Aug 7 2013
Topics Covered
Introduction
Chemical Properties
Physical Properties
Mechanical Properties
Thermal Properties
Applications
Introduction
Tellurium is a chemical element with Te as its symbol. It belongs to group 16, periodic number 5 of the periodic table. Its atomic number is 52.
Tellurium is a silvery-white semi-metallic element that is crystalline and brittle. It remains stable in water or hydrochloric acid, but will dissolve in nitric acid. It is a semiconductor and is often doped with tin, gold, silver, or copper.
Tellurium is obtained from the ores calaverite, krennerite, and sylvanite. It can also be obtained as a byproduct of mining and refining copper. It is produced mainly in USA, Canada, Japan, and Peru.
Chemical Properties
The chemical properties of tellurium are provided in the table below.
|
Chemical Data |
|
CAS number |
13494-80-9 |
|
Thermal neutron cross section |
4.7 barns/atom |
|
Ionic radius |
0.560 Å |
|
Electronegativity |
2.1 |
|
X-ray absorption edge |
0.38972 Å |
|
Electrochemical equivalent |
0.99 g/A/h |
Physical Properties
The following table discusses the physical properties of tellurium.
|
Properties |
Metric |
Imperial |
|
Density |
6.23 g/cm3 |
0.225 lb/in3 |
|
Melting point |
450°C |
842°F |
|
Boiling point |
1390°C |
2534°F |
Mechanical Properties
The mechanical properties of tellurium are tabulated below.
|
Properties |
Metric |
Imperial |
|
Tensile strength |
11MPa |
1600 psi |
|
Poisson’s ratio |
0.33 |
0.33 |
|
Modulus of elasticity |
40 GPa |
5800 ksi |
|
Shear modulus |
15.16 GPa |
2199 ksi |
|
Hardness, Brinell |
25 |
25 |
Thermal Properties
The thermal properties of tellurium are tabulated below.
|
Properties |
Metric |
Imperial |
|
Thermal expansion co-efficient (@20-100°C/68-212°F) |
16.8 µm/m°C |
9.33 µin/in°F |
|
Thermal conductivity |
1.97 W/mK |
13.7 BTU in/hr.ft².°F |
Applications
The following are the application areas of tellurium:
-
As an additive to steel
-
Alloyed to copper, aluminum, lead or tin
-
As an additive to lead to enhance its strength, durability, and resistance to corrosion
-
For ceramics, blasting caps, cast iron, solar panels, and chalcogenide glasses
-
As an additive to rubber to speed up the curing process, reduce the susceptibility of the rubber to ageing, and to increase its resistance to oil.