Aluminum is a lightweight and ductile metal, well-known for its resistance to corrosion. It is because of this important property that aluminum is primarily used in cookware, packaging, industrial applications, construction works, and transportation systems. In aerospace, structural parts basically made from aluminum are used for their relatively low weight and high durability.
An Overview about Aluminum
Having atomic number 13 and atomic weight 26.98, aluminum is represented by the symbol 'Al'. In the modern periodic table, you will find it in group number 13 and period number 3. The color of aluminum is silvery white or dull gray, because of rapid oxidation after exposure to air. Chemically, it is non-toxic and possesses no magnetic properties. As far as occurrence is concerned, aluminum stands third in the most abundantly found chemical elements in the earth's crust (with oxygen being first and silicon second). According to scientific data, aluminum makes up 7.5 - 8.1 percent of the total weight of the earth's solid surface.
The melting point of aluminum is higher, when compared to other commonly occurring metals, like iron, copper, brass, magnesium, zinc, etc. Aluminum melting point (temperature) is recorded to be 660.37 °C (or 1220.666 °F, 933.52 K). Whereas the meting point of aluminum oxide or alumina is comparatively higher than its pure metal form, about 2,000 °C (or 3,600 °F). It is for this reason, extraction of aluminum from alumina is carried out in an electrolytic cell by the process of electrolysis.
Speaking about the boiling point of aluminum, it is recorded to be 2467.0 °C (or 4472.6 °F, 2740.15 K). Please note that these melting and boiling temperatures may be slightly different from one data to another. This lightweight metal is remarkable for its recyclable property. It can be reused in other ways without any wastage. In the recycling process, melting aluminum is a crucial step. Primary aluminum is so named when the metal is used for the first time, while its recycled form is referred to as secondary aluminum.
Even though it is well said that aluminum is resistant to corrosion, it is chemically very reactive in nature. This is evident from the fact that aluminum is hardly found as a freely available element. Rather, there are approximately 270 minerals that contain aluminum as one of their ingredients. The main ore of aluminum is bauxite (a mixture of Al2O3·xH2O and Fe2O3·xH2O), from which this metal is produced on a mass scale. Commercial extraction of aluminum from bauxite is done by Bayer process. Other than bauxite, cryolite (Na3AlF6) is an important mineral of aluminum.
Facts about Aluminum
Being one the most abundant metals in the earth's crust, there are some interesting facts associated with aluminum. For your reference, some aluminum facts are highlighted below.
- The credit for discovery of aluminum goes to Hans Christian Oersted, a Danish physicist and chemist, who produced aluminum for the first time in an impure form in 1825.
- The name aluminum is originated from the Latin word for bitter salt Alumen. And the original name was 'aluminium', which later became popular as aluminum.
- The density of aluminum metal is 2.70 grams per cubic centimeter, hence it sinks in water. But, aluminum is lighter than other metals.
- Aluminum is a primary component of soil, wherein it occurs as aluminum hydroxide (an insoluble compound). The oxide form of aluminum is used to make synthetic gemstones, such as rubies and sapphires.
- Exposure to aluminum in excess amounts (particularly in ionic state) is hazardous, resulting in nervous damage, dementia, respiratory disorders, and other medical complications.
Aluminum after oxidation is very stable (unlike iron), which makes it an excellent metal for various applications. The thin oxidized layer present in the outer surface provides resistance to water, acid, and similar reactive agents. Owing to its characteristic properties, aluminum is the second most widely used metal, next to iron.