Experimental and molecular modeling investigation on adsorption of gold cyanide complex onto the iron oxide and hydroxide minerals

[Display omitted] •Goethite had the highest preg-robbing potential among three studied minerals.•Fe site of FeO(OH) (010) surface was the most stable adsorption position.•The strongest binding on the FeO(OH) (010) surface is due to higher stabilization.•P-orbital energy level had higher influence on the adsorption of Au(CN)2-.•Molecular modeling confirmed the results of experimental tests. Complex and refractory gold ores contain high amount of iron oxide and hydroxide minerals, potential adsorbents of gold through preg-robbing phenomenon. In this study, density functional theory (DFT) approach was used to investigate the adsorption of Au(CN)2- complex on hematite, magnetite, and goethite surfaces. The most stable adsorption occurred for goethite when the Au(CN)2- complex was adsorbed from the Au atom along the y axis on the Fe site and the interaction energy was the highest. The following trend was obtained for the preg-robbing potential, which is in good agreement with experiments carried out on synthetic minerals: Goethite > Hematite > Magnetite.