METHOD TO IMPROVE RECOVERY OF GOLD FROM DOUBLE REFRACTORY GOLD ORES

• US 20090071295A1
• Filed: 09/11/2008
• Published: 03/19/2009
• Est. Priority Date: 09/17/2007
• Status: Active Grant

• Current Assignee: Barrick Gold Corporation
• Original Assignee: Barrick Gold Corporation
• Inventors: Kondos, Peter, Gorain, Barun
• Granted Patent: US 8,262,768 B2
• Time in Patent Office: Days
• US Class Current: 75/710
• CPC Class Codes: B03D 1/02 Froth-flotation processes
• CPC Class Codes: C22B 11/04 by wet processes extraction of metal compounds by leaching in organic solutions C22B3/16; treatment or purification of solutions by liquid-liquid extraction C22B3/26
• CPC Class Codes: C22B 11/08 by cyaniding
• CPC Class Codes: C22B 3/04 by leaching C22B3/18 takes precedence
• CPC Class Codes: C22B 3/24 by adsorption on solid substances, e.g. by extraction with solid resins
• CPC Class Codes: Y02P 10/20 Recycling

Abstract

The present invention is directed to a precious metal recovery process in which carbonaceous material, such as preg robbing carbon, is floated after sulfide oxidation to separate the carbonaceous material from the precious metal.

Claims

1. A method, comprising:

(a) providing a feed material comprising a precious metal, at least about 0.1 wt. % sulfide sulfur, and 0.3 to about 10 wt. % carbonaceous materials;

(b) oxidizing at least a portion of the sulfide sulfur in the feed material to provide an oxidized material, wherein at least most of the gold and/or silver and carbonaceous materials remain in the oxidized feed material;

(c) thereafter floating the oxidized feed material to separate the material into a first fraction comprising at least most of the gold and/or silver and a second fraction comprising at least about 25% of the carbonaceous materials in the feed material; and

(d) recovering the gold and/or silver from the first fraction.

2. The method of claim 1, further comprising:

(e) comminuting the oxidized material to remove, at least partially, an oxidative film on at least some particles of the oxidized material, wherein the comminuted and oxidized material is subjected to flotation in step (c).

3. The method of claim 2, further comprising:

(f) conditioning the comminuted and oxidized material by contacting the comminuted and oxidized material with a collector that renders the carbonaceous material more hydrophobic, wherein the conditioned comminuted and oxidized material is subjected to flotation in step (c).

4. The method of claim 3, wherein at least one of a sulfide depressant and carbonaceous material activator is contacted with the comminuted and oxidized material during conditioning.

5. The method of claim 3, further comprising:

(g) comminuting the second fraction to provide a comminuted second fraction;

(h) conditioning the comminuted second fraction by contacting the comminuted second fraction with the collector; and

(i) floating the comminuted second fraction to form a third fraction comprising most of the gold and/or silver in the second fraction and a fourth fraction comprising most of the carbonaceous material in the second fraction.

6. The method of claim 5, wherein gold and/or silver is recovered from the third fraction.

7. A method, comprising:

(a) providing a feed material comprising a precious metal, at least about 0.1 wt. % sulfide sulfur, and 0.3 to about 10 wt. % carbonaceous materials;

(b) pressure oxidizing at least a portion of the sulfide sulfur in the feed material to provide an oxidized material, wherein at least most of the gold and/or silver and carbonaceous materials remain in the oxidized feed material; and

(c) thereafter floating the oxidized feed material to separate the material into rougher tails comprising at least most of the gold and/or silver and a rougher concentrate comprising at least about 25 wt. % of the carbonaceous materials in the feed material.

8. The method of claim 7, further comprising:

(e) comminuting the oxidized material to remove, at least partially, an oxidative film on at least some particles of the oxidized material, wherein the comminuted and oxidized material is subjected to flotation in step (c).

9. The method of claim 8, further comprising:

(f) conditioning the comminuted and oxidized material by contacting the comminuted and oxidized material with a collector that renders the carbonaceous material more hydrophobic, wherein the conditioned comminuted and oxidized material is subjected to flotation in step (c).

10. The method of claim 9, wherein at least one of a sulfide depressant and carbonaceous material activator is contacted with the comminuted and oxidized material during conditioning.

11. The method of claim 9, further comprising:

(g) comminuting the rougher concentrate to provide a comminuted rougher concentrate;

(h) conditioning the comminuted rougher concentrate by contacting the comminuted rougher concentrate with the collector; and

(i) floating the comminuted rougher concentrate to form cleaner tails comprising most of the gold and/or silver in the rougher concentrate and a cleaner concentrate comprising most of the carbonaceous material in the rougher concentrate.

12. The method of claim 11, further comprising:

recovering gold and/or silver from the rougher and cleaner tails.

13. A method, comprising:

(a) providing a feed material comprising a precious metal, at least about 0.1 wt. % sulfide sulfur, and 0.3 to about 10 wt. % carbonaceous materials;

(b) pressure oxidizing at least a portion of the sulfide sulfur in the feed material to provide an oxidized material, wherein at least most of the gold and/or silver and carbonaceous materials remain in the oxidized feed material; and

(c) thereafter floating the oxidized feed material to separate the material into a rougher concentrate comprising at least most of the gold and/or silver and rougher tails comprising at least about 25% of the carbonaceous materials in the feed material.

14. The method of claim 13, further comprising:

(e) comminuting the oxidized material to remove, at least partially, an oxidative film on at least some particles of the oxidized material, wherein the comminuted and oxidized material is subjected to flotation in step (c).

15. The method of claim 14, further comprising:

(f) conditioning the comminuted and oxidized material by contacting the comminuted and oxidized material with a collector that renders the carbonaceous material more hydrophobic, wherein the conditioned comminuted and oxidized material is subjected to flotation in step (c).

16. The method of claim 15, wherein at least one of a carbon depressant and sulfide activator is contacted with the comminuted and oxidized material during conditioning.

17. The method of claim 15, further comprising:

(g) comminuting the rougher tails to provide a comminuted rougher tails;

(h) conditioning the comminuted rougher tails by contacting the comminuted rougher tails with the collector; and

(i) floating the comminuted rougher tails to form a cleaner concentrate comprising most of the gold and/or silver in the rougher tails and cleaner tails comprising most of the carbonaceous material in the rougher tails.

18. The method of claim 17, further comprising:

recovering gold and/or silver from the rougher and cleaner concentrates.