Solvent extraction of trace gold(I) in alkaline cyanide solution using CTAB/TBP system

The solvent extraction of trace gold(I) in alkaline cyanide solution by CTAB/TBP system was investigated using a new kind of extraction equipment. Various parameters, such as the effect of addition of CTAB aqueous phase, the quantity of TBP, the concentration of NaCl were studied. The results demonstrate that the addition of CTAB in aqueous phase can enhance the gold (I) extraction rate of TBP sharply. Though it has little effect on the gold (I) extraction percentage, the concentration of NaCl and the quantity of TBP can reduce the degree of emulsification. The extraction of 50 L alkaline cyanide solutions in three extraction columns shows that the extraction percentage is more than 95%, and the gold mass concentration of raffinate is less than 0.5×10~(-6) in the all extraction process. Gold (I) stripping from gold loaded organic phase by KSCN was also studied. About 93% gold (I) in organic phase could be stripped into aqueous phase when the concentration of KSCN reached 3 mol/L.