Autoclave oxidation leaching of sulfide materials containing copper, nickel and/or cobalt
AssigneeThe International Nickel Company, Inc.
InventorsGrigori S. Victorovich, Norman C. Nissen, Kohur N. Subramanian
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Abstract
A process is provided for treating a matte for selective extraction of nonferrous metals using a single stage oxidative pressure leach wherein leaching is carried out in a continuous manner and relatively mild conditions on an aqueous slurry of the matte having a specific sulfur adjustment, having copper present in the aqueous phase, and having a final pH of less than .about.4 but not less than .about.3.
Claims24
A process for treating a finely ground matte containing copper and sulfur values and at least one of the metal values nickel and cobalt, and which may also contain iron values, to effect selective extraction of nickel and/or cobalt from copper and, if present, iron values, comprising:
- forming an aqueous slurry comprising ground matte, said slurry having a sulfur content, apart from elemental sulfur, substantially equivalent on a molar basis to the nickel and cobalt plus about 35% to about 70% of the copper in said slurry;
- subjecting said slurry to a single stage oxidative pressure leach in a continuous manner in the presence of copper in the aqueous phase of the slurry for a period of time necessary to convert substantially all of the sulfidic sulfur in the slurry to the sulfate form, and allowing the pH of the slurry to drop to a level of below about 4 but not below about 3;
- separating the leach liquor from the leach residue;
- and thereby obtaining a leach liquor containing a preponderant amount of the nickel and cobalt values and a minor amount of the copper values and a copper sulfate hydrate containing leach residue containing a preponderant amount of the copper and substantially all the iron values.
A process for treating a finely ground matte containing copper and sulfur values and at least one of the metal values nickel and cobalt, and which may also contain iron values, to effect separation of nickel and/or cobalt from copper, if present, iron values, comprising:
- forming an aqueous slurry comprising ground matte, said slurry having a sulfur content, apart from elemental sulfur, equivalent on a molar basis to the nickel and cobalt plus about 35% to about 70% of the copper in said slurry;
- subjecting said slurry to a single stage oxidative pressure leach in a continuous manner at an elevated temperature up to about 130.degree. C. and a pressure of at least about 0.25 MPa in the presence of at least about 0.5 gram per liter of copper in the aqueous phase of the slurry for a period of time necessary to convert substantially all the sulfidic sulfur in the slurry to the sulfate form and allowing the pH of the slurry to drop to a level of below about 4 but not less than about 3, separating the leach liquor from the leach residue, and thereby obtaining a leach liquor containing a preponderant amount of the nickel and cobalt values and a minor amount of the copper values and a copper sulfate hydrate containing leach residue containing a preponderant amount of the copper and substantially all the iron values.
A process for treating a finely ground matte containing copper and sulfur values and at least one of the metal values nickel and cobalt, and which may also contain iron values, to effect separation of nickel and/or cobalt from copper and, if present, iron values, comprising:
- forming an aqueous slurry comprising ground matte, said slurry having a sulfur content, apart from elemental sulfur, equivalent on a molar basis to the nickel and cobalt plus about 35% to about 70% of the copper in said slurry;
- subjecting said slurry to a single stage oxidative pressure leach in a continuous manner at an elevated temperature up to about 130.degree. C. and a pressure of at least about 0.25 MPa in the presence of at least about 0.5 gram per liter of copper in the aqueous phase of the slurry for a period of time necessary to convert substantially all the sulfidic sulfur in the slurry to the sulfate form and allowing the pH of the slurry to drop to a level of below about 4 but not less than about 3;
- separating the leach liquor from the leach residue, and thereby obtaining a leach liquor containing a preponderant amount of the nickel and cobalt values and a minor amount of the copper values and a copper sulfate hydrate containing leach residue containing a preponderant amount of the copper and substantially all the iron values;
- treating the leach liquor with ground fresh matte under oxidizing conditions at a temperature of about 60.degree. C. to about 85.degree. C. to precipitate copper from the leach liquor;
- separating the copper-depleted leach liquor from the solids containing the precipitated copper, and recovering at least one of the metals nickel or cobalt from the copper-depleted leach liquor.
Dependencies are inferred from the claim text.