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Roger Weller, geology instructor

Jennifer Starkey
Physical Geology
Spring 2005

                           Tantalum, Cell Phones, and War

            Do you have a cell phone?  If you don’t, then I’m quite surprised.  The truth is, I detest their obnoxious public attributes, their trendy appeal, and the fact that I am paying a lot of money to babble with only a couple people.  But alas, even I am beginning to want one-they’re just so darn convenient (and I am tired of being harassed by my friends).  A while back, I had taken a sociology class that, in one of the textbook chapters, revealed the direct correlation between cell phones and the raging war in the Democratic Republic of the Congo (DRC).  The chapter explained how guerillas are mining coltan, a nickname for the ore that yields tantalum (a high value element used in various electronic products including cell phones), to fuel the bloody war that has killed an estimated three million people thus far.  So I vowed not to buy a cell phone-ever. 

Now with the opportunity to research the subject, I have begun to find out the truth about the correlation between cell phones and the war in the DRC, including details involving the mining of coltan, sale, and production.  I am going to tell you what the situation really is involving the DRC, discuss what coltan is and how it is produced, and reveal what products result from the manipulation of this valuable metal. 

            The Democratic Republic of the Congo is suffering from an ongoing civil war that involves seven other African countries, and stems from a complicated web of conflict and foreign involvement.  In summary, Paul Harris from The Power and Interest News Report writes that ethnic genocide in Rwanda spilled over into DRC in 1994 and continued until the beginning of DRC’s civil war in 1998 with the death of former President Joseph Mobuto.  As a result various rebel groups rose up, exploiting the rich-resources the Congo had to offer by illegally mining and selling them to fund their cause.  The conflict is continuing to this day, even in spite of various peace treaties and cease fires (Harris).  Ian Redmond from the Gorilla Journal reveals many of the ensuing problems of illegal mining in the Congo.  As the rebels mine the coltan, they are destroying the environment around them.  They have cut down forests to clear for mines, which has been killing local guerilla populations.  They also hunt large prey, like elephants and gorillas among others, for food to the point of extinction.  Other problems include the exploitation of children working the mines, the danger of landslides in the mining process, and the pollution of streams by silt.  Rebel groups are also prone to murder civilians and interfere with any legal mining and trading of tantalum in the country (Redmond). 

The UN along with the support of various corporations are attempting to dissolve illegal mining in the Congo by encouraging people not to buy from suspected rebel traders.  This is difficult to do because it is nearly impossible to source the origin of any tantalum shipment, since it is sold several times in regional markets before it reaches industries.  Corporations who benefit from tantalum in their products deny any knowledge of their shipments deriving from rebel sources.  However, the civil war will continue as long as rebel groups can reap the benefits of mining tantalum and selling it to eager corporations as the modern world demands new high-tech products (Essick).  

              So what exactly is coltan?  In the DRC, it is the nickname for the ore columbite-tantalite.  The sole reason it is mined is to produce tantalum, which is a metal that can be refined and highly valuable on the world market.  Tantalum is the element Ta and is considered a transitional metal, with an atomic number of 73 and an atomic mass of 180.95 (Bentor).  The metal is prized for its useful attributes including having a very high melting point (2,996°), having good malleability and ductility, being resistant to corrosion and most acids, and having a great electrical conduct (Frost).  The primary mineral containing tantalum is tantalite, located in mines around the globe, but mostly in Australia.  Over 50% of tantalum mined derives from Australia, although prominent mines exist in Canada, Brazil, China, and Africa as well.   In fact, it turns out less than 10% of the world’s tantalum comes from Africa, including the DRC (Wickens).   

            In the DRC, coltan is found in alluvial deposits and streambeds, so that all miners have to do is loosen the substance with picks and shovels and sieve it through mesh.  The coltan is then bagged and sold cheaply to local traders, who in turn sell it to many regional traders, who sell it to international mineral trading companies.  Processing companies buy it up, the two main being H.C. Starck and Cabot, isolate the tantalum and turn it into a powder for manufacturers to buy and produce capacitors which sell to high-tech industries including Compaq, Dell, IBM, Motorola, and Nikia.  Tantalum today sells at around $100 a pound, compared to $50 before 2000 and $400 after with the exponential demand for it paralleling the world’s demand for high-tech products.  The United States is, not surprisingly, the biggest consumer of tantalum in the world (Essick).  So although not much of the tantalum used in the production of cell phones is from the DRC, there still exists a connection.

