新型含氧醚键吡啶萃取剂在氨溶液中的萃取与反萃性能研究

为了解决目前工业萃取剂对Cu²⁺选择性差以及对Zn²⁺萃取能力差的问题, 合成了一种新型萃取剂MPPE, 并考察了由MPPE组成的有机相在氨溶液体系中对Cu²⁺、Ni²⁺、Co²⁺和Zn²⁺的萃取与反萃性能。结果表明, 在萃取剂MPPE浓度0.06 mol/L、总铵浓度1.2 mol/L、相比(O/A)1/1、混合时间5 min、pHeq=6.44条件下, Cu²⁺萃取率达到95.8％, 而Ni²⁺、Co²⁺和Zn²⁺萃取率分别为2.8%、3.7%和8.1%, 分离系数β_Cu/Ni、β_Cu/Co和β_Cu/Zn分别高达666.20、508.42和219.55。而当其他萃取条件不变, 将平衡pH值调为8.23时, β_Zn/Ni和β_Zn/Co都达最大值, 分别为137.90和74.20。在硫酸浓度1 mol/L、反萃时间6 min以及反萃相比1/1条件下对铜和锌的负载有机相进行反萃, 锌和铜离子反萃率均在97%以上。

Extraction and Stripping Performance of a New Type of Oxygenated Ether Bond Pyridine Extractant in Ammonia Solution

In view of the problem that industrial extractants have the poor selectivity for Cu²⁺ and poor extraction ability for Zn²⁺, a new type of extractant of MPPE has been synthesized, and the extraction and stripping efficiencies of Cu²⁺, Ni²⁺, Co²⁺ and Zn²⁺ by the organic phase composed of MPPE in ammonia solution system were investigated. The results show that after mixing for 5 min, with 0.1 mol/L of MPPE and 1.2 mol/L of c(NH₃)_T, with an O/A ratio at 1/1 and equilibrium pH of 6.44, the extraction efficiency of Cu²⁺ reached 95.8%, but the extraction rates of Ni²⁺, Co²⁺ and Zn²⁺ were 2.8%, 3.7% and 8.1%, respectively. The separation coefficients of β_Cu/Ni, β_Cu/Co and β_Cu/Zn were as high as 666.20, 508.42 and 219.55, respectively. Furthermore, β_Zn/Ni and β_Zn/Co maximumly reached 137.90 and 74.20 respectively at equilibrium pH of 8.23 with the other extraction conditions remaining unchanged. And the experiment of stripping for 6 min with 1 mol/L of sulfuric acid at an O/A ratio of 1/1 showed that the stripping efficiencies of zinc and copper were all above 97%.