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US 8,262,768 B2Granted
Method to improve recovery of gold from double refractory gold ores
AssigneeBarrick Gold Corporation
InventorsBarun Gorain, Peter Kondos
Life of this patent
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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.
Claims17
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) comminuting the oxidized material to remove, at least partially, an oxidative film on at least some particles of the oxidized feed material;
- (d) after step (b), floating the comminuted and 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 wt. % of the carbonaceous materials in the feed material, wherein the comminuted and oxidized feed material is free of precious metal leaching prior to the floating step;
- (e) comminuting the second fraction to provide a comminuted second fraction;
- (f) floating the comminuted second fraction to form cleaner tails comprising most of the gold and/or silver in the comminuted second fraction and a cleaner concentrate comprising most of the carbonaceous material in the comminuted second fraction;
- and
- (g) after floating is completed, thereafter recovering the gold and/or silver from the first fraction and the cleaner tails, wherein the first fraction and the cleaner tails comprise at least about 90% of the gold and/or silver in the oxidized material.
5 more elements
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) after step (b) floating the oxidized feed material to separate the material into a first fraction comprising at least about 70 wt. % of the gold and/or silver in the oxidized feed material and a second fraction comprising no less than about 40 wt. % of the carbonaceous materials in the feed material;
- (d) comminuting the second fraction to provide a comminuted second fraction;
- and
- (e) floating the comminuted second fraction to form cleaner tails comprising most of the gold and/or silver in the comminuted second fraction and a cleaner concentrate comprising most of the carbonaceous material in the comminuted second fraction, wherein the first fraction and the cleaner tails comprise at least about 90% of the gold and/or silver in the oxidized material.
4 more elements
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 first fraction comprising at least most of the gold and/or silver and a second fraction comprising at least about 25 wt. % of the carbonaceous materials in the feed material;
- (d) comminuting the second fraction to provide a comminuted second fraction;
- and
- (e) floating the comminuted second fraction to form cleaner concentrate comprising most of the gold and/or silver in the comminuted second fraction and a cleaner tails comprising most of the carbonaceous material in the comminuted second fraction, wherein the first fraction and the cleaner concentrate comprise at least about 90% of the gold and/or silver in the oxidized material.
4 more elements
Dependencies are inferred from the claim text.