Sunday, August 28, 2011

Rare Earths Guest Post: Tellurium, is There Enough?

Tellurium pic.JPGIn 2004 you could purchase tellurium for $10 per kg. Then the solar industry came along and disrupted the market. In August 2011 the price is hovering around $360 per kg. I find this to be an exciting moment in history. We are seeing commodity prices rise all around us. The population of the world is exploding. The Chinese are tightening their grips on their supplies of rare technical and rare earth metals. There is a need for cleantech like never before and here we have an element in very tight supply.


Tellurium (te-LOOR-i-em) is an element discovered by Franz Joseph Muller Von Reichenstein, a Romanian mining official in 1782. His work was forgotten until 1798 when a German Chemist Martin Heinrich Klaproth named the new element Tellurium and gave all credit for it discovery to Reichenstein.

Tellurium is element number 52 on the periodic table and is a semi-metallic, crystalline and brittle. It is usually found as a dark gray powder. Be wary when handling this element it can give a person a foul smell for a considerable amount of time.

The main supply source of tellurium is as a by-product of copper mining, approximately 90%. It is the rarest of all the by-product metals, with the exception of Gold. The amount of tellurium in the earth´s crust is about .005 ppm. There are estimates of 150-500 t annually produced. The amount produced is very difficult to verify. For example the USA, Australia, Belgium, China, Germany, Kazakhstan, Phillipines and Russia do not report how much they mine or recycle each year for national security reasons. According to the US National Renewable Energy Laboratory (NREL) the maximum possible annual production would be no more than 1,600 t per year. The global market for tellurium is miniscule compared to the copper market- in turn this gives little incentive to the mining companies to invest in better, more efficient ways of extracting it.

The uses of tellurium include alloying component, semi-conductors, photo-diodes, solar cells, blasting caps, optical storage (CD-RW), computer memory (RAM), pyrotechnics, glass, ceramic paints and thermoelectric cooling devices. The largest use is as an alloying component to steel, aluminum, copper, tin and lead. It is used to improve the machinability of steel and copper.


The most exciting use of tellurium is in photovoltaic cells made from thin films of cadmium telluride. These solar panels are cheaper in cost per watt of electricity generating capacity than the traditional silicon panels. The firms making these solar panels will need approximately 80-100 t of tellurium per gigawatt of photovoltaic cell production. As stated earlier the annual production estimate is 150-500t. That means that the solar industry itself could use up most of the world´s production of tellurium in the coming years. There is serious debate as to whether the amount of global supply can meet the need of the solar industry. For example in July 2009, India unveiled a US$19 billion plan to produce 20 GW of solar power by 2020. Under the plan, the use of solar-powered equipment and applications would be made compulsory in all government buildings, as well as hospitals and hotels. It has been said that this initiative alone will use up all the world´s production of solar cells.

In 2004 you could purchase tellurium for $10 per kg. Then the solar industry came along and disrupted the market. In August 2011 the price is hovering around $360 per kg. I find this to be an exciting moment in history. We are seeing commodity prices rise all around us. The population of the world is exploding. The Chinese are tightening their grips on their supplies of rare technical and rare earth metals. There is a need for cleantech like never before and here we have an element in very tight supply. The next few years are going to be a very interesting time in the commodities market. I look forward to seeing where tellurium goes from here.

By: Randy Hilarski - The Rare Metals Guy