Aluminium facts for kids
Aluminium (American spelling: aluminum) is a chemical element. The symbol for aluminum is Al, and its atomic number is 13. Aluminum is the most abundant metal on earth. It is known for its ability to resist corrosion and its light weight. Aluminum and its alloys are used in many industries (like transportation, aerospace, and building industries) to manufacture a large variety of products and is very important to the world economy.
Sometimes there can be disagreement about who discovered something, even when all the facts are known. Friedrich Wöhler is credited with isolating aluminum in 1827. The metal, however, had been produced for the first time two years earlier — but in an impure form — by the Danish physicist and chemist Hans Christian Ørsted. Therefore, Ørsted can also be listed as the discoverer of aluminum.
Contents
Properties
Aluminum is a very good conductor of electricity and heat. It is light and strong. It can be hammered into sheets (malleable) or pulled out into wires (ductile). It is a highly reactive metal, although it is corrosion resistant.
Aluminum prevents corrosion by forming a small, thin layer of aluminum oxide on its surface. This layer protects the metal by preventing oxygen from reaching it. Corrosion can not occur without oxygen. Because of this thin layer, the reactivity of aluminum is not seen.
Where it occurs
Aluminum is the most abundant metal in the Earth's crust, and the third-most abundant element overall, after oxygen and silicon. But it is not found free in nature. Although aluminum is a common and widespread element, not all aluminum minerals are economically good sources of the metal.
Almost all metallic aluminum is produced from the ore bauxite. Bauxite occurs as a weathering product of low iron and silica bedrock in tropical climatic conditions. In 2017, most bauxite was mined in Australia, China, Guinea, and India.
Aluminum production is highly energy-consuming, and so the producers tend to locate smelters in places where electric power is both plentiful and inexpensive. As of 2012, the world's largest smelters of aluminum are located in China, Russia, Bahrain, United Arab Emirates, and South Africa.
Aluminum was once considered a precious metal that was even more valuable than gold. This is no longer true because, as technology improved, it became cheaper and easier to make pure metal.
Uses
Many things are made of aluminum. Much of it is used in overhead power lines. It is also widely used in window frames and aircraft bodies. It is found in homes in saucepans, soft drink cans, and cooking foil. Aluminum is also used to coat car headlamps and compact discs.
Pure aluminum is very soft, so a harder metal is almost always added to it. The harder metal is usually copper. Copper/aluminum alloys are used to make ships because the aluminum prevents corrosion and the copper prevents barnacles.
Aluminum compounds are used in deodorants, water processing plants, food additives, and antacids. Aluminum helps us get from place to place since it's a part of cars, trucks, airplanes, bicycles, rockets, and more.
Aluminum is the most widely used non-ferrous metal. The global production of aluminum in 2016 was 58.8 million metric tons. It exceeded that of any other metal except iron (1,231 million metric tons).
When aluminum is combined with Fe2O3 (Ferric Oxide, or rust) in the right quantity, thermite can be made. Thermite burns very quickly and with extreme heat. Aluminum is one of the primary components of the fuel that propels rockets into space.
Toxicity
In most people, aluminum is not as toxic as heavy metals. Aluminum is classified as a non-carcinogen by the United States Department of Health and Human Services. However, some studies have shown that aluminum can cause neurological diseases that involve inflammatory neurodegeneration, the inability to behave properly, and mental decline. Excessive consumption of antacids, antiperspirants, vaccines, and cosmetics provide serious exposure levels.
The metal is protected by a surface layer of aluminum oxide. This surface layer forms at once when the metal is exposed to air and is very stable. So dishes, pots, and pans can be made of aluminum, and aluminum foil can be used for packing sensitive foods. However, acidic foods, such as tomatoes, can dissolve the surface oxide layer and some of the aluminum underneath. This isn't dangerous and doesn't affect the strength of the aluminum object, but can lead to off tastes in the food, which is why it is usually not recommended to cook acidic foods in aluminum cookware.
Exposure to powdered aluminum or aluminum welding fumes can cause pulmonary fibrosis. Fine aluminum powder can ignite or explode, posing another workplace hazard.
Did You Know?
- Recycling aluminum requires one twentieth as much energy as producing aluminum from raw ore.
- Aluminum is the most common metal in the earth's crust.
- Aluminum and Aluminium are two different names for this metal.
Recycling
Recovery of the metal through recycling has become an important task of the aluminum industry. Recycling was not well-known or used until the late 1960s, when the growing use of aluminum beverage cans brought it to public awareness.
Since aluminum needs to be made by electrolysis, it requires a very large amount of electrical power. Recycling aluminum would be much cheaper. The cost of recycling aluminum is much less than the cost of making it from bauxite.
Interesting facts about aluminum
- The Earth’s crust is made of about 8.2% aluminum, but it must be processed first to separate it from other chemical compounds and minerals.
- Aluminum weighs one-third less than steel.
- Aluminum does not rust because it does not contain iron.
- Aluminum was documented as being used in ancient Greece.
- Napoleon III served meals on aluminum plates because at the time, it was considered more valuable than silver (or gold).
- A new aluminum can is able to be made as little as 60 days after the recycling of other aluminum cans.
- Because of recycling, about 75% of all aluminum that has ever been made is still being used today.
- Aluminum has been found on the moon.
Related pages
Images for kids
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High-resolution STEM-HAADF micrograph of Al atoms viewed along the [001] zone axis.
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Aluminium hydrolysis as a function of pH. Coordinated water molecules are omitted. (Data from Baes and Mesmer)
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Structure of trimethylaluminium, a compound that features five-coordinate carbon.
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Bauxite, a major aluminium ore. The red-brown color is due to the presence of iron oxide minerals.
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Friedrich Wöhler, the chemist who first thoroughly described metallic elemental aluminium
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The statue of Anteros in Piccadilly Circus, London, was made in 1893 and is one of the first statues cast in aluminium.
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1897 American advertisement featuring the aluminum spelling
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Extrusion billets of aluminium
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Common bins for recyclable waste along with a bin for unrecyclable waste. The bin with a yellow top is labeled "aluminum". Rhodes, Greece.
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Aluminium-bodied Austin A40 Sports (c. 1951)
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Aluminium can
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Laser deposition of alumina on a substrate
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Schematic of aluminium absorption by human skin.
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There are five major aluminium forms absorbed by human body: the free solvated trivalent cation (Al3+(aq)); low-molecular-weight, neutral, soluble complexes (LMW-Al0(aq)); high-molecular-weight, neutral, soluble complexes (HMW-Al0(aq)); low-molecular-weight, charged, soluble complexes (LMW-Al(L)n+/−(aq)); nano and micro-particulates (Al(L)n(s)). They are transported across cell membranes or cell epi-/endothelia through five major routes: (1) paracellular; (2) transcellular; (3) active transport; (4) channels; (5) adsorptive or receptor-mediated endocytosis.
See also
In Spanish: Aluminio para niños
