Recovery of Platinum and Palladium from Chloride Solutions by a Thiodiglycolamide Derivative
Recovery of Platinum and Palladium from Chloride Solutions by a Thiodiglycolamide Derivative
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用硫代二甘醇酰胺衍生物从氯化物溶液中回收铂和钯
DOI：
10.1080/07366299.2013.810969
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发表时间：
2014
影响因子：
2
通讯作者：
C. Nogueira
中科院分区：
文献类型：
--
作者：
A. Paiva;G. Carvalho;M. C. Costa;A. da Costa;C. Nogueira
研究了N，N‘-二甲基-N，N’-二环己基硫代二乙醇酰胺(DMDCHTDGA)在1，2-二氯乙烷(1，2-DCE)中对铂(IV)和钯(II)的液液萃取。铂(IV)可从5M以上的盐酸中有效地提取(%E≥97%)，而Pd(II)可从1~8M的HCl溶液中定量回收。铂(IV)和钯(II)均能从负载的有机相中被成功地反萃，前者用1M的HCl溶液，后者用0.1M的硫脲在1M的HCl溶液中反萃。DMDCHTDGA对铂(IV)的最大负载量无法确定，但很高，因为萃取剂与铂(IV)的摩尔比已达到2~3。从连续的萃取-反萃循环中获得的数据表明，DMDCHTDGA对铂(IV)的回收具有良好的稳定性。用更环保的稀释剂取代1，2-DCE的尝试表明，通常情况下，铂(IV)的%E与之相当。研究酸度以及氯离子和DMDCHTDGA浓度的影响，可以提出萃取时形成的铂(IV)物种的组成。二元金属离子溶液的实验结果表明，通过顺序选择性反萃可以有效地从负载DMDCHTDGA的有机相中分离铂(IV)和钯(II)。
The liquid-liquid extraction of platinum(IV) and palladium(II) from hydrochloric acid media was carried out using N,N’-dimethyl-N,N’-dicyclohexylthiodiglycolamide (DMDCHTDGA) in 1,2-dichloroethane (1,2-DCE). Pt(IV) is efficiently extracted from 5 M HCl onwards (%E ≥ 97%), whereas Pd(II) is quantitatively recovered from 1 to 8 M HCl solutions. Both Pt(IV) and Pd(II) can be successfully stripped from the loaded organic phases, the former with a 1 M HCl solution, the latter with 0.1 M thiourea in 1 M HCl. The maximum loading capacity of DMDCHTDGA for Pt(IV) could not be determined but it is high, since molar ratios extractant:Pt(IV) within 2 and 3 have been achieved. Data obtained from successive extraction-stripping cycles suggest a good stability profile of DMDCHTDGA towards Pt(IV) recovery. Attempts to replace 1,2-DCE by more environmentally-friendly diluents showed, in general, comparable %E for Pt(IV). The study of the influence of acidity, as well as chloride ion and DMDCHTDGA concentrations, allows a proposal for the composition of the Pt(IV) species formed upon extraction. Results obtained with binary metal ion solutions point out that Pt(IV) and Pd(II) can be efficiently separated from DMDCHTDGA loaded organic phases through sequential selective stripping.