Panning for alluvial samples in a live bed to obtain coltan concentrates (French Guiana, 2013).
© BRGM - M. Chevillard
Niobium (Nb) and tantalum (Ta) are critical substances for the European economy because of shortages in their supply and their role in the energy transition.
In this context, the aim of this study was to assess the geological and economic potential of coltan ore in French Guiana and to put it into perspective on the scale of the South American market.
Coltan mineral deposits could indeed be of economic interest because of:
- The geographic accessibility of the mineral occurrences;
- The simplicity of mining and exploiting the ore by small-scale or semi-industrial methods already used for mining alluvial gold;
- The presence of a marketing channel in South America (Brazil) and North America (Canada, United States).
Confirming the attractiveness of this channel, three exclusive prospecting permits (PERs) were recently awarded for these two metals and other related substances, including lithium.
There is no single large area of mineral deposits in French Guiana, but a multitude of small creeks rich in heavy minerals, including coltan. Despite uncertainties regarding the reliability of historical data, total resources have been estimated at between 850 and 1,130 tonnes. Based on the composition of these concentrates and Nb and Ta prices, the resources could represent a modest economic potential of around $10 million. It should be noted, however, that the purchase prices of concentrates by refiners are unknown. They are lower in relation to the metal content.
Using the results
This study – carried out as part of the 2019 joint work programme with the Water and Biodiversity Directorate of the Ministry of the Environment, which relates mainly to mineral resources – was published on the MineralInfo website in February 2020.
It should be noted that coltan mining techniques are identical to those used for the exploitation of alluvial gold, which is actively pursued in French Guiana. The concentrates could be extracted using responsible mining techniques and then transported to neighbouring countries such as Brazil, where companies are already in operation carrying out the final stages of metallurgical processing.
- Water and Biodiversity Directorate (DEB) of the Ministry of Ecological Transition (MTE)
Distribution of the different tantalum and niobium occurrences and deposits in South America according to their respective grades.