What is Aluminium Fluoride
Aluminium fluoride or also known as Aluminium trifluoride is an inorganic compound with the formula of AlF3.xH2O. As seen in the formula, this compound occurs as a hydrate containing x molecule of water. Aluminium fluoride is a white crystal/powder, which sublimes at 1272 degree celcius. This compound is practically insoluble in cold water, soluble in hot water, and and insoluble in most organic solvents.
For a small laboratory scale, alumina trihydrate or aluminium hydroxide (Al(OH)3) is mixed with hydrofluoric acid (HF) to produce aluminium fluoride. The reaction is shown below:
Al(OH)3 + 3HF à AlF3 + 3H2O
- Trihydrate (dry state)
This method is almost the same with the regular trihydrate, however the hydrofluoric acid used in this method is in gas form. The reaction performs the same as the other trihydrate but in the dry condition.
- Acidification with fluorosilic acid (H2SiF6)
Fluorosilic acid is combined with alumina trihydrate (Al(OH)3). This method is commonly used in the industry due to the cost is the lowest compared to the other two methods before. Fluorosilic acid itself can be easily obtained from fertilizer products and phosporic acid production.
The Uses of Aluminium Fluoride
· Aluminium metal production
One of the aluminium compound is being extracted from aluminium oxide using electric current or electrolysis through the melted compound. After the extraction, aluminium fluoride is added to the raw materials used to reduce the temperature at which the reaction performs to below 1000 degree celcius and improves the conductivity of the melted compound. Thus, aluminium fluoride helps the manufacturer to lower the energy use in the manufacturing process.
· Ceramic and glass production
Aluminium fluoride plays a great role in ceramic production as it is the main chemical compound used in glazes for finished products. Besides that, aluminium fluoride is also used to create refractory ceramic products. In glass industry, aluminium fluoride is used as a filler.
- Low index optical thin film production
Aluminium fluoride is used as the raw material together with magnesium fluoride for the low index optical thin film production. Aluminium fluoride is a better option due to it has a higher UV transparency requirement.
- Catalyst for organic compounds synthesis
Aluminium fluoride can be used as a catalyst for organic compound synthesis process as the synthesis itself is a chemical reaction to produce new chemical from simple chemical or reactants.
- Inhibitor of fermentation
Aluminium fluoride can be used to inhibit the fermentation process which is very useful in the beer and wine making industries.