aluminium
Aluminium is the most abundant metal in the world; however it can be quite expensive due to the extraction method, electrolysis. Aluminium ore is called bauxite, it is then purified into a white powder (aluminium oxide) then the aluminium can be extracted.
To turn it into aluminium they heat the powder till it’s molten so electricity can pass through it. Its melting point is over 2,000 Celsius, so it would therefore be quite expensive. One way of cutting costs is by dissolving it in molten cryolite. Which has a lower melting point.
Current price £1.53 for a kilo of aluminium.
Iron is the second most common metal in the world and cheaper to extract than aluminium. It is extracted by using a blast furnace. Iron ores such as haematite contain iron oxide, the oxygen must be removed which then leaves the iron behind. This reaction is called a reduction reaction.
Carbon is more reactiuve than iron so it can displace the iron and join with the oxide
2Fe2O3 + 3C → 4Fe + 3CO2
Above you can see the iron oxide has been separated into iron and carbon dioxide.
Current price £1.03 for a kilo of iron ore.
Gold extraction or recovery from its ores may require a combination of comminution, mineral processing, hydrometallurgical, and pyro-metallurgical processes to be performed on the ore. Gold is not hard to extract as it is found as elements. However finding it is quite hard as it is found in very deep gold mines and not a lot of it is found within quite a large area of rock.
The cheapest way of extract gold is cyanide leeching. Cyanide is used to leech out the gold particles, which can even leak into water and streams. Current price £35,000 for a kilo of gold.
Economic reasons
Aluminium
Can be found in many places
Already a lot of business
Quite expensive to extract
Iron
Blast furnace always has to be on
If there is a power cut all iron in the furnace is wasted
To turn it into aluminium they heat the powder till it’s molten so electricity can pass through it. Its melting point is over 2,000 Celsius, so it would therefore be quite expensive. One way of cutting costs is by dissolving it in molten cryolite. Which has a lower melting point.
Current price £1.53 for a kilo of aluminium.
Iron is the second most common metal in the world and cheaper to extract than aluminium. It is extracted by using a blast furnace. Iron ores such as haematite contain iron oxide, the oxygen must be removed which then leaves the iron behind. This reaction is called a reduction reaction.
Carbon is more reactiuve than iron so it can displace the iron and join with the oxide
2Fe2O3 + 3C → 4Fe + 3CO2
Above you can see the iron oxide has been separated into iron and carbon dioxide.
Current price £1.03 for a kilo of iron ore.
Gold extraction or recovery from its ores may require a combination of comminution, mineral processing, hydrometallurgical, and pyro-metallurgical processes to be performed on the ore. Gold is not hard to extract as it is found as elements. However finding it is quite hard as it is found in very deep gold mines and not a lot of it is found within quite a large area of rock.
The cheapest way of extract gold is cyanide leeching. Cyanide is used to leech out the gold particles, which can even leak into water and streams. Current price £35,000 for a kilo of gold.
Economic reasons
Aluminium
Can be found in many places
Already a lot of business
Quite expensive to extract
Iron
Blast furnace always has to be on
If there is a power cut all iron in the furnace is wasted