Sodium tungstate dihydrate (Na₂WO₄•2H₂O) is a colorless or white orthorhombic crystal, soluble in water but insoluble in ethanol and acid, slightly soluble in ammonia. Its main uses include as a raw material for the manufacture of tungsten metal, tungstic acid and tungstate, as well as as mordants, pigments, catalysts, fabric fire retardants, etc.

1. Raw materials: Sodium tungstate dihydrate is used as an important raw material for the manufacture of tungsten metal, tungstic acid and other tungstate products.

2. Mordant: In the textile industry, sodium tungstate dihydrate can be used as a mordant to help the dye better fix on the fiber.

3. Pigment: In the ceramic and glass industry, it is used as a pigment, especially in the production of glass and ceramic products containing special colors.

4. Catalyst: In the chemical industry, sodium tungstate dihydrate can be used as a catalyst to facilitate the progress of certain chemical reactions.

5. Fabric fire retardant: It can also be used as a fire retardant for fabrics to improve the fire resistance of fabrics.

6. Electroplating: In the electroplating industry, sodium tungstate dihydrate can be used in the electroplating process, especially in applications where tungsten plating is required.

7. Other applications: In addition to the above uses, sodium tungstate dihydrate may also be used in agriculture, medicine, scientific research and other fields.