Aluminium dihydrogen phosphate, also known as aluminium hydrogen phosphate or aluminium orthophosphate (chemical formula: Al(H?PO?)?), has several applications, especially in the fields of materials science, chemistry, and agriculture. Some of the main applications include:

1. Agriculture and Fertilizers:

• Aluminium dihydrogen phosphate is sometimes used as a component in fertilizers. Phosphate is an essential nutrient for plants, and its combination with aluminium can help improve the availability of phosphate to plants in certain soil conditions.

2. Catalysis:

• This compound can be used as a catalyst in certain chemical reactions, especially those involving phosphate chemistry or in organic reactions requiring acidic conditions.

3. Water Treatment:

• Aluminium compounds like aluminium dihydrogen phosphate can be used in water treatment processes. They may help in removing impurities by flocculation or act as coagulants in water purification.

4. Ceramics and Refractories:

• Aluminium dihydrogen phosphate is sometimes used in the manufacture of ceramics, particularly as a binder in the production of refractories, which are materials resistant to high temperatures. The phosphate groups can help improve the material's performance in high-heat environments.

5. Analytical Chemistry:

• It may be used in laboratory settings for analytical purposes, particularly in studies related to phosphates or aluminium-based compounds.

6. Flame Retardants:

• Some forms of aluminium phosphates, including aluminium dihydrogen phosphate, can be used in flame retardants, though this is a more specialized application.

Aluminium dihydrogen phosphate is generally less common in everyday applications compared to other aluminium compounds like aluminium oxide (alumina), but it still finds niche uses in specialized fields.