Tellurium is a heavy, brittle, rare metalloid of silver-white colour. Its boiling point is 988°C and melting point is 449.51°C. Tellurium is one of the rarest elements found in the Earth’s crust. It occurs in relatively few minerals including tellurite, sylvanite and calaverite. Tellurium is a by-product from the production of metals, most frequently cooper. The element is mildly toxic; ingestion can cause drowsiness or problems with the central nervous system and digestive tract.
Tellurium is used for various needs. The element’s key application is the production of iron and steel alloys, accounting for around 50% of the annual production volume of tellurium. In such alloys tellurium is used to increase machineability. It can also be alloyed with copper and lead. Tellurium acts as a light-sensitive semiconductor in solar cell technology: it enhances the effectiveness of power generation. The metalloid finds application in the production of diverse products including chalcogenide and tinting glasses, ceramics, blasting caps and initiators (required in radical polymerization reactions), thermoelectric apparatuses. Tellurium is used as a vulcanizing agent and accelerator in the production of rubber, as a catalyst in oil refining and synthetic fibre production, and also as a gasoline additive reducing engine knocks in automobiles.
End-uses of tellurium
In 2012, the world deposits of tellurium contained in copper reserves were estimated at around 24,000 tonnes. The USA, Peru and Canada possess the most substantial tellurium reserves. Smaller reserves are found in China, Russia, Australia, Germany and Belgium.
In 2012, the global tellurium production declined by nearly 2.3% and went down to 125 tonnes. The USA is the world dominant producer of tellurium, accounting for over 30% of the overall production volume.
Tellurium: structure of the global production by country, 2012
The world production of tellurium is poised to witness steady growth and climb to almost 135 tonnes in 2015, driven by the growing demand for the product from various application areas.
More information on the tellurium market can be found in the report Tellurium Market Review.