Characterization of the gold complex adsorbed on activated carbon from chloride, cyanide and thiourea solutions

CIM Bulletin, Vol. 86, No. 967, 1993

J.R. Brown, Energy Research Laboratories CANMET-EMR, Ottawa, Ontario G. Deschenes, Mineral Sciences Laboratories CANMET-EMR, Ottawa, Ontario

X-ray Photoelectron Spectroscopy (XPS), X-ray Diffraction (XRD) and Electron Probe Micro-Analysis (EPMA) were used to characterize chemically the gold complex adsorbed on activated carbon from a solution containing 102 mg/L Au and 0.5 g/L thiourea. This paper also considers the gold chloride and the gold cyanide systems. The results indicate gold is adsorbed on activated carbon from the thiourea solution as the gold (I) thiourea complex, i.e. Au[CS (NH2)2]2+. Other gold species such as metallic gold were not detected on the carbon support. These results also suggest the elution of the gold (I) thiourea complex can be performed with high recovery.
Keywords: Mineral processing, Gold complex characterization, X-ray photoelectron spectroscopy, Surface chemistry, Thiourea.