Lix984N的降解行为研究

The Study on Degradation of Lix984N

Lix984N与酸性浸出液和反萃剂长期接触 ,会通过贝克曼重排、水解、氧化、磺化等机理逐渐降解 ,其中Lix84有效成分和壬基酚经长期循环使用后完全降解 ,它们的化学稳定性比Lix860N差。降解产生含羰基、羧基、羟基及酰胺等基团的极性两亲分子。循环有机相中萃取剂有效成分的含量明显低于杂质和降解产物的量 ,GC -MS分析三者的相对含量为Lix860N∶稠环芳烃∶降解产物=1∶2 .1∶3 .2。萃取剂降解是萃取性能降低、分相性能恶化、界面乳化加重的内在原因。

Being long term touched with the acidic aqueous feed and strip reagent, Lix984N can be degraded gradually by such reaction mechanisms as Beckmann rearrange, hydrolyzing, oxidizing and sulfonating. The effective compositions of Lix84 and nonylphenol are degraded almost completely after long term circulation, so they are less stable than the effective compositions of Lix860N. Many kinds of amphiphiles containing such hydrophilic group as carbonyl, carboxyl, hydroxyl or acylamine are produced during the reagent degradations. The content of effective compositions of Lix984N is far lower than that of dense-aromatic impurities originated from diluent and the reagent degradation productions in the long term circulated organic phase. The relative ratio of these three proportions is 1∶2.1∶3.2. The degradation of Lix984N results in deteriorated solvent extraction and disengagement performance and more serious interfacial emulsion.