Extraction Equilibrium of Zinc(II) and Cadmium(II) by Mixtures of Primary Amine N1923 and 2-Ethylhexyl Phosphonic Acid Di-2-Ethylhexyl Ester

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• 作者：Qiong Jia ; Lihua Bi ; and Qingkun Shang
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2003
• 出版时间：September 3, 2003
• 年：2003
• 卷：42
• 期：18
• 页码：4223 - 4227
• 全文大小：74K
• 年卷期：v.42,no.18(September 3, 2003)
• ISSN：1520-5045

文摘

The extraction of zinc(II) and cadmium(II) from chloride media by mixtures of primary amineN1923 and 2-ethylhexyl phosphonic acid di-2-ethylhexyl ester (EH/DEHP, B) has been studiedin the present paper. The mixtures have synergistic effects on zinc(II) at low levels of N1923but antagonistic effects at high N1923 levels. However, synergistic effects are observed for theextraction of cadmium(II) at any proportion of the extractants. Zinc(II) is extracted as (RNH₃Cl)₂·ZnCl₂·B, whereas cadmium(II) is extracted as (RNH₃Cl)_4.5·CdCl₂·B by the mixtures, insteadof (RNH₃Cl)₃·MCl₂ (M = Zn or Cd) by N1923 alone. Furthermore, the formation constants andthermodynamic functions were determined. The possibility of separating zinc(II) and cadmium(II) by these mixtures according to the synergistic or antagonistic effects was investigated.