ASSESSMENT OF TRACE AND RARE EARTH ELEMENT DISTRIBUTION AND SPECIATION IN BAUXITE DEPOSITS ACROSS EKITI AND ONDO STATES, NIGERIA

Abstract

The growing significance of rare earth elements (REEs) in advanced electronic technologies and the nuclear industry, coupled with concerns about geopolitical dynamics and supply market vulnerabilities, has reignited global interest in securing domestic and economically viable sources of REEs through dedicated research and developmental pursuits. Bauxite, a naturally occurring mineral primarily composed of aluminum, has been identified to harbor an abundance of sought-after rare earth minerals, thereby rendering it a promising unconventional reservoir of REEs contingent upon geological and mineralogical characteristics. Nigeria, endowed with substantial bauxite deposits prominently situated in Ondo and Ekiti states, stands to offer an intriguing avenue for exploration. In this study, the utilization of inductively coupled plasma mass spectrometry (ICP-MS) facilitated the quantification of trace elements within samples obtained from six distinct production sites spanning Ondo and Ekiti states in Nigeria. The aim was to elucidate correlations between multi-elemental REE compositions and geographical origins. Employing both single quadrupole (SQ) and multi-collection sector field (MS) modes, concentrations of Pb, Cd, As, Zn, Mn, Al, Ca, Ni, K, Na, Mg, Cu, Fe, Ti, P, Cr, and Si were rigorously determined. Remarkably, ICP-MS analysis consistently revealed a palladium (Pd) concentration of 228.05 ppb across all sampled materials, factoring in a dilution factor of 175x. Consequently, the actual concentration of the digested solution was established at 39.91 ppm mg/L. The outcomes of this investigation hold potential significance in categorizing Nigerian bauxite deposits as viable REE sources, as well as in engineering tailored techniques to efficiently recover these elements. Such findings harbor promising economic prospects for the nation, positioning the solid mineral sector as a pivotal driver of Nigeria's burgeoning economy.