What are the main uses of hydrofluoric acid?

Due to its ability to dissolve oxides, hydrofluoric acid plays a crucial role in the purification of aluminum and other metals. It is also used to etch glass, allowing for the engraving of patterns, scales, and text. In the semiconductor industry, it is employed to remove oxides from silicon surfaces. In refineries, it serves as a catalyst for the alkylation reaction between isobutane and n-butene. Hydrofluoric acid is also utilized in the "acid immersion" process to remove oxygen-containing impurities from stainless steel surfaces. Additionally, hydrofluoric acid is used in the synthesis of various fluorine-containing organic compounds, such as Teflon (polytetrafluoroethylene) and refrigerants like Freon.