Traces of othermetal oxides in Aluminium oxide tint it to make it form stones (often precious)for example: chronium gives a red colour to rubies, and cobalt makes the blue insapphires. How Aluminium deposits are formedAluminium (like many other metals) is not found in it’s pure form, butassociated with other elements in rocks and minerals. An aluminosilicate such asfelspar (KAlSi3O8) is the main constituent of many rocks such as granite, whichis quartz and mica cemented together with felspar. These rocks are graduallyweathered and broken down by the action of carbon-dioxide from the air dissolvedin rainwater forming kaolin’. This is further broken down to form othersubstances, ultimately resulting in the formation of Aluminium deposits.
Where and how Aluminium is mined?Aluminium is never found in it’s pure state until it has been refined. Aluminiumis made when refining alumina, which is in turn found from the ore bauxite’. Bauxite is often mined in the opencast method. Aluminium deposits are found in many countries, but the countries withsignificant deposits include: Guinea, Jamaica, Surinam, Australia and Russia. How is Aluminium refined?One method is the electrolytic process’. This is performed when a low voltagecurrent is passes through a bath containing alumina in the molten form.
Thealumina is broken down into Aluminium metal which collects at the bottom of thebath at one electrical pole, the cathode, and the oxygen which reacts at theother pole, the anode, to give carbon-dioxide and some carbon-monoxide. The uses and properties of AluminiumAluminium is now the second most widely used metal, after iron. Aluminium andit’s alloys, such as duralumin’, are used as structural metals for a widevariety of products from aircraft to cooking utensils. Aluminium foil is used towrap food and is also being used to replace copper wire in electrical windings. Aluminium mirrors are used in some large astronomical telescopes. Some Aluminiumores are found in the form of gems and precious stones.
Aluminium is also usedin the making of vehicles such as aircraft due to it’s strength and light weight,but is not used so much in cars due to it’s cost.Category: Social Issues