CHARACTERIZATION AND BENEFICIATION OF NASARAWA-EGGON LEAD-ZINC ORE, NASARAWA STATE, NIGERIA
Abstract
Characterization and flotation studies were carried out on the Nasarawa-Eggon lead- zinc ore sample through Chemical analysis, Mineralogical analysis, Petrological analysis, Work Index evaluation, Particle size/mineral assay analysis, Liberation studies Bulk Froth Flotation and development of a flow sheet. The chemical analysis was carried out using XRF machine to estimate the elements in the ore sample, the analysis revealed that the ore deposit is mainly made up of 16.78%Pb, 12.60%Zn, 21.25%Si, 2.03%Fe, 1.58%Mn, 1.64%Cu. The mineralogical analysis consist of XRD analysis which was carried out using XRD machine, SEM analysis using SEM and Petrological analysis using petrological microscope after thin sectioning. The XRD analysis revealed that the predominant crystalline minerals in the ore sample are Quartz (SiO2), Galena (PbS) and Sphalerite (ZnS) which showed a high phase of 45.2%, 38.7% and 16.0% respectively, the SEM analysis result revealed that the minerals in the ore have different particle sizes, are separated by grain boundaries and are also finely disseminated within each other and the Pretrological analysis showed that the Sulphide minerals (PbS and ZnS) and Quartz occur in close spatial associations and also as intergrowths. The particle size/mineral assay analysis showed that the minerals were distributed on the various sives sizes. The liberation size of the ore was hard to determine because of the dissemination of the minerals within each other. Meanwhile, after the chemical analysis of the various sieve sizes using XRF machine, the mineral has a high degree of freedom the sieve size of -125+90µm. The work index of the ore was evaluated to be 11.64KWh/t using the Bond‘s energy method. A bulk flotation test was carried out in the reverse form at -125+90µm sieve size and the ore was upgraded from 16.30%Pb and 9.79%Zn to 42.43%Pb and 34.57%Zn with 81.65% and 87.30% recovery respectively. Based on the results obtained from the tests conducted, block diagrams where us to
develop a flow sheet for the beneficiation of the Nasarawa-Eggon lead-zinc ore. The results obtained were compared with that of the literatures cited, the research bridged the existing gap in the previous researches of not adequately providing useful information on the beneficiation parameters of Nasarawa-Eggon Lead-Zinc ore. Nasarawa Eggon Lead-Zinc ore may be another potential source of Lead-Zinc ore deposit that can be beneficiated and supplied to iron and steel making industries in the country.