Abstract: Separation and recovery of divalent nickel and cobalt ions from a bioleaching solution were studied using a synergistic extraction system with P507and Cyanex272. The effects of initial pH value, volumetric ratio of P507 to Cyanex272 (P/C) in organic phase, and ratio of aqueous to organic phase (A/O) on the separation of divalent cobalt and nickel ions were studied. The results showed that the optimal conditions for the separation were: the saponification rate of organic phase 50% and saponification time 30 min, the organic phase composed of 10% [P507:Cyanex272 at 3:2 (volume ratio)], 85% sulphonated kerosene and 5% TBP, A/O 3 to 1 and initial pH value 2.5. In these conditions, the extraction rate of divalent cobalt ion is 92.96%. At the A/O of 2 to 3, turbulence intensity of 225 r/min, time of 4 min, 98.68% of stripping rate of divalent cobalt ion could be obtained with 200 g/L of H2SO4 as the stripping agent, the separation of divalent nickel and cobalt ions was realized under the low initial pH value.

Key words: cobalt-nickel separation, P507, Cyanex272, synergistic extraction

摘要： 采用P507与Cyanex272协同萃取分离回收浸出液中的Ni2+, Co2+，考察了初始pH值、有机相复配比(P/C)和水油相比(A/O)的影响. 结果表明，协萃优化条件为：有机相皂化率50%，皂化时间30 min；有机相组成为10%复配萃取剂[P507:Cyanex272为3:2(j)]+85%磺化煤油+5% TBP；相比为3:1，水相pH值为2.5. 在此条件下，Co2+的一级萃取率为92.96%. 利用200 g/L硫酸反萃负载有机相，在相比2:3、振荡强度225 r/min、时间4 min的条件下，Co2+的反萃率为98.68%，实现了低pH值下Ni2+和Co2+的萃取分离.

关键词: 钴镍分离, P507, Cyanex272, 协同萃取