Mineralogical analysis and geochemical characterization of mineralized pegmatite of Kibaran belt through optimization of columbite-tantalite and cassiterite of Kabarore mine site in Burundi

Abstract

Tantalum (Ta), niobium (Nb), and tin (Sn) are important metals due to their valuable contributions as high-technology products and the innovations derived from them. They are extracted from pegmatites, granites, etc. as columbite-tantalite and cassiterite. Thus, the pegmatite ore from the Kabarore mine site in the northeastern part of the Kibaran belt precisely in the north of Burundi was investigated by subjecting it to X-ray fluorescence spectrometry (XRF), X-ray diffraction (XRD), Microscope analysis, Electron probe micro-analyzer-Energy Dispersive Spectroscopy (EPMA-EDS) together with the investigation of modeling of pegmatite orebody in the site. It is noted that the site has Phyllite, sandstone, pegmatite, tourmaline, lateritic soil, vein quartzite, basic rock, and laterite, and the orientation and shape of pegmatite orebody in the 3-D model is from southwest to northeast with a slight branching out in its eastern part. XRF results showed that the common oxide minerals in the site are silica SiO₂ (54.24 wt%), Al₂O₃(34.47 wt%), K₂O(1.007 wt%), and Fe₂O₃(0.5356 wt%), while the rare elements Ta₂O₅, Nb₂O₅, and SnO₂ have 0.015 wt%, 0.0243 wt% and 0.02867 wt% respectively. XRD examination indicates that the kaolinite mineral is reduced after gravity separation. Through Microscope analysis, EPMA, and SEM-EDS, different microzones have been identified for tantalite and columbite, where the high average content of Ta and Nb are 41.28 % and 38.06 %, respectively.