Extraction of copper from bacterial leach liquor of a low grade chalcopyrite test heap using LIX 984N-C

Abstract

Low grade copper ore (ball mill spillage) obtained from Malanjkhand Copper Mine was processed through heap bioleaching at pilot scale. Bioleach liquor (Pregnant Leach Solution) from the heap contains (g/L of) Cu (II) 0.45, Fe (III) 0.838, Zn (II) 0.006, Ni (II) 0.0014, Mn (II) 0.011 and Pb (IV) 0.004. Solvent extraction of copper from Pregnant Leach Solution was carried out using LIX 984N-C. Effect of different operational factors such as equilibrium pH (pHe), extractant concentration, strip solution concentration, phase ratio was examined to optimize the condition for selective and quantitative extraction of copper. Based on the results of extraction as well as stripping isotherm, a 6-cycle counter current simulation study (CCS) was conducted for the conformational study. The extraction of copper was quantitative in 2-stages using 1.5% (v/v) LIX 984N-C at A: O ratio of 1:2 and pHe 1.85. The CCS condition (two stages, phase ratio A:O=1:4) obtained from the stripping isotherm study, further attributes to the enrichment (4 folds) of copper concentration in the strip solution.