            Processing tantalum is difficult and requires several steps.  First, the tantalum must be extracted from the ore and separated from Niobium, the element near always found in combination with tantalum.  This is accomplished by treating the ores with a mixture of hydrofluoric and sulfuric acids at high temperatures, which then dissolve the elements along with many others.  A purified solution of tantalum is created by filtration via solvent extraction using methyl isobutyl ketone, a process known as liquid ion exchange.  The tantalum values in the solution are converted into potassium tantalum fluoride, tantalum oxide, tantalum carbide, tantalum chloride, and lithium tantalite, which are the only chemical compositions of tantalum of any economic value.  The tantalum powder used in capacitors that are put into various electronic devices is produced from tantalum fluoride through the process of sodium reduction at high temperature (Tantalum).  Below is a chart summarizing the many uses of tantalum in modern day products. 

Tantalum Product


Technical Attributes/Benefits

Tantalum carbide

Cutting tools

Increased high temperature deformation, control of grain growth

Tantalum oxide

- Camera lenses
- X-ray film
- Ink jet printers

- High index of refraction for lens compositions
- Yttrium tantalate phosphor reduces X-ray exposure and enhances image quality
- Wear resistance characteristics. Integrated capacitors in integrated circuits (ICs)

Tantalum powder

Tantalum capacitors for electronic circuits in medical appliances such as hearing aids, pacemakers, also in airbag protection systems, ignition and motor control modules, GPS, ABS systems in automobiles, laptop computers, cellular phones, Playstation, video cameras, digital still cameras.

High reliability characteristics and low failure rates, operation over a wide temperature range from –55 to +125°C, can withstand severe vibrational forces, small size per microfarad rating/electrical storage capability.

Tantalum fabricated sheets, plates, rods, wires

- Sputtering targets
- Chemical process equipment
- Cathodic protection systems for steel structures such as bridges, water tanks
- Prosthetic devices for humans – hips, plates in the skull, also mesh to repair bone removed after damage by cancer
- Suture clips
- Corrosion resistant fasteners, screws, nuts, bolts
- High temperature furnace parts.
- High temperature alloys for air and land based turbines (e.g. jet engines)

- Applications of thin coatings of tantalum, tantalum oxide or nitride coatings to semi-conductors
- Superior corrosion resistance – equivalent in performance to glass. Attack by body fluids is non-existent. Melting point is 2996°C, but protective atmosphere or high vacuum required. Alloy compositions containing 3-11% tantalum offer high temperature reliability, resistance to corrosion by hot gases.

Chart 1. Tantalum-Raw Materials and Processin. Tantalum-Niobium International Study Center.

          As you can see, tantalum is a valuable modern resource used in a variety of important fields.  6.6 million pounds of tantalum were used in 2000, approximately 60% of this used in electronics (Essick).  Tantalum powder, the key component of electronic devices, makes up 60% of the market value of tantalum (Tantalum).  Tantalum capacitors are proficient to function in small spaces, are reliable, and can withstand temperatures between –55
°C and 125°C, so they are used profusely in cell phones, cameras, and computers.  Tantalum is used in the alloys of the hottest part of a jet engine because of its high heat resistance capabilities.  Tantalum is the choice mineral used in heart pacemakers because of its reliability and long life and for the fact that it is completely resistant to body fluids.  In this respect, it can be used to reconstruct joints and tissues as well.  It is used in the chemical industry, coating equipment for protection against corrosion and tantalum carbide is so hard it can cut through steel easily (Frost).  With a mineral this valuable, it’s a good thing that tantalum is not being depleted in mines around the world.  Other deposits around the world are being located to mine and large quantities of the tantalum are being recycled (Wickens).

In conclusion, with my research I found out that there is connection between the production of cell phones and the war in DRC, although it not is not as drastic as I first heard.  Even though the war is still enduring, both the U.N. and corporations are working to keep illegal coltan off the market.  It was comforting to find out that most of the tantalum used comes from legal mines in Australia.  It was fascinating to discover the diverse properties of tantalum and find out about the expansive uses we get from it.  My research also reminded me that nearly all aspects of life are connected in some way.  I may just buy a cell phone now, but I’ll never talk incessantly on it in public areas.


Works Cited

            Bentor, Yinon. Chemical - Tantalum. May 30, 2005
            Essick, Kristi. “Guns, Money and Cell Phones.” The Industry Standard Magazine 11 June

Forest, Michael. “Tantalum-Sources and Properties of Tantalum.” Materials World Oct.

            Harris, Paul. “Congo’s International Civil War.”
The Power and Interest News Report

(PINR). 5 Aug. 2003.
Redmond, Ian. Coltan Boom, Gorilla Bust. Gorilla Journal 2001

            Tantalum-Raw Materials and Processin. Tantalum-Niobium International Study Center.

            Wickens, Judy. Developments In the Tantalum Market.  T.I.C. Presentation. 2004.