GOLD SOLVENT EXTRACTION

• Main Authors: HAAPALAINEN, Mika, KARONEN, Janne
• Format: Patent
• Language: English
• Published: 20.02.2017
• Subjects: CHEMISTRY; FERROUS OR NON-FERROUS ALLOYS; METALLURGY; PRETREATMENT OF RAW MATERIALS; PRODUCTION AND REFINING OF METALS; TREATMENT OF ALLOYS OR NON-FERROUS METALS

The present invention provides a method of extracting gold from pregnant leach solution (PLS) obtained from leaching of gold, comprising the steps of: (a) extracting the PLS with an organic extractant comprising an organic diester and an organic long-chain alcohol to obtain a first organic phase comprising gold; (b) stripping gold from the first organic phase with a first water to obtain a first aqueous raffinate comprising gold and a first depleted organic phase; (c) adding HCl and NaCl into the first aqueous raffinate to increase its acid content to at least 8 g/L and chloride content to at least 30 g/L to obtain a first aqueous solution comprising gold; (d) extracting the first aqueous solution with an organic extractant comprising an organic diester and an organic long-chain alcohol to obtain a second organic phase comprising gold; (e) stripping gold from the second organic phase with a second water solution to obtain a second aqueous raffinate comprising gold and a second depleted organic phase; (f) optionally repeating steps (c) to (e) one or more times to obtain a final aqueous raffinate comprising gold.