 Discovery Information
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| Who: Franz Muller von Reichenstein |
| When: 1782 |
| Where: Romania |
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| Name Origin
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| Greek: tellus (the Earth). |
| "Tellurium" in different languages. |
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| Sources
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| Obtained as a by-product of copper and lead refining. Also found in the mineral calaverite (AuTe2). Most tellurium is produced in the USA, Canada, Peru and Japan. Annual production is around 220 tons.
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| Abundance
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| Universe: 0.009 ppm (by weight) |
| Carbonaceous meteorite: 2.1 ppm |
| Earth's Crust: 0.001 ppm |
| Seawater: |
| Atlantic surface: 1.6 x 10-7 ppm
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| Atlantic deep: 7 x 10-8 ppm
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| Pacific surface: 1.9 x 10-7 ppm
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| Pacific deep: 1.7 x 10-7 ppm
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| Uses
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| Used to improve the machining quality of metal products and to colour glass and ceramics. Also used in thermoelectric devices
(bismuth telluride (Bi2Te3)), vulcanization of rubber, percussion caps, battery plate protectors and electrical resistors.
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| It is added to lead to improve its strength and durability, and to decrease the corrosive action of sulfuric acid (H2SO4). When added to stainless steel and copper it makes these metals more workable. It is alloyed into cast iron for chill control.
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| When alloyed with both cadmium and mercury, to form mercury cadmium telluride, an infrared sensitive semiconductor material is formed.
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| Tellurium is being used (as GeSbTe, an alloy of germanium, antimony and tellurium) in the new phase change memory chips developed by Intel.
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| Cadmium telluride (CdTe) is used in solar panels. NREL lab tests using this material achieved some of the highest efficiencies
for solar cell electric power generation.
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| History
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| Tellurium (Latin tellus meaning "earth") was discovered in 1782 by the Hungarian Franz-Joseph Muller von Reichenstein (Muller Ferenc) in Nagyszeben (now, Sibiu) Transylvania. In 1789, another Hungarian scientist, Pal Kitaibel, also discovered
the element independently, but later he gave the credit to Muller. In 1798, it was named by Martin Heinrich Klaproth who earlier isolated it.
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| Tellurium was used as a chemical bonder in the making of the outer shell of the first atom bomb. The 1960s brought growth
in thermoelectric applications for tellurium, as well as its use in free-machining steel, which became the dominant use.
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| Notes
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| It is chemically related to selenium and sulfur, the conductivity of this element increases slightly when exposed to light. It can be doped with copper, gold, silver, tin, or other metals. Tellurium gives a greenish-blue flame when burned in normal air and forms tellurium dioxide as a result.
When in its molten state, tellurium is corrosive to copper, iron, and stainless steel.
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| 128Te has the longest known half-life, 2.2 x 1024 years, among all radioactive isotopes.
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| Hazards
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| Humans exposed to as little as 0.01 mg/m3 or less in air develop "tellurium breath", which has a garlic-like odour. The garlic odour that is associated with human
intake of tellurium compounds is caused from the tellurium being metabolized by the body. When the body metabolizes tellurium in any oxidation state, the
tellurium gets converted into dimethyl telluride, which is volatile and produces the garlic-like smell.
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| Tellurium and tellurium compounds should be considered to be toxic and need to be handled with care.
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