Three‐Phase Extraction Study in the Cyanex923‐n‐Heptane/HNO₃ System

Abstract

The present paper reports a study of the extraction of HNO₃ with Cyanex923 (C923)‐n‐heptane. A third phase appears at different aqueous HNO₃ concentrations for various initial C923 concentrations. Data analysis indicates that almost all of HNO₃ and H₂O are extracted into the middle phase. More HNO₃ and water at a fixed ratio are solubilized in the reverse micelles or microemulsion in the third phase, which leads to a sharp increase of their concentration. The effect of temperature on the phase behavior of the three‐phase system has also been investigated.

Keywords:

• Extraction
• Three‐phase
• Cyanex923
• HNO₃

Acknowledgments

The authors wish to thank Dr. Donato Nucciarone of Cytec Canada for supplying C923. This project is supported by State Key Project of Fundamental Research (G1998061301), National “863” Project (2002AA647070), and the National Natural Science Foundation of China (29771028, 29801004).