Coltan

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A coltan step, 6.0 x 2.5 x 2.1 cm

Coltan (also coltan ) is a tantalum - ore . The name "coltan" is derived from the mineral group Col umbit- Tan talit from. The terms “coltan” and “columbite-tantalite” are always used when the individual minerals cannot be determined without appropriate tests or differentiation is not necessary.

Chemical composition

The chemical composition of this mineral group is very variable. The actual columbite-tantalite family consists of the columbite mixed crystal series (with the end members columbite (Fe) and columbite (Mn) ) and of the tantalite mixed crystal series (with the end members tantalite (Fe) and tantalite (Mn) ). There is the possibility of mixed crystal formation between all four end links, although this is not complete in certain areas. Occasionally the antimony-rich minerals stibiotantalite and stibiocolumbite are also included. Primarily bound to crystalline rocks , including alkali pegmatite veins, these minerals are often found in secondary deposits, for example in heavy mineral soaps.

advancement

In 2018, 1800 t of tantalum, which is mainly extracted from coltan, were produced worldwide, with 710 t in the Democratic Republic of the Congo , 500 t in Rwanda , 150 t in Nigeria , 120 t in China , 100 t in Brazil, 100 t in Australia , and 70 t in Ethiopia t and other 100 t.

In the Democratic Republic of the Congo, miners extract concentrates with up to 40 to 45% tantalite from the soil by wet sieving and gravity separation. Also Glencore played a significant role in coltan extraction in Central Africa. Glencore planned to become the world's largest producer of coltan through its subsidiary Katanga Mining Limited. The mining quantities should be increased to 30,000 t by 2015.

smelting

Around half of the coltan extracted worldwide is bought and smelted by HC Starck (Germany) . Other important processors are (as of 2009) Treibacher (Austria), Cabot (USA), Mitsui (Japan) and Ulba (Kazakhstan).

use

Tantalum is extracted from coltan, which is required to manufacture the tantalum electrolytic capacitors used in almost every electronic device .

Conflict mineral

Coltan is classified as a conflict mineral.

The mining of coltan in the Kivu region in the Democratic Republic of the Congo continues to attract attention worldwide . The income from mining and poorly controlled embargoes enable local militia leaders to pay soldiers, buy weapons and continue the civil war . Ernesto Cardenal addressed the problematic mining methods of coltan in the Congo in his poem El Celular ( Das Handy ).

Many companies that process coltan refrain from processing coltan from the Democratic Republic of the Congo. Examples are HC Starck , Traxys, Samsung and Intel . In 2003 HC Starck was accused of financing rebel groups in the Congo, but now the company has promised to only process conflict-free tantalum certified by the Conflict Free Sourcing Initiative (CFSI).

literature

Web links

Wiktionary: Coltan  - explanations of meanings, word origins, synonyms, translations

Individual evidence

  1. Abraham J. Padilla: Mineral Commodity Summaries 2019. (Pdf, 95.3 KB) US Geological Survey, National Minerals Information Center (USGS), 2019, p. 164 , accessed on June 4, 2019 .
  2. Chantal Peyer: Contrats droits humains et fiscalité: comment une entreprise dépouille un pays. Le cas de Glencore en République Démocratique du Congo. ( Memento from July 22, 2015 in the Internet Archive )
  3. Simone Schlindwein, Dominic Johnson : How the blood is washed from the ore. In: the daily newspaper. 4th / 5th July 2009.
  4. Ernesto Cardenal: Poema El celular , accessed February 19, 2020
  5. HC Starck receives certification for the processing of conflict-free tantalum raw materials for the fifth time. (No longer available online.) HC Starck, January 19, 2016, archived from the original on August 11, 2016 ; accessed on August 11, 2016 . Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot / www.hcstarck.com
  6. Gianluca Fiore Mezzo: Traxys Rejects Claims of Anonymous 'Blood trading' in Lead Ore and coltan with DR Congo. http://www.ibtimes.co.uk/ , June 18, 2012, accessed August 11, 2016 .
  7. environment and social report. (No longer available online.) Samsung, 2008, archived from the original on June 16, 2016 ; accessed on August 11, 2016 . Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot / www.samsung.com
  8. Carsten Drees: Coltan: Blood sticks to almost all of our smartphones. mobilegeeks.de, September 21, 2015, p. 1 center , accessed on August 11, 2016 .
  9. Philipp Mimkes: The Bayer subsidiary and the war in Congo. In: archiv.labournet.de. March 3, 2003, accessed May 1, 2018 .
  10. Laurin Meyer: Fairly traded smartphones: Telephone calls without pain . In: The daily newspaper: taz . September 8, 2015, ISSN  0931-9085 ( taz.de [accessed June 2, 2018]).