Hydrogen Fluoride Uses

Fluorine, the most electronegative element in the periodic table, when combined with hydrogen, under controlled temperatures and pressure, forms hydrogen fluoride (HF). Being a colorless gas with quite an unpleasant odor, most of the properties of HF are influenced by the fact that it contains fluorine, a halogen group compound whose elements have typical salt like properties.

The presence of a hydrogen atom in HF imparts hydrogen bonding strength to molecules of HF in liquid form, which is the reason behind a higher boiling point of HF relative to compounds of the same species.

The boiling point of HF is 19.5ºC, that means, it can boil even if the temperature crosses a nominal value of 20ºC! Converting HF into a solid mass is very difficult because it freezes at -83.1ºC, which is an exceptionally low temperature.

Due to several physical and chemical properties, HF in liquid form is used in various industries like pharmaceuticals, refrigerants, fluorescent bulbs, and aerosols.

HF is widely used in the synthesis of fluorocarbons like Freons and Teflons (a brand of DuPont, one of the world's largest chemical companies by market capitalization). These fluorocarbons are used as refrigerants, aerosols, propellants and solvents in the industrial world. Most fluorocarbons are produced by reacting long chains of hydrocarbons with hydrogen fluoride and some catalyst.

Aluminum fluoride is used in the industrial production of Aluminum. It is produced by reacting hydrogen fluoride gas and aluminum oxide to form aluminum fluoride, AlF₃.

In the process of industrial production of Aluminum, cryolite is used as an important electrolyte in the smelting operation. Cryolite is made up of sodium, aluminum and fluoride.

Hydrogen fluoride is found in many drugs like Prozac. It is a fact that the increasing use of HF and fluorine compounds in drinking water, toothpastes and beverages have raised concerns of a larger section of environmentalists in the US.

In nuclear reactors, uranium is essential for producing energy. In a process called, uranium enrichment process, hydrogen fluoride along with fluorine is reacted with hydrogen oxide to yield uranium hexafluoride, that is believed to be of great value in nuclear reactor operations.

Being one of the worst chemical poisons, HF finds extensive use in manufacturing weapons of mass destruction. As stated earlier, use of HF in a nuclear reactor obviously makes it a deadly tool of mass destruction.

As aforementioned, HF is very harmful and if ingested, it requires immediate medical help. Pesticides that are meant to kill insects contain HF as an integral component. HF kills insects or pests instantly. This is why, it is advised keep children out of reach of pesticide chemicals.

When HF dissolves in water, its solution is called hydrofluoric acid, which finds its use in higher industrial chemistry. Compared to other acids, hydrofluoric acid is a weak acid but even then in liquid or dense gaseous forms it has the ability to harm the eyes and skin.

Hydrofluoric acid finds its use in the following ways:

• It is an integral part of compounds like Teflon, Freon and other types of polymers.
• For dissolving metals and semi - metals.
• HF acid is also used in etching glasses, refining oils and cleaning stainless steel.

The uses of hydrogen fluoride in the industry, as you can observe are many. As the chemical industry has opened up for using hydrogen fluoride in different forms in beverages and toothpastes, questions regarding fluoride compounds and their hazardous affects have become prominent.