Gold recovery from thiosulfate leaching
AssigneeThe University of British Columbia
InventorsHongguang Zhang, David Dreisinger
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Abstract
Processes for recovering gold from copper-gold ores thiosulfate leaching or gold ores copper catalyzed thiosulfate leaching using ion exchange technology are disclosed. The processes include subjecting the gold-bearing and copper-bearing thiosulfate solution to a pH and/or temperature adjustment to reduce tetrathionate concentration in the thiosulfate solution prior to contacting with an ion exchange resin. The ion exchange resin once loaded with gold and optionally copper is eluted with a mixture of sodium tetrathionate, ammonium thiosulfate and sodium sulfite. Gold and optionally copper are recovered from the eluate by electrowinning or precipitation.
Claims34
A process for loading gold onto an ion exchange resin from a gold-bearing thiosulfate solution having an initial tetrathionate concentration, the process comprising:
- (a) adjusting the pH of the gold-bearing thiosulfate solution for a sufficient period of time to produce a gold-bearing loading solution having a tetrathionate concentration reduced relative to the initial tetrathionate concentration;
- and
- (b) contacting the gold-bearing loading solution with an ion exchange resin to load gold onto the resin to produce a loaded resin.
A process for loading gold onto an ion exchange resin from a gold-bearing thiosulfate solution having an initial tetrathionate concentration, the process comprising:
- (a) adjusting the temperature of the gold-bearing thiosulfate solution for a sufficient period of time to produce a gold-bearing loading solution having a tetrathionate concentration reduced relative to the initial tetrathionate concentration;
- and
- (b) contacting the gold-bearing loading solution with an ion exchange resin to load gold onto the resin to produce a loaded resin.
A process for eluting gold or copper loaded on an ion-exchange resin comprising passing an eluant containing a sulfite through the resin, wherein the eluant further comprises a thiosulfate, the concentration of said thiosulfate being selected to stabilize eluted gold and copper.
A process for recovering gold from a slurry, wherein the slurry comprises a solid ore residue and a gold-bearing thiosulfate leach solution having an initial tetrathionate concentration, the process comprising:
- (a) adjusting the pH of the slurry for a sufficient period of time to produce a loading slurry, wherein the loading slurry has a tetrathionate concentration reduced relative to the initial tetrathionate concentration;
- (b) contacting the loading slurry with an ion-exchange resin to adsorb gold onto the resin to produce a loaded resin;
- (c) separating the loaded resin from the loading slurry;
- (d) eluting gold from loaded resin to produce a gold-bearing eluate;
- and
- (e) recovering gold from the gold-bearing eluate.
A process for recovering gold from a slurry, wherein the slurry comprises a solid ore residue and a gold-bearing and copper-bearing thiosulfate leach solution having an initial tetrathionate concentration, the process comprising;
- (a) adjusting the pH of the slurry for a sufficient period of time to produce a loading slurry having a tetrathionate concentration reduced relative to the initial tetrathionate concentration;
- (b) contacting the loading slurry with an ion-exchange resin to adsorb gold and copper from the loading slurry onto the resin to produce a loaded resin,
- (c) separating the loaded resin from the slurry;
- (d) eluting copper from the loaded resin to produce a copper-bearing eluate;
- (e) eluting gold from the loaded resin to produce a gold-bearing eluate;
- and
- (f) recovering gold from the gold-bearing eluate.
A process for recovery gold from a slurry, wherein the slurry comprises a solid ore residue and a gold-bearing and copper-bearing thiosulfate leach solution having an initial tetrathionate concentration, the process comprising:
- (a) adjusting the pH and temperature of the slurry for a sufficient period of time to produce a loading slurry having a tetrathionate concentration reduced relative to the initial concentration;
- (b) contacting the loading slurry with an ion-exchange resin to adsorb gold and copper onto the resin to produce a loaded resin,
- (c) separating the loaded resin from the slurry;
- (d) eluting copper from the loaded resin to produce a copper-bearing eluate;
- eluting gold from the loaded resin to produce a gold-bearing eluate;
- and
- (e) recovering gold from the gold-bearing eluate.
A process for recovery gold from a slurry, wherein the slurry comprises a solid ore residue and a gold-bearing and copper-bearing thiosulfate leach solution having an initial tetrathionate concentration, the process comprising;
- (a) adjusting the pH of the slurry for a sufficient period of time to produce a loading slurry having a tetrathionate concentration reduced relative to the initial concentration;
- (b) separating the solid ore residue from the slurry to produce a gold-bearing and copper-bearing loading solution;
- (c) contacting the gold-bearing and copper-bearing loading solution with an ion-exchange resin to adsorb gold and copper from the gold-bearing and copper-bearing loading solution onto the resin to produce a loaded resin;
- (d) eluting copper from the loaded resin to produce a copper-bearing eluate;
- (e) eluting gold from the loaded resin to produce a gold-bearing eluate;
- and
- (f) recovering gold from the gold-bearing eluate.
Dependencies are inferred from the claim text.