Hydrofluoric acid HF
|
Compounds | Reactions | Production
|
| Fluorine Compounds |
| Hydrofluoric acid |
| Fluorite |
| Hydrofluoric acid HF
|
| : Highly Corrosive : Highly Toxic : |
| Hydrofluoric acid's ability to dissolve oxides makes it important in the purification of both aluminium and uranium. It is also used to etch glass, to remove surface oxides from silicon in the semiconductor industry, as a catalyst for the alkylation of iso-butane and butene in oil refineries and to remove oxide impurities from stainless steel in a process called pickling. |
| HF is also used in the synthesis of many fluorine-containing organic compounds, including teflon and refrigerants such as freon. |
| Fluorite CaF2 |
| It is an isometric mineral with a cubic habit, though octahedral and more complex isometric forms are not uncommon. |
| Fluorite gives its name to the property of fluorescence, as many samples fluoresce strongly in ultra-violet light. The fluorescence may be due to impurities such as yttrium or organic matter in the crystal lattice. Fluorite's fluorescence colour is largely dependent on where the original specimen was located. Blue is the most common colour but red, purple, yellow, green and white also occur. Fluorite also exhibits the property of thermoluminescence. |
| As well as ornamental uses, fluorite is used in the making of opalescent glass, enamels for cooking utensils, hydrofluoric acid, and as a flux in the manufacture of steel. Fluorite is also used in some high performance telescopes and camera lens elements instead of glass. Exposure tools for the semiconductor industry, make the use of fluorite for the optics for 157 nm wavelength. This wavelength is created by an excimer laser with F2 gas, and the fluorite is a unique material that has high transparency at this wavelength. It has a very low dispersion so light diffraction is far less than ordinary glass, and in telescopes it allows crisp images of astronomical objects even at high power. The name fluorite is derived from the Latin fluo, meaning "flow", in reference to its use as a flux. |