A SPECTROELECTROCHEMICAL STUDY OF CHEMISORPTION OF ETHYL XANTHATE ON GOLD

The species formed by the anodic oxidation of ethyl xanthate at gold e lectrodes has been investigated using an ex situ Fourier transform inf rared (FTIR) spectroscopic technique to distinguish between chemisorbe d ethyl xanthate and diethyl dixanthogen. Chemisorption of xanthate wa s found to commence about 0.15 V below the potential at which dixantho gen deposits and to reach a fractional surface coverage of about 0.2 a t the reversible value of the xanthate/dixanthogen couple. The coverag e increased in parallel with the anodic current arising from dixanthog en deposition. The significance of these findings on the mechanism of the flotation of gold with ethyl xanthate as collector is discussed.