Solvent Extraction of Au(III) by the Chloride Salt of the Amine Alamine 304 and Its Application to a Solid Supported Liquid Membrane System

Abstract

The extraction of Au(III) by the chloride salt of the amine Alamine 304 (R₃NH⁺Cl⁻) in xylene from hydrochloric acid solutions has been investigated. The analysis of metal distribution data by numerical calculations suggested the formation of the species R₃NH⁺AuCl₄ ⁻ in the organic phase with formation constant log K _ext = 5.44. The results obtained on Au(III) distribution have been implemented in a solid‐supported liquid membrane system, where in NaSCN solutions were found to be the most effective to strip the metal from the organic solution. Influence of membrane composition, metal concentration on gold transport, and the selectivity of the system have also been studied.

Keywords:

• Solvent extraction
• Membrane transport
• Gold(III)
• Alamine 304

Acknowledgments

This work has been carried out under the support of CSIC (Spain). Technical assistance by Mr. Bascones and Mr. López is also thanked.