Mineralogical Characteristic and Beneficiation Evaluation of a Ta-Nb-Li-Rb Deposit

Abstract

In order to rationally develop and utilize a Ta–Nb–Li–Rb rare metal deposit in Jiangxi Province, the mineralogical characteristics of the ore, such as chemical composition, mineral composition, modes of occurrence of major elements, and dissemination characteristics of major minerals, were investigated in detail based on optical microscopy analysis, chemical analysis, X-ray diffraction analysis, artificial panning, mineral liberation analysis, and electron probe microanalysis. The results reveal that the main useful elements in the ore are tantalum, niobium, lithium, and rubidium. Niobium and tantalum are mainly found in the mineral form of columbite. Columbite has particle sizes ranging from 0.5 mm to 0.012 mm, with the most common sizes being 0.3 to 0.044 mm. Intergranular dispersion accounts for 73.92% of the embedding in columbite, whereas inclusions account for 26.08%. Lithium is found mostly in zinnwaldite, while rubidium is found primarily in feldspar and zinnwaldite, both in a homogenous distribution. The beneficiation evaluation of this ore was conducted based on the mineralogical characteristic, and it indicates that the tantalum-niobium–lithium–rubidium rare metal resources, as well as the feldspar and quartz non-metallic resources in the ore, can be effectively and comprehensively recovered using gravity, magnetic, and flotation separation methods. A staged grinding and separating process was adopted which could produce tantalum–niobium mineral concentrates (18.34% Ta2O5 at a recovery of 47.65% and 41.33% Nb2O5 at a recovery of 69.96%), zinnwaldite concentrate (2.41% Li2O and 0.80% Rb2O at a recovery of 81.82%) and other concentrates such as cassiterite, topaz, galena, sphalerite, and feldspar. This study provides suggestions for the rational development and utilization of the deposit and provides a reasonable level of recovery prediction.