EFFECTIVENESS OF GRAVITY SEPARATION TECHNIQUES FOR THE BENEFICIATION OF DERU SILVER-GOLD ORE, BAUCHI STATE

The characterization of Deru gold-silver was carried out in the course of this research work.The gold-silver deposit is located in Deru village, Ningi Local Government Area, Bauchi State.Samples were taken from four pits at depths ranging from 12m to18m.Each of the ore samples were divided into four parts and used for the various tests.A batch of each of the three samples were mixed together, crushed, and prepared through extensive coning and quartering for tests including: X-ray fluorescence (XRF), Inductively Coupled Plasma (ICP-AES), X-ray diffraction (XRD) and Scanning Electron Microscope (SEM/EDS).The bulk density of the ore was also determined.The results of the chemical analysis revealed that the crushed sample contained 12.2g/t Au, 256g/t Ag, 29.09% Si, 40% Fe, 3.45% Pb, and 3.15% Zn on the average for XRF and 11.2g/t Au, 266g/t Ag, 34.09% Si, 45.47% Fe, 3.45% Pb, 3.15% Zn and 3.01% Al on the average for ICP-AES.Mineralogical analysis carried with SEM showed that the ore contains quartz, hematite, silver, garnet and gold in significant quantities and thus represent the major minerals.The SEM/EDS analysis results revealed the interlocking nature of the minerals within the ore matrix.It is observed that the minerals are separated by quartz grain boundaries which may facilitate intergranular liberation and produce high percentage of free particles during comminution.Particle size analysis revealed that the various mineral phases are evenly distributed in all the various sieve size fractions (+710 µm to -45 µm).The results obtained are compared with that of the literatures cited.Deru gold-silver deposit may be another potential source of silver-gold that can be extracted after beneficiation and supplied to smelting industries The beneficiation runs carried out with sieve size -355 µm + -250.