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US 4,552,589 AGranted
Process for the recovery of gold from refractory ores by pressure oxidation
AssigneeGetty Oil Company
InventorsPeter G. Mason, Frank D. Wicks, John C. Gathje
Life of this patent
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Abstract
A process for recovering precious metals from a refractory ore by forming a slurry which is heated to a temperature in excess of about 150.degree. C. at an oxygen partial pressure in excess of about 10 psia for an effective amount of time to form a partially oxidized slurry which is then subjected to carbon-in-leach treatment to separate the precious metals.
Claims27
A process for recovering gold from a refractory ore slurry, said process comprising the steps of:
- introducing the slurry to at least one agitated autoclave maintained at an autoclave temperature in excess of about 150.degree. C. and an autoclave oxygen partial pressure in excess of about 10 psia;
- agitating the slurry to allow oxygen to oxidize at least part of the substances which cause the ore to be refractory to form an oxidized slurry;
- passing the oxidized slurry to a plurality of stages in which the oxidized slurry is contacted with a cyanide and activated charcoal, the charcoal flowing in countercurrent fashion with said oxidized slurry whereby precious metals are transferred to the activated charcoal;
- and
- separating the activated charcoal from the oxidized slurry.
2 more elements
A process for recovering gold, said process comprising the steps of:
- forming an ore slurry from a refractory gold bearing ore;
- introducing the slurry to to at least one autoclave which is maintained at an autoclave temperature in excess of about 150.degree. C. and an autoclave oxygen partial pressure maintained in excess of about 10 psia;
- agitating the slurry sufficiently to oxidize at least part of the substances which cause the ore to be refractory to form an oxidized slurry;
- passing the oxidized slurry to a plurality of stages in which the oxidized slurry is contacted with a cyanide and activated charcoal at a cyanidation temperature less than about 50.degree. C., said charcoal flowing in countercurrent fashion with said oxidized slurry whereby gold is transferred to the activated charcoal;
- and
- separating the activated charcoal from the oxidized slurry.
3 more elements
A process for recovering gold, said process comprising the steps of:
- forming an ore slurry by grinding a refractory gold bearing ore to form a slurry which is mixed with a diluent stream;
- introducing the slurry to at least one autoclave which is maintained at an autoclave temperature in excess of about 150.degree. C. and an autoclave oxygen partial pressure maintained in excess of about 10 psia;
- agitating the slurry to oxidize substances which cause the ore to be refractory to form an oxidized slurry;
- cooling the oxidized slurry to a temperature less than about 150.degree. C.;
- passing the oxidized slurry to a plurality of stages in which the oxidized slurry is contacted with a cyanide and activated charcoal, the activated charcoal flowing in countercurrent fashion with the oxidized slurry whereby gold is transferred to the activated charcoal;
- separating the activated charcoal from the oxidized slurry;
- collecting a tailings stream from the oxidized slurry;
- treating a water portion of the tailings stream to destroy any free cyanide and form a treated reclaimed water stream;
- and
- recycling the treated reclaimed water stream to a step of the process upstream from the step of passing the oxidized slurry to a plurality of stages.
7 more elements
Dependencies are inferred from the claim text.