摘要
The distribution and competitive behaviors of phosphotungstic acid and ferric chloride in the TBP-HCl-H_(2)O system were investigated by controlling the extractant concentration and the solution environment.The results revealed that phosphotungstic acid exhibited a strong affinity for TBP with decreasing TBP concentration.Higher acidity significantly improved the W extraction efficiency with TBP,and the lower Cl^(-)concentration reduced the extraction efficiency of Fe.As the organic phase approached saturation point,phosphotungstic acid competitively displaced Fe to combine with TBP.The hydrogen bond structure(P=O·HO-P-W-O)between phosphotungstic acid and TBP was characterized by FT-IR,and the salting-out effect induced by FeCl_(3) was elucidated.In summary,high acidity is beneficial for exhaustive extraction of W,and an effective W/Fe separation can be achieved by reducing the concentrations of TBP and Cl^(-).
通过调控萃取剂浓度和溶液环境研究磷钨酸和氯化铁在TBP-HCl-H_(2)O体系中的分布和竞争行为。结果表明,随着TBP浓度的降低,TBP对磷钨酸的亲和力更强。在高酸度条件下W的萃取效率更高,而降低水相Cl^(-)浓度会抑制TBP对Fe的萃取。当有机相接近饱和负载时,磷钨酸能够竞争性地取代铁与TBP分子结合。FT-IR表征阐明了磷钨酸和TBP之间的氢键结合形式(P=O·HO—P—W—O),解释了FeCl_(3)诱导的盐析效应。因此,提高酸度有利于钨的深度萃取,而降低TBP和Cl^(-)浓度是实现W/Fe分离的有效措施。
基金
supported by the National key R&D Program of China(No.2022YFC2905105)
the National Natural Science Foundation of China(No.72088101)。
