10 April 2008

What is coltan and what does it have to do with my cell phone?

UPDATE (11 Feb 2014): This article has been substantially revised since initial posting.

"Coltan" is short for columbite-tantalite, a mineral from which niobium (AKA columbium) and tantalum are extracted.  It's a mineral found mainly in Nigeria, Rwanda, Mozambique, Malawi, and Congo-Kinshasa (Democratic Republic of Congo). "Tantalite" is the usual internationally-used name for this mineral, which--depending on the grade--carries different concentrations of either tantalum or niobium.

About Tantalum

Niobium is usually used in the production of high-strength steel alloys, not semiconductors; tantalum is used in the production of cell phones because, as a superconductor, it sharply reduces the amount electricity required.1 Superalloys account for about a fifth of consumption. Tantalum has an extremely high melting point, 3017° C, and is an excellent conductor.2  It can be made extremely strong for cutting tools, resists corrosion, and can be used to make surface acoustic wave (SAW) filters used in cell phones, etc.  In cell phones it is also used in capacitors and the lenses of cameras.

The Supply

Not all, or even an especially large proportion, of tantalum/niobium comes from Africa; most comes from Australia or South America, and much comes from minerals other than tantalite; however, tantalite is one of the more important ones, commercially (often any commercially significant tantalum-bearing mineral is called "tantalite.")3
Cell Phone Recycling Guide: The legacy of "blood diamonds" is well known, however the fact that a similar arrangement exists to mine coltan (Columbium Tantalum) is lesser known. Tantalum is a superconductor, one of the best on Earth. It is used to coat capacitors to help them create more power from less energy so that your cell phone no longer needs a battery larger than the phone itself. In war torn central Africa, people are forced into modern day slavery to mine this rare element, which is then sold to fund the wars in this region. Recently the majority of Tantalum production has shifted to Australia, however it is a rare element, so decreasing demand helps decrease the likelihood that manufacturers will turn to African supplies.
A lot of the moral headaches associated with African tantalite arise from "artisanal mining" (artisanal & small scale mining, or ASM) only a part of which comes from areas controlled by warring militia from Congo-Kinshasa (Democratic Republic of the Congo).  One of the features of the Dodd-Frank Act was a provision requiring companies reporting to the Securities Exchange Commission (SEC) to say whether or not the tantalum they bought came from the conflict region.4
Tantalum Market Overview: A major problem with the whole issue of conflict tantalum is the ability to track tantalum back through several stages to its original source. A key element of this is the concept of “bag and tag”, which essentially means identifying tantalum ore at the source of production and providing the means to track it down the chain.
The industry itself has introduced several schemes to address this. One is the Conflict-Free Smelter (CFS) Program, which was developed by the electronics industry to eradicate unethical sources of raw materials from the supply chain. Driven by the Electronics Industry Citizenship Coalition (EICC) and Global e-Sustainability Initiative (GeSI), the CFS Program is being adopted by the automotive, aerospace and other metal-consuming industries and a growing number of tantalum smelters are now certified as conflict-free.
Since originally posting this essay, the locus of concern about "conflict exotics" (i.e, artisanal mining of exotic metals and strategic materials in warzones, usually under duress) has shifted from the DRC to the Central African Republic (CAR).

  1. "Niobium: Market Outlook"; "Tantalum: Market Outlook," Roskill (accessed 11 Feb 2014)

  2. "Tantalum Market Overview," Minor Metals Trade Association (accessed 11 Feb 2014).  The MMTA report mentions:
    For most of the 2000s it was often reported that the majority of the world’s tantalum resources were located in Central Africa and in the Democratic Republic of Congo (DRC) in particular. Towards the end of the decade, however, the Tantalum-Niobium International Study Center, the industry’s principal forum, estimated that some 40% of the most likely global resource base is in Brazil and elsewhere in South America, followed by Australia, with 21%. Central Africa was estimated to account for less than 10%.
    Is this true, or was "artisanally mined" tantalum accounted for as contribution from Brazil?

  3. Tantalum - Raw Materials and Processing," from website for Tantalum-Niobium International Study (TIS) Center (Lasne, Belgium--accessed 11 Feb 2014). A major development since originally posting this article was the collapse of demand/prices and some national suppliers in 2009-2012.  

  4. See Ken Matthysen & Iain Clarkson, "Gold and diamonds in the Central African Republic: the country’s mining sector, and related social, economic and environmental issues" , ActionAid Nederland and Cordaid (Feb 2013), p.11, for the Dodd-Frank Act disclosure requirements re: tin, tungsten, tantalum, and gold.

Sources & Additional Reading

"Cell Phone Recycling Guide," Phone Scoop blog (via Textually blog, 19 Jan 2005)

John F. Papp, "Mineral resource of the month: Niobium (Columbium)" (December 2007 accessed 11 Feb 2014); and Larry D. Cunningham, "Mineral Resource of the Month: Tantalum" (August 2004), both from GeoTimes blog. Both discuss the applications for the materials (including substitutes).

"Columbium (Niobium) and Tantalum" , Larry D. Cunningham, USGS (1999)

ADDED 13 Nov: "Mobile phones link to bloody Congo conflict" (Independent.ie, 9 Nov 2008)

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