Who mines the conflict metal in every phone — and its twin in every steel beam?

Tantalum is an electronics metal and niobium a steel metal. About 39% of the world's tantalum becomes capacitors — the small, temperature-stable components in phones, servers, cars' safety electronics, pacemakers and military circuit boards — 21% goes into chemicals such as optical-glass oxides and the lithium tantalate in smartphone radio filters, 16% into the sputtering targets that lay down barrier layers in every advanced chip, 11% into jet-engine and gas-turbine superalloys, 9% into mill products and 4% into cutting-tool carbides (Project Blue via USGS, 2022). About 89% of niobium goes into steel as ferroniobium: a few hundred grams per tonne make the high-strength steel of pipelines, bridges, high-rise frames, ships and car bodies. The rest makes superalloys for jet engines, niobium-titanium superconducting magnets for MRI scanners and particle accelerators, the C103 alloy of rocket thruster nozzles and, increasingly, battery anodes.

Tantalum comes mostly from Central Africa and niobium almost entirely from Brazil. USGS estimates that DR Congo mined about 1,300 of the world's 2,500 tonnes of tantalum in 2025 (52%), Rwanda 400, Nigeria 390, Brazil 190, China 80 and Australia 50 — Africa about 86% in all — although Congo's figure was revised up sharply on a government report and the trade press puts its share nearer 43%. Most African tantalum is dug by hand: 88% of Congo's 2025 coltan concentrate was artisanal. For niobium, Brazil mined about 104,000 of 112,000 tonnes (93%) and Canada 6,000; CBMM's Araxá mine alone supplies roughly three-quarters of the market, CMOC's Catalão mine and Canada's Niobec most of the rest. China holds the largest listed tantalum reserves (240,000 tonnes) and Brazil 14 of the world's 21 million tonnes of niobium reserves; USGS lists no reserve figure for any African tantalum producer.

Coltan is the Central African name for columbite-tantalite, a heavy black ore in which niobium and tantalum replace each other. It is mined by hand in eastern Congo, where armed groups have taxed and traded it since a tantalum price boom coincided with the Second Congo War in 2000 and a UN panel accused foreign armies and militias of financing the war with it. That history is why tantalum is one of the four '3TG' conflict minerals — with tin, tungsten and gold — covered by Section 1502 of the US Dodd-Frank Act (2010) and the EU Conflict Minerals Regulation (in force since January 2021), which require companies to trace where their supply comes from, and why the industry's ITSCI scheme bags and tags Congolese and Rwandan ore at the mine. The label became current again when the M23 rebellion took the Rubaya mines in April 2024.

Since 30 April 2024 the Rubaya coltan mines in Masisi, North Kivu — one of the world's largest coltan mining areas, with about 10,000 diggers — have been held by the AFC/M23 rebellion, which the UN says is backed by Rwanda. ITSCI suspended tagging in Masisi on 8 May 2024, so Rubaya ore cannot be traded legally. The UN Group of Experts on the DRC found that M23 controlled the trade and transport of 120–150 tonnes of coltan a month, taxed it for at least $800,000 a month and moved it into Rwanda, where it is mixed with Rwandan production and exported as Rwandan; in one week of March 2025 about 195 tonnes of Rubaya minerals crossed the Goma–Gisenyi border. Rwanda's coltan exports rose from 1,046 tonnes in 2021 to 2,384 tonnes in 2024, and Rwanda is now the largest source, by value, of China's niobium-tantalum ore imports. A US-brokered Congo–Rwanda peace agreement (June 2025) and the Washington Accords (December 2025) have not returned the mine to Kinshasa, which in February 2026 offered it to US investors; a landslide there on 28 January 2026 killed more than 200 people.

Because the largest single source of supply stopped and the market had no buffer. Tantalum ore averaged about $180 per kilogram of Ta₂O₅ in 2025 (USGS) — roughly $82 a pound. After the Rubaya landslide of 28 January 2026 halted artisanal digging, the CIF China price jumped about 27% to roughly $120 a pound, reached $160–165 by late February and $220–225 on 20 May 2026 (SMM), about 2.7 times the 2025 average, as stockpiling news drained cheap inventory; low-end deals still traded at $160 the same day. Tantalum has no exchange or futures contract — prices are trade-press assessments on thin volumes — so a single mine, a single border closure or a single stockpile order can move it by tens of percent in weeks. Niobium has no such volatility: ferroniobium sells at about $26–27 a kilogram on long-term contracts set largely by CBMM.

Because guidance electronics, jet engines and rockets cannot be built to specification without them, and the West produces almost none. Tantalum capacitors sit in missile, radar, avionics and satellite electronics, tantalum liners in anti-armour munitions and tantalum superalloys in turbine blades; niobium goes into engine discs, superconducting magnets and the C103 alloy of rocket nozzles. The United States imports 100% of both metals and has mined no tantalum since 1959. The Pentagon has banned tantalum melted or produced in China, Russia, North Korea or Iran (DFARS final rule, August 2022); the National Defense Stockpile's 2025 plan allowed purchases of 29 tonnes of tantalum and 136 tonnes of ferroniobium; and in September 2025 the Defense Logistics Agency signed a contract worth up to $100 million with Global Advanced Metals, the only US plant processing tantalum from ore. Both metals are on the final 2025 US Critical Minerals List and the EU's list of critical raw materials, and China — the largest buyer of tantalum ore — supplies 47% of US imports of tantalum metal and powder.

That's exactly what we do. We produce commissioned deep-dive reports for the tantalum and niobium chain — miners and traders of coltan and pyrochlore, processors, capacitor, semiconductor, superalloy, steel, aerospace and defence manufacturers, responsible-sourcing and due-diligence teams, metals traders — and for geopolitics researchers and think tanks, covering angles such as mine-to-capacitor supply-chain mapping, conflict-mineral and provenance risk, Great Lakes trade flows, Congolese and Brazilian supply scenarios, stockpile and sourcing rules, and price scenarios. Every report is source-cited — charts, maps and citations included — and built on the same open, verified data behind this dashboard. Email hello@mineral.watch with a short note on what you need and we'll come back with a scoped proposal.