Geology Reference
In-Depth Information
B.2.69 Tin
Tin is a silvery-white metal. There are a few tin-containing minerals but only one
is of commercial significance and that is cassiterite SnO
2
.
It finds extensive use as a protective layer for mild steel. Alloys of tin are used
in many ways, such as in solder for the joining of pipes or electronic circuits, bell
and babbit metal and dental amalgams. The principal alloys of tin are bronzite
(tin and copper), soft solder (tin and lead), pewter (75% tin and 25% lead) and
britannia metal (tin with small amounts of antimony and copper).
B.2.70 Titanium
Titanium is a light, strong transition metal, well known for its corrosion resistance
and high strength-to-weight ratio. It is an abundant element on Earth and is found
in minerals rutile TiO
2
, brookite TiO
2
, anatase TiO
2
, illmenite Fe
2+
TiO
3
, leu-
coxene CaTiSiO
5
and titanite CaTiSiO
5
. The chiefly mined ore is ilmenite but
leucoxene and rutile are also important.
Titanium is predominantely consumed in the form of titanium dioxide TiO
2
, a
white pigment in paints, paper and plastics. Titanium alloys are used in aircraft,
pipes for power plants, armour plating, naval ships and missiles. In medicine,
titanium is used to make hip and knee replacements, pace-makers, bone-plates and
screws.
B.2.71 Uranium
Uranium is a silvery metallic radioactive element of the actinide group. It is
widely distributed and the most important ores are uraninite UO
2
and carnotite
K
2
(UO
2
)
2
(V O
4
)
2
3H
2
O. However, even these are usually dispersed so that typi-
cal ores contain only about 0.1% with many of the more readily exploited deposits
nearing exhaustion. Significant concentrations of uranium occur in monazite sands
or lignite.
Uranium gained importance with the development of practical uses of nuclear
energy. Depleted uranium is used as shielding to protect tanks and also in bullets
and missiles. However, the main use of uranium is to fuel commercial nuclear power
plants.
B.2.72 Vanadium
Vanadium is a transition metal, widely, though sparsely distributed. The most
important vanadium minerals are patronite V S
4
, vanadinite Pb
5
(V O
4
)
3
Cl and
carnotite K
2
(UO
2
)
2
(V O
4
)
2
3(H
2
O). Vanadium is also found in some crude oils,
coals, oil shales and tar sands. Although more than 60 different minerals of vana-
dium have been characterised, there are few concentrated deposits and most of it is
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