What are the uses of Coltan

  Coltan (also Koltan) is a raw ore in Central Africa, from which the metal tantalum (Ta) is primarily extracted. The name "Coltan" is derived from the mineral group Columbit-Tantalit off.

The chemical composition of this mineral group is very variable: The pure metal oxides niobite (columbite) and tantalite are the end members of a natural mixture of the general chemical formula (Fe, Mn) (Nb, Ta, Sb)2O6 to watch. Among the many varieties, the most important are the iron-rich mineral ferrotantalite or ferroniobite and the antimony-rich stibiotantalite or stibioniobite. Primarily bound to crystalline rocks, e.g. bound to alkali pegmatite veins, these minerals are often also found in secondary deposits, e.g. in heavy mineral soaps.

Central Africa's coltan mining is mainly concentrated in the Kiwu Lake region in the Democratic Republic of the Congo. In the coltan mines of Central Africa so-called "Local diggers" ("Creuseurs") concentrates for further smelting from the soil by wet sieving and gravity separation. The peak values ​​in these concentrates are 40 to 45% tantalite (tantalum oxide Ta2O5).

"The connection between the dwindling habitats of great apes and the rapidly growing numbers of cell phones is shown by a study by the Worldwatch Institute in the USA. The researcher and author of the study Erik Assydourian proves that the mining of the ore coltan, which is used for the production of the Cell phones are needed and are practically only found in the Congo, the monkeys are increasingly being displaced. According to Assydourian, this is also due to the lack of willingness to recycle cell phones and the raw materials for new devices to be obtained from nature In 2005 there were around 2.1 billion cell phones worldwide. "

Other significant tantalum-niobium deposits can be found in Brazil, Canada and Western Australia.


The metal Tantalum Due to its high temperature and corrosion resistance, it is widely used in industry, including for the manufacture of surgical instruments and in high vacuum technology. For some years now, it has also been used in modern microelectronics for the production of the smallest capacitors with high electrical capacitance, which are used in cell phones and laptops, for example.

In December 2000, the high demand for such devices led to a multiplication of the world market price for tantalum (480 dollars / kg), which at times even exceeded the price of silver. Then the price leveled off again and in the spring of 2005 reached a value of less than 80 dollars / kg.

The high profits and lack of government surveillance during the civil war in the Democratic Republic of the Congo resulted in completely haphazard mining activities. Serious environmental damage was the result. Among other things, larger areas of the already greatly reduced habitat of the gorillas were destroyed.

At the same time, the income from mining and poorly controlled embargoes enabled local militia leaders - especially rebels of the Rassemblement Congolais pour la Démocratie (RCD, “Congolese Collection for Democracy”) - paying soldiers, buying weapons and continuing the civil war.


The metal niobium (Nb) is chemically closely related to tantalum. This is how it should be at the moment. replace more expensive tantalum in the creation of capacitors. It is also used for the metallurgical production of hard and heat-resistant alloys (superalloys) for gas turbines and rocket parts.

The main supplier of niobium is the low-iron mineral pyrochlore, which, in addition to Nb, contains varying proportions of other cations (Ta, Ti, Ca, Na etc ...). It is mined in the Kivu region in eastern Congo.

Links to the political situation in the main coltan mining area

  • The Impact of Coltan Mining on Gorillas and other Wildlife in Eastern DR Congo
  • SZ article: "War for raw materials"
  • / Podcast from DRS2: "Arms against diamonds in the Congo"
  • Should German interests be represented in the Congo?


Categories: Mineral Group | metal