Selective extraction of gold and platinum in water using ionic liquids. A simple two-step extraction process.

We report an all-ionic liquid process for the separation of tetrachloroaurate and hexachloroplatinate complexes. In a first step, gold is removed from water by liquid-liquid extraction with a hydrophobic ionic liquid, 1,2-dimethyl-3-octylimidazolium bis(trifluoromethylsulfonyl)imide. Platinum is subsequently extracted from the solution in the presence of KSCN using 1-methyl-3-octylimidazolium bis(trifluoromethylsulfonyl)imide.