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c6 (purification of copper (easily extracted by reduction with carbon, ore…
c6
purification of copper
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copper produced this way is impure, so it doesn't conduct electricity well
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electrolysis purifies it, producing pure copper, a much better conductor
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biological extraction
supply of metal rich ores eg copper ore is limited, but demand for lots of metals is growing, may lead to shortages in the future
bioleaching : uses bacteria to separate metal from their ores, eg copper can be separated from copper sulfide this way
bacteria get energy from bonds between atoms in the ore, separating out the metal from the ore
the leachate (solution made in the process) contains metal ions, can be extracted by electrolysis or displacement with a more reactive metal
phytoextraction : growing plants in soil that contains metal compounds, plants can't use or get rid of the metals so gradually build up in the leaves
plants can be harvested, dried and burned in a furnace, ash contains metal compounds which from which the meta can be extracted by electrolysis or displacement reactions
traditional mining are damaging to environment, these have smaller impact but are slow
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solder
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unlike pure materials, no definite melting point, gradually solidifies as it cools
useful for joining metal things together as easily worked, eg connecting components in electronic circuits
low melting point, can melt solder without deforming other components in the circuit
metal ores
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the main aluminium ore is bauxite, aluminium oxide
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steel
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harder than iron, stronger than iron as long as the amount of carbon is not greater than 1%
iron on its own will rust quickly, steel less likely to rust, bridges, cutlery, engine parts, saucepans all made of steel
brass
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most properties are a mixture of those of copper and zinc, brass is harder than both
used for making bass instruments like trumpets, as for fixtures and fittings like screws and doorknobs
bronze
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harder and stronger than tin, more resistant to corrosion than both
used to make springs, motor bearings, bells and sculptures
duralumin
94% aluminium, 4% copper, 1% magnesium and small amounts of manganese
low density, very light, much stronger than aluminium
strong and light, good for making parts of aeroplanes