Adsorption of Complex Ion Au(CN)2 on a Sulfur-Impregnated Activated Carbon in Aqueous Solutions,

Kardia Ramírez Muñiz, Shaoxian Song, Selene Berber Mendoza and Shitang Tong
Journal of Colloid and Interface Science, 349, 602-606., 2010.


The adsorption of the gold–cyanide complex ion (AuðCNÞ2 ) on sulfur-impregnated activated carbon in aqueous solution has been studied in order to find a better adsorbent for the gold cyanidation process for extracting gold from ores. This study was performed using sulfur-impregnated activated carbon (SIAC 8.0) made from high-sulfur petroleum coke and an artificial aqueous solution of AuðCNÞ2 . The experimen- CNÞ2 strongly adsorbed onto the SIAC 8.0, leading the gold adsorption capacity of the SIAC 8.0 to be 2.25 that on conventional activated carbon. It has been also found that Sulfur-impregnated activated carbon Chemical adsorption the adsorption fit the Langmuir isotherm well, and the adsorption density of AuðCNÞ2 on the SIAC 8.0 Gold–cyanide complex ion in aqueous solution increased with increasing temperature, suggesting chemical adsorption. The chem- ical adsorption might be attributed to the formation of S–Au–CN on SIAC 8.0 surfaces through the cova- lent bond between the gold atom of the ion and the sulfur in the molecular structure of the SIAC 8.0. In addition, the desorption test has demonstrated that the majority of the adsorption was irreversible, which depended on the density of the adsorption sites on the SIAC.