Sodium fluorosilicate (Na₂SiF₆) is an inorganic compound that belongs to coordination salts or complex salts. It is a white crystalline powder with moisture absorption and a density of 2.68 g/cm³. Sodium fluorosilicate has a wide range of applications in industry, such as metal smelting, ceramic industry, production of fireproof materials, Portland cement production, etc.

1. Metal smelting: Sodium fluorosilicate is used as a flux for metals such as aluminum and copper, helping to reduce the melting point of metals and improve melting efficiency.

2. Ceramic industry: It is used as a component of glazes and porcelain tires to enhance the hardness and luster of ceramic products.

3. Fireproof materials: In some fireproof materials, sodium fluorosilicate can be used as an additive to improve the fire resistance of materials.

4. Cement production: In the production of Portland cement, sodium fluorosilicate helps to improve the performance of cement.

5. Pharmaceutical field: It can be used as a raw material for the manufacture of certain drugs (such as sodium aluminum fluorosilicate gastric powder, sodium fluorosilicate lotion), as well as as a stabilizer and buffer in biological agents.

6. Environmental protection: As a sewage treatment agent, sodium fluorosilicate can accelerate the precipitation of suspended solids, which is used to purify sewage, and also has the function of anti-rust to protect the surface of steel.

7. Food industry: Although uncommon, sodium fluorosilicate can also be used as a food additive in some cases.

8. Agriculture: In agricultural production, sodium fluorosilicate can be used as an insecticide and herbicide.

9. Other applications: including as an additive in glass manufacturing, vegetable cleaning agent, etc.