CHEMICAL AND MINERALOGICAL CHARACTERISATION OF FILIN-KOKUWA GOLD ORE DEPOSIT TOWARD DEVELOPMENT OF ITS PROCESS ROUTE

Abstract

This research was carried out to investigate the chemical, mineralogical and comminution characteristics of Filin-Kokuwa gold ore deposit and its subsequent processing to retrieve gold metal. Samples of the gold ore were sourced from different pits along granite outcrops situated at Toro LGA, Bauchi State. Characterization of the sourced ore was carried out using energy dispersive x-ray fluorescence spectrometry (ED-XRF), atomic absorption spectroscopy (AAS), petrological analysis, scanning electron microscopy coupled with energy dispersive spectrometry (SEM-EDS), and X-ray Diffractometry (XRD). Subsequently comminution and liberation studies were carried out, while sluicing and amalgamation were conducted to recover gold metal. The results obtained revealed that Filin - Kokuwa gold ore approximately assayed 15 ppm Au alongside other element. Microscopic analysis of the ore revealed coarse-packed mineral grains characterised by cleavages. Major minerals identified were pyrite, quartz, iron oxide, orthoclase, and biotite. Further qualitative analysis revealed non-equiaxial mineral grains (light grey), unevenly distributed across the dark-grey ore matrix. The area analysis of the ore revealed the principal elements within the ore as Si, Al, K, C, and O. The ore’s diffractogram revealed extensive diffraction gold mineral peaks such as Au2Pb and Na3AuO2 alongside other minerals like Cu4O3, ZnO, and Pb3O4.Comminution and liberation studies revealed that the ore’s mesh-of-grind and actual liberation size were 210 μm and 63 μm, respectively. At the same time, the ore’s work index was evaluated as 18.35 kWh/ton. Finally, 3 g of gold metal was recovered after processing translating to a grade of 18 carats and recovery of 0.006% in the concentrate. This study therefore, established that, the result obtained indicates that the deposit could be explored for exploitation.