The history of aluminium use:
Aluminium is now one of the most widely used metals, but it is also one of the hardest to refine due to its reactivity with other elements. Even as late as the turn of the century, aluminium was considered very valuable and expensive, even more so than gold. In some cultures, only the most honored guests would be given aluminium cutlery at functions held by wealthy people, while others had to make do with gold or silver cutlery.
A description of the aluminium ore, including a list of its contents:
Pure aluminium oxide is known as alumina (Al2O3). It is found as corundum, a crystalline form. Aluminium can also occur as cryolite (Na3AlF6).
Traces of other metal oxides in aluminium oxide tint it, forming stones, often precious. For example, chromium gives rubies a red colour, and cobalt makes sapphires blue.
Aluminium, like many other metals, is not found in its pure form but is associated with other elements in rocks and minerals. An aluminosilicate such as feldspar (KAlSi3O8) is the main constituent of many rocks, such as granite, which is quartz and mica cemented together with feldspar. These rocks are gradually weathered and broken down by the action of carbon dioxide from the air dissolved in rainwater, forming kaolin. This is further broken down to form other substances, ultimately resulting in the formation of aluminium deposits.
Where and how is aluminium mined? Aluminium is never found in its pure state until it has been refined. Aluminium is made by refining alumina, which is found from the ore bauxite. Bauxite is often mined using the opencast method. Aluminium deposits are found in many countries, but the countries with significant deposits include Guinea, Jamaica, Surinam, Australia, and Russia. How is aluminium refined? One method is the electrolytic process, which is performed when a low voltage current is passed through a bath containing molten alumina.
The alumina is broken down into aluminum metal, which collects at the bottom of the bath at one electrical pole, the cathode, and the oxygen, which reacts at the other pole, the anode, to give carbon dioxide and some carbon monoxide. Aluminum is now the second most widely used metal after iron. Aluminum and its alloys, such as duralumin, are used as structural metals for a wide variety of products, from aircraft to cooking utensils. Aluminum foil is used to wrap food and is also being used to replace copper wire in electrical windings. Aluminum mirrors are used in some large astronomical telescopes. Some aluminum ores are found in the form of gems and precious stones.
Aluminium is also used in the making of vehicles, such as aircraft, due to its strength and light weight. However, it is not used as much in cars due to its cost. Category: Social Issues.
