Investigation of Copper Recovery rate from Copper Oxide Ore Occurring as Coarse Grains Locked in a Porphyritic Fine Grain Alumina and Silica

Abstract

An investigation was carried out on a high grade copper oxide ore to determine the optimum recovery rate of copper from the pregnant leached solution obtained from leaching the ore in a sulfuric acid lixiviant. The copper oxide ore occur in coarse grains locked in a porphyritic fine grain alumina and silica. 800 g of copper oxide ore was obtained at the deposit; the samples were chemically and mineralogically analyzed. The analysis shows that the copper oxide ore contain 19.52 % copper extraction. The ore samples were crushed to sizes within 5 cm and 12 cm. The crushed samples were then grinded to a mesh size of -150 µm. This size was used to conduct the leaching process and sulfuric acid was used as the lixiviant. Parameters varied in this study include: the concentration of acid, temperature and time. The pregnant leach solution obtained was analyzed and the results showed an increase in the % recovery of copper as the molar concentration of H2SO4 increases from 0.25M to 1M and the % copper extraction decreases as the acid concentration increases from 1 M to 3 M. Higher copper recovery of 32.13 % was observed at elevated temperature of up to 80oC. These findings suggest the possibility of effectively producing copper from the Pingel-Bauchi Deposit through hydrometallurgical extraction process; optimum recovery can be obtained at an elevated temperature using acid concentration of 1 M.