AlF3

Aluminum trifluoride, with the chemical formula AlF3, is an inorganic compound consisting of aluminum cations and fluoride anions. It is typically encountered as a white crystalline solid or powder and exists in several polymorphic forms, the most common being present at ambient conditions.

AlF3 has a very high melting point, around 1290°C, and is relatively insoluble in water. It is hygroscopic and slowly hydrolyzes in moist air, forming aluminum oxyfluoride species and hydrogen fluoride. In the laboratory and industry, it is usually prepared by fluorination of aluminum oxide or aluminum hydroxide with hydrofluoric acid or other fluorinating agents at elevated temperature.

Industrially, aluminum fluoride is a precursor and flux in various processes. It is a component of cryolite (sodium aluminum fluoride, Na3AlF6), a material used to lower the melting point of alumina during the production of aluminum by electrolysis. AlF3 is also employed as a fluorinating agent and as a Lewis acid catalyst in certain organic syntheses and polymerization reactions. In ceramics and glassmaking, fluoride-containing fluxes that include AlF3 help reduce melting temperatures and modify properties.

Safety and handling: AlF3 is corrosive and can cause irritation to skin, eyes, and the respiratory tract. Fluoride-containing compounds can be toxic, and hydrofluoric acid hazards apply if hydrolysis products are formed. Proper dry handling and storage away from moisture are recommended to minimize hydrolysis and related risks.