Extraction and separation of gold (I) cyanide in polyethylene glycol-based aqueous biphasic systems

The extraction of gold (I) cyanide in polyethylene glycol-based aqueous biphasic systems has been investigated. Almost all of gold (I) cyanide (> 96%) was transferred from salt-rich phase into the polyethylene glycol (PEG)-rich phase without addition of any extractant. No significant influence of solution pH on gold (I) cyanide extraction was observed. The aqueous biphasic systems have high capability of extraction. The gold (I) cyanide in the PEG-rich phase can be easily reduced by addition of zinc. The PEG-rich phase could be reused for extraction of gold (I) cyanide without decrease of extraction capability. The PEG/salt aqueous biphasic systems may provide a potential new technique for gold separation from cyanide solutions because all components of systems are virtually nontoxic and nonflammable. (C) 2001 Elsevier Science B.V. All rights reserved.Metallurgy & Metallurgical EngineeringSCI(E)EI28ARTICLE141-466