Potentiometric studies on the adsorption of Au(CN)2 and Ag(CN)2 onto activated carbon

Tsuchida, N. and Muir, D.M. (1986) Potentiometric studies on the adsorption of Au(CN)2 and Ag(CN)2 onto activated carbon. Metallurgical Transactions B, 17 (3). pp. 523-528.

Abstract

The adsorption of Au(CN) 2 − and Ag(CN) 2 − onto activated carbon has been correlated with potential measurements of carbon. It is proposed that Au(CN) 2 − , Ag(CN) 2 − , and CN− are adsorbed on carbon by both an ion exchange mechanism and an oxidative reaction which leads to a decrease in carbon potential. The potential of carbon decreased according to the degree of anion adsorption in the order Au(CN) 2 − > Ag(CN) 2 − > CN− > I− > Cl−. Adsorption of anions is accompanied by release of OH− ion which raises the solution pH and decreases the carbon potential. The potential of carbon in contact with solutions containing KAu(CN)2, KAg(CN)2, or KCN is much more negative than that in contact with chloride solution at the same pH. The results indicate that cyanide is oxidized on the carbon surface by oxygen or by reducible functional groups such as quinone.

Item Type:	Journal Article
Murdoch Affiliation(s):	School of Mathematical and Physical Sciences
Publisher:	ASM International
URI:	http://researchrepository.murdoch.edu.au/id/eprint/20575

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