P_(204)-H_3cit-NdCl_3体系负载有机反萃取的研究

非皂化P204-H3cit-NdCl3体系萃取分离稀土的方法有效地解决了传统萃取分离体系下,稀土工业生产存在皂化废水中氨氮含量高污染水资源等问题,但该体系反萃取的酸度过高而限制了该方法的进一步应用.通过单级和错流反萃取研究了反萃液酸度、反萃温度、反萃时间和反萃级数对反萃取率的影响,并以此为基础,进一步研究了0.6 mol/L低酸度六级逆流反萃取.实验结果表明:与单级及错流反萃取相比,六级逆流反萃率可达到100%,酸利用率为50%左右,明显减少了酸耗,而且反萃余液酸度为0.3 mol/L左右,达到了现有稀土萃取分离的工业要求.该研究为非皂化P204-H3cit-NdCl3体系萃取稀土元素的应用提...

Studies on Re-extraction of Organics Loaded with a P204-H3cit-NdCl3 System

The unsaponified P204-H3cit-NdCl3 extraction system can effectively solve the pollution problem of the saponification waste water in traditional Nd extraction separation systems.But further application of this method is limited by high acidity of the re-extraction process in this system.The effect on reextraction ratio of re-extraction acidity,temperature,times,and stage was investigated through single-level re-extraction and cross-flow re-extractions. With these results as a foundation,further studies were conducted for countercurrent re-extraction with low acidity of 0.6 mol/L and six stages.Results indicated that countercurrent re-extraction rate reached 100% compared to singlestage and cross-flow re-extraction,and acid consumption was significantly reduced to 50%.Acidity remaining after re-extraction was 0.3 mol/L,and this meets the industrical requirements of the rare earth extraction.These methods of unsaponified P204-H3cit-NdCl3 extraction provided a certain basis for the application of rare earth elements.