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C1 Metals and Their Uses
A rock containing enough metal to make extraction economically viable/achievable.
Has low resistance, allowing an electrical current/thermal energy to pass through it easily.
The removal of oxygen from a compound. Also can refer to when electrons are added to an element/compound.
When a metal can be hammered, or pressed into a shape without breaking.
When a metal can be drawn into wires.
Methods of Extraction
Metals are found within the Earth's crust. They need to be extracted before they can be used.
The least reactive metals can be found natively as they are unreactive.
These elements are found between Group 2 and 3 on the Periodic Table. Most of the elements on the table are metals, and most metals are transition metals.
They all share some common properties that mean they are: good conductors of heat and electricity, malleable, ductile, shiny, sonorous and strong.
Iron is extracted using a blast furnace. The most common ore of iron is iron(III) oxide, also known as haematite. The ore is reduced, using carbon, to produce iron.
iron oxide + carbon --> iron + carbon dioxide
In a blast furnace, it is so hot that carbon monoxide can also cause reduction:
iron oxide + carbon monoxide --> iron + carbon dioxide
Copper isn't very reactive, but is reactive enough to be found in ores. These compounds have a high concentration of copper which can be extracted by smelting. It is then purified by electrolysis.
One copper ore is called chalcocite, and contains copper(I) sulfide. It can be thermally decomposed to produce copper, but also makes sulfur dioxide (causes acid rain).
Some plants take up copper compounds through their roots, and a large concentration of copper can build up in the plant. These plants can be burned to extract the copper.
Some bacteria absorb copper compounds. A similar process to above can be completed, to extract the copper.
Because iron is more reactive than copper, iron can be used to displace copper from copper(II) sulfate.
Aluminium & Titanium
These metals are both strong, but an added bonus is they are less dense than other metals. They are also resistant to corrosion, making these metals very useful.
Aluminium is extracted by electrolysis as it's more reactive than carbon, so cannot be displaced. Electrolysis is very expensive as we need high temperatures to melt the metal compound.
Titanium could be extracted using carbon, if it did not react with it to make a brittle compound. Sodium/magnesium are used to extract instead, but these must be extracted using electrolysis first.
Iron and Steel
Pure iron is soft and malleable, as its atoms have a regular layer arrangement. These layers can easily slide over each other, and makes pure iron too soft for many uses.
Iron from a blast furnace contains about 4% carbon, and it is too brittle for most uses. This 'pig iron' is then turned into steel by removing some carbon. The carbon is removed from molten 'pig iron' by blowing oxygen through it, making carbon monoxide and carbon dioxide. Other metals can be added to make alloys with specific uses:
Low carbon steel - easily shaped - used for car body panels
High carbon steel - quite hard - used for cutting tools
Stainless steel - resistant to corrosion (chromium-nickel) - used for cutlery
When a metal is mixed with other element(s) they form an alloy. Alloys have different sized atoms, which means the layers are distorted. They cannot easily slide over each other, and so make a harder material than the pure metal.
Bronze (copper and tin) is tough and resistant to corrosion. Brass (copper and copper and zinc) much harder than copper, and can be hammered into shapes.
Duralumin (aluminium, copper, and other metals) is used in aircrafts.
18 carat gold (75% gold, 25% copper and other metals) is used for jewellery.
Page last updated: 16/04/2017