Sorption of Dicyanoaurate Anions by Novel Resins Containing N,N′ substituted Diamides of Malonic Acid

Abstract

Two novel ion-exchange/coordinating resins have been synthesized and used in the sorption of dicyanoaurate anions, Au(CN)⁻ ₂, from aqueous solution from their mixtures with Fe(III) cyano complexes, Ag(I) cyano complexes, Zn(II) cyano complexes, Fe(II) cyano complexes, Cu(II) cyano complexes, and from solutions containing all of the above species. It has been found that Resin 1 containing the N,N′-substituted amide of malonic acid with terminal guanidyl groups is able to remove ca. 10 mg Au/g, and Resin 2 containing the N,N′-substituted amide of malonic acid with terminal imidazole groups removes ca. 13 mg Au/g from the above solutions when there is an initial concentration of 5.08 mg Au/dm³. Resin 1 is selective toward gold over all metals but Fe(II). Resin 2 is more selective, and when sorption is carried out from the solution formulated with all the metals displays the following selectivity coefficients: of gold over Fe(II) + Fe(III), +∞; of gold over Ag(I), +∞; of gold over Zn(II), 3.79; and of gold over Cu(II), 2.81.

ACKNOWLEDGEMENT

Partial support of this work from the State Committee for Scientific Research through Grant 3T09B 093 11 is gratefully acknowledged.