In the past two decades, there has probably been no time when coltan has been discussed as much as it is today. Initially brought to global attention in the early 2000s, coltan was wrongly portrayed as the main cause of the conflict in Eastern Congo and was subsequently labelled as a “conflict mineral.” However, following the capture of Goma by the M23 rebel group in January 2025, supported by the Rwandan Defence Forces (RDF), international media have once again spotlighted coltan as a key element of the conflict. This time, however, the term “conflict mineral” has been replaced with the label “strategic mineral.”
Given the current attention surrounding coltan, it is essential to understand what coltan is, why and by whom it is considered strategic, and where it is found. In this analysis, we will also explore how the coltan supply chain has evolved in light of the ongoing conflict in Eastern Congo.
What is coltan, and why is it a “strategic” mineral?
The term “coltan” was coined by Congolese miners to refer to columbite-tantalite, which consists of two minerals: columbite, containing niobium (Nb), and tantalite, containing tantalum (Ta). Therefore, it is more accurate to refer to the minerals as tantalum and niobium.
The European Union classifies both tantalum and niobium as strategic and critical raw materials due to their importance in the energy and digital transitions, as well as their relevance to defence and aerospace industries. In simple terms, these minerals are essential for the prosperity of European industry. Tantalum is used in numerous metal alloys and is vital in several industries. In the digital sector, it is used in mobile phones, computers, and automotive electronics. In aviation, it is used in turbine blades for aircraft engines and land-based gas turbines. The military relies on tantalum for missile parts, night vision goggles, and GPS systems. Niobium is primarily used in alloys such as stainless steel, improving their strength at low temperatures. It is used in jet engines, rockets, beams and girders for buildings, oil rigs, and pipelines.
Europe is not the only entity recognizing the strategic importance of tantalum and niobium. The United States, Japan, and China have all taken steps to secure their supply chains for these minerals (see table below).
Where are tantalum and niobium found?
For mineral-producing countries, niobium and tantalum are also regarded as strategic minerals, though for different reasons. Brazil, for example, has listed niobium as strategic due to its economic importance and its near-global monopoly on production—Brazil accounts for 92% of the world’s niobium supply. Brazil is also a major supplier of tantalum, ranking as the world’s third-largest producer in 2024, as tantalum is often found alongside niobium.
In the Southern Hemisphere, Australia, once a dominant producer of tantalum, up to 45% of the global production in 2000, has seen a decline in output due to the economic crisis of 2008, which caused the closure of its two largest tantalum mines. However, the Australian Department of Industry, Innovation and Science released its Critical Minerals Strategy 2019 ambitions to position Australia as a world leader in the exploration, extraction, production and processing of tantalum.
The closure of industrial mines after the 2008 economic crisis, combined with an increase in the tantalum price in 2011, double the level of 2010 or triple of 2009, paved the way for artisanal miners. Rwanda and the Democratic Republic of Congo (DRC), whose productions are solely based on artisanal mining, have become the largest global suppliers of tantalum, a position they continue to hold in 2024.
The smuggle of the Congolese coltan
Yet, it is an open secret that a significant portion of minerals, including coltan, labelled as Rwandan is smuggled from the DRC –Global Witness puts the figure at 90%– and even the Rwandan President no longer tries to conceal.
However, smuggling of coltan into Rwanda predates the M23’s arrival in the region. It has long been a source of funding of belligerents of the 1996-1997 and 1998-2003 wars and Congolese armed groups afterwards. The coltan-rich regions in Congo lie in North and South Kivu provinces, which are separated from Rwanda by the Kivu Lake and the Ruzizi River.
In North Kivu, the region of Rubaya provides 15% of the world wide supply. Before taking full control of Rubaya, the M23 negotiated a share of the coltan with the PARECO-FF, a Congolese armed group controlling mines. In April 2024, M23 fully took over Rubaya and enforced a strict organisation of the mineral trade. According to local sources, which prefer to remain anonymous, M23 combatants patrolled Rubaya town to ensure that traders and diggers sold minerals only to M23-authorized Congolese and Rwandan traders. These traders offered good prices, paid in cash, and immediately bought all the stocks.
