ELECTRODIALYSIS OF SOLUTIONS OBTAINED BY ELUTION OF CYANIDE COMPLEXESFROM ANIONIC-EXCHANGE RESIN BY MEANS OF ACIDIC THIOUREA

Electrodialysis of copper-thiourea solutions is not recommended becaus e of the presence of formamidine disulphide which constitutes a poison for the cation exchange membrane. In this paper, it has been shown th at the electrodialysis of copper in a thiourea medium becomes possible when the solutions are obtained by means elution of cuprocyanides by thiourea. A new mechanism of both the elution of cuprocyanides and the ion transfer across the anion exchange membrane has bee formulated. T he process studied provided evidence for the recovery of acid used for the elution and its concentration in the cathode compartment as a pur e product which can be reused. Applications to leaching solutions of a n Algerian gold ore have also been performed. (C) 1997 Elsevier Scienc e B.V.