The term conflict minerals is used for minerals mined in conditions of armed conflict and human rights abuses. With regard to the conflict in the eastern provinces of the Democratic Republic of the Congo columbite-tantalite (coltan), cassiterite, gold as well as wolframite have been named (e.g. in the US Dodd-Frank Act) as conflict minerals.
“Coltan” is a trade name for tantalum ore concentrates containing minerals of the columbite-tantalite group [(Fe,Mn)(Nb,Ta)2O6]. The most important application of tantalum is in ultra-miniaturised, high performance capacitors used by the modern microelectronics industry for mobile phones, laptops and flat screens. About 40 percent of the “Coltan” used for the production of tantalum are produced in African countries, mainly by artisanal mining methods.
The most important ore mineral for tin is cassiterite (SnO2). Major uses for tin metal are in the electronics industry as solder, as tin plate for food and beverage cans, in the production of bronze, and in chemicals. The African tin production (about 5-6 percent of the world production) is mainly from the Democratic Republic of the Congo, Rwanda and Nigeria.
The major sources for tungsten are scheelite (CaWO4) and the minerals of the wolframite solid solution series [(Fe,Mn)WO4]. Wolframite is the dominant tungsten mineral in Central Africa making up about 4 percent of the world production from primary ores. Tungsten has unique properties and is used for tungsten carbide in cutting tools, for the production of high speed steel as alloying component, and for light bulbs as filament.
Gold is also regarded as a conflict mineral, but an AFP method for artisanal gold is not yet available. In nature, gold commonly occurs as native metal (Au) or forms alloys with other metals, especially silver. Today gold is principally used as a monetary metal and in jewelry. Other applications for gold are in the electronics sector and dentistry. About 20 percent of the world’s gold production derives from Africa with South Africa, Ghana and Tanzania as major producers. Reliable production data for gold in the Great Lakes region are not available.