium ions and phosphate ions. They are colourless and odourless crystalline solids that dissolve well in water. Ammonium phosphates are mainly obtained by the reaction of ammonia with phosphoric acid. The specific type of ammonium phosphate produced depends on the exact reaction conditions and the mixing ratio of the starting materials.
Agriculture fertilizer tractor

Ammonium phosphates in agriculture

Ammonium phosphates are mainly used as fertilisers in agriculture. They dissolve well in water and thus offer rapid availability of the nutrients nitrogen (important for the growth and development of plants, especially leaves and stems) and phosphorus (important for root development, flowering, fruit formation and energy transfer within the plant) in high concentrations.
Ammonium dihydrogen phosphate (NH4H2PO4) is often used as a single component fertiliser in the form of a solution that is sprayed directly onto the leaves or distributed via irrigation systems. Diammonium phosphate (DAP, (NH4)2HPO4) is also a widely used fertiliser that is scattered on the soil surface in granular form or worked into the soil.
In addition, ammonium phosphates are often used in combination with other nutrients in compound fertilisers to ensure a balanced nutrient supply for plants.

Ammonium phosphates in the construction industry

Ammonium phosphates are mainly used as flame retardants in the construction industry. They increase the ignition temperature of materials and slow down the spread of flames by forming a protective layer that reduces the access of oxygen to the burning material.
The thermal decomposition of ammonium phosphates also releases non-combustible gases that reduce the formation of smoke and toxic gases during a fire. For example, ammonium phosphates protect wood and wood products such as plywood, chipboard and fibreboard from fire.
In special cements, ammonium phosphates optimise setting time and strength and increase the chemical resistance ft he cement.

Ammonium phosphates in the textile industry

In order to reduce the flammability of textiles such as clothing, home textiles (curtains, upholstery and carpets) and technical textiles (tents and protective clothing), these are treated with ammonium phosphates (impregnation, spraying and coating).
Biscuit factory worker inspecting freshly made biscuits on production line

Ammonium phosphates in the food industry

In the food industry, ammonium phosphates are used alongside ammonium bicarbonate as leavening agents in the production of baked goods such as biscuits, crackers and certain cakes. The substances allow the dough to rise by releasing carbon dioxide when heated, thus ensuring a light and airy texture.
Ammonium phosphates also regulate the pH value in certain foods, which improves their stability and shelf life: a stable pH value is important for controlling microbial activity and enzymatic processes.
In food supplements and fortified foods, ammonium phosphates serve as sources of the essential human nutrients phosphorus and nitrogen.
In certain processed foods, ammonium phosphates are used as emulsifiers and stabilisers to optimise texture and consistency. They stabilise the mixture of ingredients and prevent the separation of oil and water.
Diammonium phosphate (DAP) in particular is used in wine production during fermentation as a nitrogen supplier ort he yeast.

Ammonium phosphates in the paper industry

Ammonium phosphates are used as flame retardants in paper production. They are also used as catalysts in the bleaching process and as stabilisers in various chemical processes during pulp production, which increases the quality and stability of the end product. Last but not least, ammonium phosphates are used in forestry as fertilisers for raw material plants.

Ammonium phosphates in the electronics industry

Ammonium phosphates are used as flame retardants in the production of printed circuit boards and other electronic components.
They are also used in the production of semiconductors and other electronic components as etching and cleaning agents that remove impurities and prepare the surfaces for further processing steps.
Ammonium phosphates are also used as fluxing agents in soldering processes; they prevent the oxidation of metals during soldering.

Further areas of application for ammonium phosphates

Ammonium phosphates are the main component of so-called ABC fire extinguishers. These are versatile and effective against class A (flammable solids), B (flammable liquids) and C (fires in electrical systems) fires.