Magnesium fluorosilicate (MgSiF₆), also known as magnesium hexafluorosilicate, is an inorganic compound. It usually occurs in the form of colorless or white rhombic or needle-like crystals, odorless, with a relative density of 1.788 g/cm³. It has a melting point of 120°C and decomposes at this temperature. 

Magnesium fluorosilicate is not easily deliquescent, but it can be weathered and lose crystal water. When the temperature exceeds 80°C, it dehydrates and decomposes and releases silicon tetrafluoride gas. It is easily soluble in water and soluble in dilute acids, but insoluble in hydrofluoric acid and alcohols. Its aqueous solution is acidic.

Uses of Magnesium Fluorosilicate

1. Concrete hardener and waterproofing agent: Magnesium fluorosilicate can react with calcium ions in concrete to form strong hydrated calcium silicate, thereby improving the hardness and strength of concrete, while enhancing its waterproof performance.

2. Fluorine weathering treatment on the surface of silica buildings: Magnesium fluorosilicate can be used to treat the surface of silica buildings to enhance its durability and aesthetics.

3. Ceramic manufacturing: In ceramic production, magnesium fluorosilicate can be used as a flux to help reduce the sintering temperature and improve the sintering performance of ceramics.

4. Fabric insect repellent treatment: Magnesium fluorosilicate can be used as an insect repellent for fabrics to protect fabrics from insect pests.

5. Insecticides: Magnesium fluorosilicate can also be used as one of the active ingredients of pesticides in agriculture and public health.

6. Other industrial applications: In addition to the above uses, magnesium fluorosilicate may also be used in the production of abrasives, abrasives, and other industrial chemicals.