Iperindo lode gold is one of the few primary gold deposits known in Nigeria. The mineralized lodes generally comprise highly silicified fine-grained foliated biotite gneiss typically intruded by both discordant and concordant pegmatitic quartz-feldspar veins. The research investigates the work index of Iperindo lode deposit at Ilesha goldfield in Osun state, Nigeria. The sample of the gold ore was sourced from Iperindo at Ilesha Local Government Area of Osun state, Nigeria. The reference ores (quartz) sample was also sourced from that serves as overburden to the goldmine. The test ore and the reference ore were characterized using Energy Dispersed X-ray fluorescence spectrometer. 500 grams of gold ore and quartz were sampled and prepared by crushing and grinding to 100% passing 710µm sieve; 100 grams of prepared ores were charged into array of sieve arranged in √2 i.e from 500 µm to-45 µm. Set of sieves were mounted on automated sieve shaker and was operated for 20 minutes. The work index of reference ore was used to calculate the work index of the test ore using Gaudin Schuman expression to obtain a work index of 11.92kwh/ton for test ore. This work index value obtained for Iperindo gold ore (test ore) lies favorably within the work index of 8-16.5kwh/ton for gold ore sighted in the literature.

This paper provides chemical and mineralogical studies on Gold-bearing rock ore. The samples used was sourced from Iperindo at Ilesha Local Government Area of Osun state, Nigeria. 500g of the ore was weighed using digital weighing balance. The samples were crushed and ground until 80% passing of 75 µm sieve. The ground ore was blended homogeneously before the analysis while for the ore microscopic study, true fraction representative gold-bearing rock samples were prepared as polished mounts and characterized using Scanning Electron Microscope-Energy Dispersive X-ray (SEM/EDX). X-ray Fluorescence (XRF) was used to determine the chemical composition while identification of the associate mineral phase was done using X-ray Diffraction (XRD) technique. From the optical microscopy and SEM/EDX study, the gold grain was found embedded in the quartz and spotted interlocked in feldspar within a microscopic size level while a fracture type of surface morphology was observed which shows a protuberant quartz-feldspar veins texture. XRD shows the mineral phases of quartz, dolomite, sylvite, annite. The traces of K, Ba and Rb, in this compound shows that the ore is a typical mesothermal gold deposit. Hence, the gold is finely disseminated on the silicate mineral and this characteristic is unsuitable to be processed by physical separation as the microscopic gold will tend to be lost during processing. However, a sustainable processing method such as froth flotation can be proposed to overcome this problem.

The research investigates the liberation size of composite particles in Iperindo lode deposit at Ilesha goldfield in Osun state, Nigeria. The sample of the gold ore was sourced from Iperindo and 3 kilograms of gold ore was prepared by crushing and grinding to 100% passing 710µm sieve. 300 grams of the prepared ore was charged into set of sieves arranged in √2 i.e from 500 µm to-45 µm mounted on automated sieve shaker and operated for 20 minutes. Atomic Absorption Spectrometry (AAS) and X-ray Fluorescence (XRF) were used to determine the elemental and chemical composition of the ore. The chemical analysis of the crude sample via X-ray Fluorescence Spectrometry (XRF) revealed that the crude sample contain high content of Fe, Ti, Mn and K. The traces of K, Ba and Rb, shows that composite particles in Iperindo gold-bearing rock ore was formed as a result of hydrothermal alteration and the characterization of the sieve fractions by Atomic Absorption specteometey shows-63µm +45µm has the highest gold content when compare to other seive fraction. This indicates that the optimum liberation size of gold in Iperindo gold-bearing rock is 45µm. Processing of gold, which is economical viable from the ore deposit using froth flotation is desirable. Hence, efficient flotation of the mineral particle at the optimum liberation size of 45µm which lies favorably within the range of 10-150µm sighted from literature, will lead to good recovery of the gold particle.