Tellurium

Tellurium was isolated before it was known to be an element in its own right. Around 1782, Austrian mineralogist Franz Joseph Müller von Reichenstein examined an ore called Germanic gold. From this ore, he extracted a material that defied his analytical attempts and which he called Metallum problematikum. In 1798, Martin Heinrich Klaproth confirmed the elemental nature of the substance. He named the element after the human “celestial body” Tellus (Earth).

From the mid-19th century onwards, tellurium was used in metallurgy to refine steel and copper.

In the 1930s, tellurium was used in rubber vulcanization. In the 1950s, bismuth telluride was developed for use in thermoelectric cooling devices. In the 1960s, it began to be used in semiconductors and infrared detectors. In the 1980s, the first cadmium telluride (CdTe) solar cells were developed.

At the beginning of the millennium, the first CdTe thin-film solar cells were launched on the market.

Tellurium is mainly used in the production of cadmium telluride (CdTe) for thin-film solar cells. However, CdTe solar cells account for only five percent of the global photovoltaic market.

Another important area of application is the production of bismuth telluride (BiTe), which is used in thermoelectric devices for cooling and energy generation.
Metallurgical applications include its use as an alloying additive in steel to improve machining properties.

Anode slime from copper refining is the main source of tellurium, accounting for 90 percent of total production. China is the largest producer, with a 70 percent share of the global market, followed by Japan, Russia, and Sweden.

Within the EU, tellurium is mined as a by-product of gold extraction at the Kankberg mine in Sweden and refined at the nearby Rönnskär smelter owned by the Boliden Group.

Global annual production of tellurium amounts to between 900 and 1000 tons.

Several materials can replace tellurium in most applications, but usually with a loss of efficiency or product properties.
Amorphous silicon and copper indium gallium diselenide are the two main competitors to cadmium telluride in thin-film solar cells.
Bismuth selenide and organic polymers can replace BiTe in some thermoelectric components.
Bismuth, calcium, lead, phosphorus, selenium, and sulfur can replace tellurium in machine steel. Some of the chemical reactions catalyzed by tellurium can be carried out with other catalysts or by non-catalyzed processes.
In rubber compounds, sulfur or selenium can act as vulcanizing agents instead of tellurium.
The selenides and sulfides of niobium and tantalum can serve as electrically conductive solid lubricants instead of the tellurides of these metals.