The solvent extraction of gold(I) from aurocyanide solutions by means of various reagents: amines (Primene JMT, Amberlite LA2, Alamine 336), solvation extractants (TBP, Cyanex 921, DMPL) and mixtures of both is reported. Different variables that could affect the systems were evaluated; on the basis of the numerical treatment of experimental data, the stoichiometries of the extracted species (generally represented by HAu(CN)2·R·Lq, R being the amine, L the solvation extractant and q depending either of the amine and/or the solvation reagent) are proposed. The permeation of Au(I) through a supported liquid membrane impregnated with various of the extractants has been investigated. High selectivity in the separation, through supported liquid membrane, of Au(I) against different metal–cyano complexes (Ag(CN)2−, Cu(CN)43−, Zn(CN)42−, Fe(CN)63−) is achieved.

This work was supported by CICYT QUI 96-1025. and Comissionat per Universitats i Recerca SGR98-00082.. Authors gratefully acknowledge to Rohm and Haas Primene JMT, Amberlite LA2., Henkel Alamine 336, LIX 79., CYTEC Cyanex 921. and Bayer Leverkusen DMPL. for gift samples of their reagents. Also to the CSIC for support.

Peer reviewed