Extracting iron and copper
Ores
A substance is unreactive or inert if it does not easily take part in chemical reactions.Shiny element that is a good conductor of electricity and heat, and which forms basic oxides., such as gold, are found in the Earthâs The outer layer of the Earth on top of the mantle. as the uncombined A substance made of one type of atom only.. However, most metals are found combined with other elements to form A substance formed by the chemical union of two or more elements..
An A rock containing enough quantities of a mineral for extraction to be possible. is a rock that contains enough of a metal or a metal compound to make extracting the metal worthwhile:
- low grade ores contain a small percentage of the metal or its compound
- high grade ores contain a larger percentage
Most metals are extracted from ores found in the Earthâs crust. It is more expensive and wasteful to extract a metal from a low grade ore, but a lot of the high grade ores have already been used.
Extraction methods
The The process of obtaining a metal from a mineral, usually by reduction or electrolysis. method used depends upon the metal's position in the A list of elements in order of their reactivity, usually from most reactive to least reactive.. In principle, any metal could be extracted from its compounds using The decomposition (breakdown) of a compound using an electric current.. However, large amounts of Energy transferred by electricity. are needed to do this, so electrolysis is expensive.
If a metal is less The tendency of a substance to undergo a chemical reaction. than carbon, it can be extracted from its compounds by heating with carbon. Copper is an example of this. Copper mostly occurs as sulfide ores, which are heated in air to convert them to copper oxide. A term used to describe a liquid substance (eg rock, glass or metal) formed by heating a solid. copper can be produced from copper oxide by heating with carbon:
copper oxide + carbon â copper + carbon dioxide
2CuO(s) + C(s) â 2Cu(l) + CO2(g)
Copper oxide is A substance is reduced if it loses oxygen or gains electrons. as carbon is Chemical substances are oxidised by the addition of oxygen, removal of hydrogen or the removal of electrons., so this is an example of a When reduction and oxidation take place at the same time.. The impure copper is purified by electrolysis.
The table summarises the extraction methods used for different metals.
Although an unreactive metal is found as the uncombined element, chemical reactions are often needed to remove other elements that might contaminate it.
Extracting iron
Iron is extracted from iron ore in a large container called a blast furnace. Iron(III) oxide is reduced to molten iron when it reacts with carbon. For example:
iron(III) oxide + carbon â iron + carbon monoxide
Fe2O3(s) + 3C(s) â 2Fe(l) + 3CO(g)
In the high temperatures of a blast furnace, carbon monoxide also reduces iron(III) oxide:
iron(III) oxide + carbon monoxide â iron + carbon dioxide
Fe2O3(s) + 3CO(s) â 2Fe(l) + 3CO2(g)
This method of extraction works because carbon is more reactive than iron, so it can Take the place of another substance in a chemical reaction. For example, a metal can displace a less reactive metal from its oxide, removing oxide ions from the less reactive metal and becoming an oxide itself. iron from iron compounds.
Extracting a metal by heating with carbon is cheaper than using electrolysis.
Question
Write a balanced equation for the reaction between iron(III) oxide and carbon, forming molten iron and carbon dioxide.
2Fe2O3(s) + 3C(s) â 4Fe(l) + 3CO2(g)