Before the capture of Goma, the coltan transport route from Rubaya to Rwanda was a long buckle (see the maps). The same local sources found out that trucks were loaded with minerals in Rubaya and took the road to Mushaki, then Kitshanga, Tongo and then to Kalengera. At Kalengera, trucks were weighted and then continued the road to Kibumba, Buhumba, and finally entered in Rwanda. They noted that this road was built using forced labour of the local population (the ‘salongo’).
In January 2025, the M23 expanded further in South Kivu, taking control of the towns of Minova, Shanje and Lumbishi, which are important trading hubs of minerals extracted in Kahele territory. During their advance in Kalehe territory, the M23 made of the ports of Kinyezire and Muhini (both in Nyamukubi) and Kasunyu (in Minova), a priority to transport minerals on motored pirogues across the Kivu Lake.
So far, the M23 has not penetrated in the territory of Shabunda, which is also rich in gold, cassiterite and coltan. M23, FARDC and Wazalendo (a coalition of non-state armed groups fighting alongside FARDC as allies) were fighting in Burhale, between Bukavu and Nzibira, making the passage of minerals impossible. Nzibira is a major collecting and selling hub of minerals coming from Walungu and Kabare.
The situation of minerals extracted in Mwenga territory is similar. Normally, traders would follow the route Kitutu – Kamituga- Kasika- Bukavu, but early March 2025, M23, FARDC and Wazalendo were still fighting in the town Mwenga, between Kamituga and Kasika, which impeded traders to move their minerals. It is likely that trading houses in Mwenga and Nzibira are piling up the coltan, and these stocks will be a direct target for the armed group that will eventually control the trade hubs: a scenario that has already unfolded in Bukavu, where, according to local civil society actors, AFC/M23 elements looted the local company CJX Minerals, on 20 February 2025.
What are the consequences of the conflict on the global market of tantalum and niobium?
There are no official prices for tantalum and niobium as they are not traded on metal exchanges like the London Metal Exchange. However, Shanghai Metal Market has not reported a sudden skyrocketing increase neither in tantalum (from USD 195/kg in January to USD 207/kg in March 2025) or in niobium prices, probably because Rwanda and DRC continue to export coltan, despite the ongoing conflict. It is uncertain how the market would react to an effective stop of the Rwandan and/or Congolese coltan export. However, despite being the current biggest producers of tantalum, it is possible that other countries, such as Australia, Brazil, and Nigeria, manage to meet global demand, by raising their production, and especially if the stop of Rwandan and Congolese coltan export causes a price increase.
A potential ban on Rwandan minerals export, as suggested by the DRC government would likely harm Congolese artisanal miners, who have no savings to cope with a loss of income. Moreover, a ban would only affect Rwanda’s economy if China and the United Arab Emirates, which together account for 82% of Rwanda’s coltan exports, enforce the sanction. This seems unlikely. Anonymous sources have told IPIS that Chinese and Lebanese buyers based in Rwanda continued to buy coltan, possibly at a lower price due to the withdrawal of other purchasers. In fact, the NGO HIVE has identified at least 4 exporters based in Rwanda who have significantly increased their export of coltan between 2023 and 2024, supporting the overall growth in Rwanda’s coltan exports.
In response to these developments, Belgium, the UK, Canada, and Germany have cut cooperation aid. The EU, for its part, has imposed sanctions including a ban on travel to the EU and a freeze on assets in the Union for nine Rwandans, including three high-ranking members of the Rwandan army implicated in the invasion of the DRC. The US has also sanctioned James Kabarebe, Rwanda’s Minister of Regional Cooperation, for his alleged ties to the M23. Nevertheless, these international reactions against Rwanda have disappointed the Congolese government which called on American fighting forces on the ground in exchange of access to strategic minerals. It may show despair but lately, President Trump showed appreciation to trade US support for raw materials.
Further reading
This briefing was produced with the financial assistance of the European Union. The contents of the editorial is the sole responsibility of IPIS and can under no circumstances be regarded as reflecting the position of the European Union.
