Tin on Earth
Tin, element 50 named Sn
| ||Automatic translation|| |
Category: Chemical elements
The element 50, tin is a rare metal, it is only 0.004% of Earth's crust. World production is around 220,000 tons per year, extract, mainly minerals of stannite and cassiterite. The ore producing countries are China, Indonesia, Russia, Malaysia, Peru, Brazil, Bolivia and Mexico. The tin has a name of Latin origin 'or Stannum Stagnum'. It was first used by mixing it with silver and lead. To get the tin, the Phoenician ships crossed the Pillars of Hercules (the name given in Roman times, the mountains bordering the Strait of Gibraltar. This is all just the Rock of Gibraltar). They went to Brittany and Cornwall, assumed to be the mythical "islands Cassiterides" in search of tin mines.
Julius Caesar described the exploitation of tin minerals in the mines of Cornwall in Britain.
The road of tin, was in Gaul and borrowed the Rhone, during the conquest of Gaul by Julius Caesar.
Depending on the temperature, tin is transformed.
The change in density that accompanies this transformation affects the mechanical cohesion of the metal. Below -50 ° C, the transformation of the tin is accelerating and it breaks down into dust. This phenomenon is called "tin plague".
|Features of tin|| |
| || |
|Color ||silver gray|
|Atomic mass||118,710 u|
|Mass heat||228 J/(kg/K)|
|Electron by energy level||2, 8, 18, 18, 4|
|Melting point||505 K|
|Boiling point||2 875 K|
|The most frequent isotopes||116Sn 14,54 % |
118Sn 24,23 %
120Sn 32,59 %
|Electrical conductivity||9,17 106 S/m|
|Thermal conductivity||66,6 W/(m/K)|| |
Image: Tin is produced in the supernova, as all heavy chemical elements found on Earth. Its dust end up in the nebulae, then solar systems.
Cassiterite and stannite
| || || || |
Cassiterite (Greek kassiteros, tin) is an oxide (SnO2).
This is the main mineral of tin mines.
Cassiterite crystals consist of short reddish-brown and black. It is unalterable. It is found in igneous rocks.
In ancient times, around 4000 years, blacksmiths knew that by heating malachite they obtained, by reduction, copper red, while a heated mixture of malachite and cassiterite led to bronze, brown.
Bronze is a mixture of copper and tin. It seems that the bronze is the alloy first made and used by man.
Besides his influence was so great that a period of prehistoric bears its name, "Bronze Age".
This period lasts from about 2 000 to 800 BC). However, at Ur in Mesopotamia, have been found bronze objects dating from 5000 years BC.
Stannite is the common tin sulfide.
Stannite has a brightness and color steel, it has a granular form.
These assemblies of small crystals of about 30 mm, often associated with different minerals of copper, arsenic and tungsten.
This is a tin ore.
World reserves of tin are mainly in Malaysia, where it operates cassiterite by dredging seabed, to the detriment of the environment.
| || |
Image: Cassiterite is a mineral composed of tin dioxide SnO2 formula, possibly containing traces of iron, tantalum, niobium, zinc, tungsten, manganese, scandium, germanium, indium and gallium.
| || |
Image: Stannite is a mineral composed of copper sulfide, iron and tin of formula Cu2FeSnS4, may contain traces of silver, zinc, germanium, indium and cadmium.