Elkem As

Other

Gunnar H Boe

Tore Danielssen

Einar Andersen

Arne Bjune

Copper content in sulphide-containing materials such as ores or concentrates is extracted by leaching the material by means of a leaching solution containing iron (III) chloride and copper (II) chloride, the leaching process being regulated in order to keep the red-ox potential in the leach solution between 430 mV and 460 mV, whereby iron (III) chloride is reduced to iron (II) chloride while copper (II) chloride is kept in the bivalent state. The copper content in the ore or concentrate is thereby leached as copper (II) chloride. Copper (II) chloride is thereafter extracted from the pregnant leach solution by contacting the solution with an organic complex-ion forming extractant which extraction properties are dependent on the chloride concentration.

Hydrometallurgical method of extraction of copper from

Selective extraction of zinc from chloride solutions which contain iron, copper and zinc, where the zinc is extracted in organic phase by means of tri-n-butylphosphate in an organic solvent. The extraction is carried out on chloride solutions in which the lead contents is possibly lowered and where the copper contents is maximum 50 grams per liter higher copper concentration being reduced for instance by electrolysis in diaphragm cell. The zinc containing organic phase is washed, and zinc back-extracted and conducted to a diaphragm cell for electrolysis of zinc, the used electrolyte being returned to the back-extraction step. The raffinate from the zinc extraction is used for repeated leaching of metals after preceding reoxidation.

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Kristiansand, Norway

Gunnar H Boe