Characterization and Geochemical Fingerprinting of Columbite‐Tantalite Minerals From South Kivu Province ( <scp>DRC</scp> ) Using Portable <scp>XRF</scp> Techniques

ABSTRACT Columbite‐tantalite (coltan) ore is one of the “3T” minerals, which contains technologically important metals, namely tantalum and niobium. Market demand for these metals is growing as technology evolves, making them critical to manufacturing industries. However, the mineral supply chains are required to be conflict‐free, so that manufacturers do not, even involuntarily, contribute to promote “blood minerals”. Such criticism has been evoked against some mineral processing companies in many conflict regions such as Sierra Leone and the Democratic Republic of the Congo (DRC). Columbite‐tantalite minerals can be fingerprinted using several analytical methods, which are fairly sophisticated and expensive. This study elucidates the use of a portable XRF (PXRF) analytical technique to define the fingerprint of columbite‐tantalite mineral ores from the South Kivu province of the DRC, in order to trace them along their supply chains. This study presents data of 15 samples from 4 artisanal mining areas, with discrimination diagrams. For the technique validation, the data were compared with those obtained by ICP‐AES and PIXE analysis, and a good correlation was found among them. XRD and SEM‐EDS analysis were performed to complete the characterization of the composite samples from the 4 regions. The health risks associated with the presence of children and pregnant women in the artisanal mines of South Kivu are also assessed on the basis of the radionuclide elements that columbite‐tantalite ore may contain.