What is Aluminum: Properties, uses and history
What is aluminum？
Aluminum is a silvery-white metal and is the 13th element in the periodic table. Aluminum is the most abundant metallic element in the earth’s crust and the most widely used non-ferrous metal. Due to its chemical activity, aluminum never occurs as a metal in nature. Concentrated in the outer 16 kilometers (10 miles) of the Earth’s crust, it accounts for about 8% of its weight; it is second only to oxygen and silicon. The name aluminum is derived from the Latin alumen, used to describe potassium alum or potassium aluminum sulfate.
This table below shows the chemical and physical properties of aluminum metal:
| items | Element Properties |
|---|---|
| Chemical Symbols | Al |
| atomic number | 13 |
| atomic weight | 26.9815386(7) |
| physiological state | Silver-white light metal (solid, at room temperature and pressure) |
| density | 2.70 g/cm³（or 2.698 * 10³ kg/m³ at 25℃） |
| melting point | 660.32 °C |
| boiling point | 2327 °C |
| valence | +3 |
| specific gravity | 2.70 (at 20 °C） |
| electron configuration | 1s22s22p63s23p1 |
| Common compounds | Aluminum oxide (Al₂O₃), aluminum chloride (AlCl₃), aluminum sulfate (Al₂(SO₄)₃), etc. |
| Content in the crust | Third (after oxygen and silicon) |
History of aluminum metal：
Aluminum has become one of the key engineering materials of our time. We find aluminum in the houses we live in, the cars we drive, the cell phones and computers we use every day, and in modern interior design. But 200 years ago, little was known about this metal.
In fact, the element aluminum was completely unknown two hundred years ago. It was the British physicist and chemist Sir Humphrey Davy who discovered the metallic element aluminum in an experiment. He was the first to use electrolysis to obtain a new chemical element: he obtained boron from boric acid. He went on to use electrolysis to isolate six other previously unknown metals: potassium, sodium, barium, calcium, magnesium and strontium. Davy proved the existence of aluminum, a metal found in aluminum oxide, and named it.
But an unexpected discovery from the lab didn’t stop mankind from exploring the aluminum metal. In the 19th century, the Danish physicist Christian Oster used electrolysis to obtain aluminum. Electrolysis or electrolytic reduction is also the process used today to produce aluminum.
How to get aluminum metal?
Extraction of aluminum metal is mainly achieved through a series of complex industrial processes, which include steps such as bauxite treatment, alumina production, and alumina electrolysis:
1. How is bauxite processed?
First, the bauxite ore needs to be crushed and milled to obtain fine powdered bauxite. This step is usually done mechanically using a jaw crusher or an impact crusher. Next, the milled bauxite is subjected to an acid leaching process. Acid leaching can be done using the sulfuric acid method. Sulfuric acid method is to react the milled bauxite with dilute sulfuric acid to obtain aluminum sulfate solution, which is filtered, stacked, pyrolyzed and finally obtained as alumina.
2. Electrolysis of alumina
Alumina is converted to aluminum by electrolytic reduction. This is currently the only method of industrial production of metallic aluminum. The electrolysis process takes place in an electrolytic cell, where the alumina is melted by the action of an electric current and pure aluminum is precipitated at the cathode. During electrolysis, oxygen is produced at the anode and aluminum is produced at the cathode.
Chemical equation for the electrolysis of aluminum oxide: 2Al₂O₃ (electrified) = 4Al + 3O₂↑
Characteristics of Metal Aluminum
Aluminum is a lightweight, corrosion-resistant, and thermally conductive metal element, and aluminum inherits these characteristics. Aluminum has the following characteristics:
1. Lightweight
Aluminum has a very low density of 2.7 g/cm³, about one-third the density of steel and copper. This lightweight property makes aluminum very popular in applications where weight reduction is required, such as in aerospace and construction. The use of aluminum can significantly reduce the weight of products, resulting in improved energy efficiency, reduced fuel consumption and lower emissions.
2. Corrosion resistance
Aluminum has good corrosion resistance in the natural environment. When aluminum is exposed to air, a dense film of aluminum oxide quickly forms on its surface, which prevents oxygen and moisture from further reacting with the aluminum, thus protecting the metal inside from corrosion.
3. Electrical and thermal conductivity
Aluminum is an excellent conductor of electricity and heat. Although its conductivity is slightly inferior to copper, but the conductivity of aluminum is still very high, and because of its low density, by weight, the conductivity of aluminum is even better than copper.
In addition, aluminum also has good thermal conductivity, which makes it an ideal material for manufacturing heat exchangers, heat sinks and other heat exchange equipment.
4. Wide range of processing
Aluminum is very processable, can be cast, forged, stamped, extruded and other processes into a variety of shapes and specifications of products. In addition, aluminum also has good ductility, can be made into aluminum sheet, aluminum profiles and other products. These characteristics make aluminum has a wide range of applications in the manufacturing industry.
5. Non-magnetic
Aluminum is a non-magnetic material, which means it is not affected by magnetic fields. This property is of great importance in the electrical and electronic industries, as a non-magnetic material avoids interference with electronic equipment and circuits.
6. Recyclability
Aluminum is highly recyclable, with low recycling costs and a simple recycling process. Recycled aluminum can be re-melted and made into new aluminum products with almost the same properties as virgin aluminum. Therefore, the recycling of aluminum is of great significance to save resources and protect the environment.
7. Stylish appearance
Aluminum metal has a silver-white luster and delicate texture, and can present a more beautiful appearance after appropriate surface treatment. This makes aluminum products have a wide range of application value in the field of building decoration, household goods and so on.
8. High strength and toughness
Although the strength of pure aluminum is relatively low, its strength and hardness can be significantly improved by alloying. For example, aluminum grades 6082 and 7075, their tensile strength can reach more than 600MPa.
In addition, metallic aluminum also has a certain degree of toughness and is able to resist impact and bending to a certain extent. This makes aluminum alloys widely used in structural materials, automotive parts and other fields.
Application of aluminum metal
Aluminum has a wide range of applications in many fields because of its light weight, corrosion resistance, good electrical conductivity and other characteristics, such as:
1. Transportation field:
- bumper beam
- Automobile frames
- Aircraft wings and structures
- Railroad tracks
- Traffic signals
- Bicycle frames
2. Construction field:
- Exterior Wall Decoration
- Aluminum ceilings and floors
- Handrails and partitions
- Door and window frames
- Roofing systems
- Railings and fences
3. Electronic uses:
Aluminum metal has a high coefficient of thermal conductivity and good thermal conductivity. Therefore, it is often used as a heat dissipation material for electronic devices to make heat sinks, heat sinks, and other thermal management devices.
Types of aluminum product in our lives:
1. aluminum plate: plate thickness between 0.15mm-2.0mm, a wide range of uses, such as the manufacture of computer shells, doors and windows.
2、Aluminum roll strip: used for winding transformers, inductors and motors, etc.
3, aluminum tubes: it can be used to manufacture seamless aluminum tubes, welded aluminum tubes and so on.
4, aluminum profiles: a wide range of aluminum profiles, mainly used in construction, industry and many other applications.
In conclusion
The discovery of aluminum metal, a major element of the earth’s crust, brought progress to human society. This is because the metal is lightweight, corrosion-resistant and flexible. So it is able to become our common cars, cell phones and building materials, etc.
For more detailed information about aluminum products, please click Hugh Aluminum —— a professional aluminum extrusion manufacturer, we provide excellent aluminum extrusions and aluminum profiles to you!
