Chloride assisted hydrometallurgical extraction of metal
AssigneeCominco Engineering Services Ltd.
InventorDavid L. Jones
Life of this patent
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Abstract
A process for the extraction of precious metals from a copper sulphide ore or concentrate, by treating a leach residue of the ore or concentrate, includes the steps of removing elemental sulphur from the leach residue to obtain a low sulphur residue and subjecting the low sulphur residue to an oxidative leach at elevated temperature and pressure to oxidize sulphur and precious metal compounds present in the low sulphur residue to produce a residue for the extraction of the precious metals therefrom.
Claims13
A method of preparing a copper sulphide ore or concentrate for the extraction of precious metals therefrom by treating a leach residue of the ore or concentrate, comprising the steps of:
- subjecting the leach residue to froth flotation to produce a sulphur rich flotation concentrate and a sulphur depleted flotation tail;
- subjecting the flotating concentrate to sulphur extraction with a sulphur extractant to produce a low sulphur residue;
- and
- subjecting the low elemental sulphur residue to an oxidative leach at elevated temperature and pressure to oxidize elemental sulphur and sulphide minerals present in the low sulphur residue to produce a residue for the extraction of the precious metals therefrom, wherein prior to the sulphur removal, the ore or concentrate is subjected to pressure oxidation at an elevated temperature and pressure in the presence of oxygen and an acidic halide solution to produce said leach residue.
A method of preparing a copper sulphide ore or concentrate for the extraction of precious metals therefrom, comprising the steps of:
- subjecting the ore or concentrate to pressure oxidation in the presence of oxygen and an acidic halide solution to obtain a resulting pressure oxidation slurry;
- and
- flashing the slurry to atmospheric pressure in a two-stage let-down in which the first stage is at a temperature of about the freezing point of elemental sulphur.
A method of preparing a copper sulphide ore or concentrate for the extraction of precious metals therefrom by treating a leach residue of the ore or concentrate, comprising the steps of:
- subjecting the leach residue to froth flotation to produce a sulphur rich flotation concentrate and a sulphur depleted flotation tail;
- subjecting the flotation tail to a liquid/solid separation to produce a first solid and a first liquid;
- subjecting the flotation concentrate to a liquid/solid separation to produce a second solid and a second liquid;
- subjecting the second solid to sulphur extraction with a sulphur extractant to produce a low sulphur residue;
- and
- subjecting said first solid and said low sulphur residue to an oxidative leach at elevated temperature and pressure to oxidize elemental sulphur and sulphide minerals present in the second solid and the low sulphur residue to produce a residue for the extraction of the precious metals therefrom.
Dependencies are inferred from the claim text.