Boron trifluoride is an important organic reaction catalyst widely used in esterification, alkylation, polymerization, isomerization, sulfonation, nitration and other reactions. Widely used in the production of petroleum resins, fine chemicals, and pharmaceutical intermediates. It is an important raw material for the preparation of borides such as boron halides, elemental boron, boranes, and sodium borohydride. BF ∝ and its compounds are used as curing agents in epoxy resins. Used for anti-oxidation protection in casting magnesium and alloys.