METHOD OF RECOVERING COPPER AND PRECIOUS METALS

• Main Authors: HIETALA KARI, KARONEN JANNE, SINISALO PIA
• Format: Patent
• Language: English
• Published: 31.12.2015
• Subjects: CHEMISTRY; FERROUS OR NON-FERROUS ALLOYS; METALLURGY; PRETREATMENT OF RAW MATERIALS; PRODUCTION AND REFINING OF METALS; TREATMENT OF ALLOYS OR NON-FERROUS METALS

Provided is a method of recovering copper and one or more precious metals comprising leaching copper-bearing ore and/or concentrate under atmospheric or slightly pressurized conditions at a temperature below the boiling point of the leach solution in a sulfuric acidic solution in the presence of one or more alkali metal or alkali earth metal halides, whereby the total halide concentration is from 30 to 115 g/L, to dissolve copper and to obtain a leaching liquor comprising copper, sulfur species, and halides in solution. The leaching liquor is then subjected to a solid-liquid separation after which a first aqueous pregnant leach solution and a copper depleted leaching residue are obtained. Copper is purified by solvent extraction from the first aqueous pregnant leach solution to obtain a first copper-containing loaded organic solution and a first aqueous raffinate. The copper containing loaded organic solution is stripped and copper is recovered.