Comparison on Separation of Low-Content Nickel and Cobalt in Bioleaching Solution in Different Extraction System

Abstract

As an effective method for increase extraction efficiency and selectivity,synergistic extraction has been studied for many years because the theoretical and applicative importance. Using synergistic effect of two extractants, distribution ratios of their mixture can be obviously enhanced than those of their individual contributions. Separation of nickel and cobalt for bioleaching solution were studied using a synergistic extraction system with P507 andCyanex272. The test results indicate that the system has better extraction effect. Contrasts the separation effect on nickel and cobalt using three extraction systems of P507, Cyanex272, P507-Cyanex272. Identified during the initial pH value of 1.5-2.2, balance pH value under the condition of 4.0-5.0,synergistic extraction system of P507-Cyanex272 have a good separation effect of nickel and cobalt. The extraction kinetics was investigated using a constant interfacial cell with laminar flow. The effects of temperature, extractant and cobalt concentration were studied. Co extraction rate was compared in the different extraction systems of individual P507 and synergistic P507-Cyanex272 .The results indicated that the extraction apparent action energy in synergistic system was lower than that of signal P507.The separation factor of nickel and cobalt was increased in synergistic system.