1.1 Ores are naturally occurring rocks that provide a
starting point for the manufacture of metals.
1.1.1 A metal ore is a rock containing a
metal, or a metal compound, in high
enough concentration to make it
economic to extract the metal.
126.96.36.199 Ores are mined and may need to be concentrated
before the metal is extracted and purified.
188.8.131.52.1 The economics of extraction may change over time;
as a metal becomes rarer, an ore may be used when
it was previously considered too expensive to mine.
184.108.40.206.1.1 Unreactive metals are found as the
native metal but most metals are found
as compounds; requiring chemical
reactions to extract the metal.
220.127.116.11.1.1.1 Metals less reactive than carbon
can be extracted from their
oxides by reduction with carbon.
18.104.22.168.22.214.171.124 Metals more reactive than carbon are extracted
by electrolysis, an expensive process due to the
many stages and the energy required.
126.96.36.199.188.8.131.52.1 Copper can be extracted from copper-rich
ores by smelting, then purified by electrolysis.
The supply of copper-rich ores is limited.
184.108.40.206.220.127.116.11.1.1 There are ways to limit the environmental
impact of traditional mining.
18.104.22.168.22.214.171.124.1.1.1 Phytomining is the process
of burning plants which
have absorbed metal
compounds to produce
ash. Bioleaching uses
bacteria to produce
leachate solutions that
contain metal compounds.
126.96.36.199.188.8.131.52.184.108.40.206 Aluminium is extensively recycled
because less energy is needed than
to extract aluminium from its ore;
preserving limited resources and
energy, causing less damage to the
2 C1.3.2 Alloys
2.1 Iron from the blast furnace contains about
96% iron; the impurities make it brittle.
2.1.1 Most iron is converted
into steels; alloys
which are mixtures of
iron and carbon.
220.127.116.11 Alloys can be designed for
specific uses. Low-carbon
steels are easily shaped,
high-carbon steels are hard,
and stainless steels are
resistant to corrosion.
18.104.22.168.1 Most metals in
everyday use are
alloys as pure
copper, gold, iron
are too soft for
3 C1.3.3 Properties And Uses Of Metals
3.1 Transition metals, like other metals, are good
conductors and can be bent or hammered into
shape. They are useful as structural materials.
3.1.1 Copper has properties making it useful for electrical
wiring and plumbing: good conductor of electricity and
heat; can be bent but is hard enough to be used to
make pipes or tanks and does not react with water.
22.214.171.124 Low density and resistance to corrosion
make aluminium and titanium useful metals.