The present disclosure is directed to a thiosulfate leaching process for precious metal recovery. In the process, a precious metal is leached from a precious metal-bearing material by contacting the precious metal-bearing material with a particulate carbon-based material, a thiosulfate, an anion exchange resin and an oxidant to form a slurry comprising the leached precious metal. The particulate carbon-based materials serves as a catalyst for dissolution rates and precious metal recoveries during the leaching.
C22B 3/12 - Extraction de composés métalliques par voie humide à partir de minerais ou de concentrés par lixiviation dans des solutions inorganiques alcalines
The present disclosure is directed to a process for thiosulfate leaching of a precious metal-containing material and recovering a precious metal from a pregnant leach solution using a resin extractant. The precious metal is eluted from the loaded resin optionally using an eluant comprising trithionate. Various process improvements include maintaining the thiosulfate-containing leach solution substantially free of thiols and amines, maintaining a concentration of a sulfide in the thiosulfate leach solution of no more than about 100 ppm, recycling the barren resin free of contact with a sulfide, bisulfide, and polysulfide, and/or maintaining a concentration of tetrathionates, trithionate s, sulfur-oxygen anions, and/or combinations thereof within about 50% of a concentration level of the one or more of tetrathionates, trithionates, sulfur-oxygen anions, the combinations thereof in the precious metal-containing solution before contact with the recycled barren resin.
C22B 3/12 - Extraction de composés métalliques par voie humide à partir de minerais ou de concentrés par lixiviation dans des solutions inorganiques alcalines
The disclosure relates to pre-treatment of precious metal-bearing oxide ores, prior to precious metal leaching by thiosulfate. The process comprises mixing oxide ore in oxygenated water in the presence of a carbon-based material (e.g., activated carbon or other type of carbon). The carbon-based material can be separated from the ore slurry, and, the gold is thereafter leached by a thiosulfate lixiviant.
The disclosure relates to the oxidation and immobilization of trivalent arsenic from arsenic-containing solutions. The process includes oxidation of trivalent arsenic (As3+) species to the pentavalent state (As5+). A carbon additive (e.g., activated carbon) and oxygen are used to promote the arsenic oxidation processes. After oxidation of arsenic to the pentavalent state, the arsenic can be removed by precipitation to ferric arsenate or calcium arsenate or other arsenic containing compounds known in the art. The oxidation of arsenic can also occur simultaneously with the production and precipitation of ferric arsenate (e.g., scorodite). Ferrous iron can be oxidized to ferric iron in the presence of activated carbon and oxygen.
A method to recover gold lost in roaster calcine-leach tailings, due to the formation of cyanide refractory compounds or morphologies during the roasting process. The process can include acid leaching of magnetic concentrate from roaster leach tailings, combining the acid leach slurry to the pre-acidulation tank for pressure oxidation feed, acid pressure oxidation of the pressure oxidation feed, and recovery of gold. In an embodiment, the acid leaching forms a dissolved iron-containing leach slurry and the iron-containing leach slurry is contacted with a precious metal- and carbonate-containing material and thereafter precious metal is recovered from the precious metal- and carbonate-containing material.
C22B 3/22 - Traitement ou purification de solutions, p.ex. de solutions obtenues par lixiviation par des procédés physiques, p.ex. par filtration, par des moyens magnétiques
C22B 3/06 - Extraction de composés métalliques par voie humide à partir de minerais ou de concentrés par lixiviation dans des solutions inorganiques acides
C22B 3/44 - Traitement ou purification de solutions, p.ex. de solutions obtenues par lixiviation par des procédés chimiques
A process for recovering a precious metal from a pregnant leach solution using a resin extractant. The precious metal is eluted from the loaded resin using an eluant comprising trithionate. The barren resin is contacted with a sulfide, bisulfide, and/or polysulfide to convert sorted trithionate to thiosulfate. The desorbed thiosulfate is contacted with an oxidant and converted to trithionate for eluant recycle.
C22B 3/24 - Traitement ou purification de solutions, p.ex. de solutions obtenues par lixiviation par des procédés physiques, p.ex. par filtration, par des moyens magnétiques par adsorption sur des substances solides, p.ex. par extraction avec des résines solides
7.
CO-CURRENT AND COUNTER CURRENT RESIN-IN-LEACH IN GOLD LEACHING PROCESSES
A method and system are provided in which a gold and/or silver-collecting resin-in-leach or resin-in-pulp circuit comprises both co-current and counter-current sections, specifically in thiosulfate leach systems.
C22B 3/12 - Extraction de composés métalliques par voie humide à partir de minerais ou de concentrés par lixiviation dans des solutions inorganiques alcalines
C22B 3/22 - Traitement ou purification de solutions, p.ex. de solutions obtenues par lixiviation par des procédés physiques, p.ex. par filtration, par des moyens magnétiques
C22B 3/24 - Traitement ou purification de solutions, p.ex. de solutions obtenues par lixiviation par des procédés physiques, p.ex. par filtration, par des moyens magnétiques par adsorption sur des substances solides, p.ex. par extraction avec des résines solides
C22B 3/42 - Traitement ou purification de solutions, p.ex. de solutions obtenues par lixiviation par extraction utilisant l'échange d'ions
8.
ALKALINE AND ACID PRESSURE OXIDATION OF PRECIOUS METAL-CONTAINING MATERIALS
The present invention is directed to a precious metal recovery process in which an acid sulfidic feed material is subjected to acid pressure oxidation and an alkaline sulfidic feed material is subjected to alkaline pressure oxidation, with the discharge slurries from the pressure oxidation processes being combined to reduce neutralization requirements prior to precious metal recovery.
Embodiments of the present invention are directed to flotation of sulfidic materials following aerating by an oxidizing gas and contacting by a sulfoxy reagent.
A method for recovering zinc ions by selective sulfide precipitation from an aqueous solution comprising zinc ions and metal ions of a metal that precipitates as metal sulfide at a pH lower than a pH at which zinc ions precipitate as zinc sulfide, the method comprising contacting the aqueous solution with a source of sulfide to precipitate the metal ions as the metal sulfide while avoiding the precipitation of the zinc sulfide thereby yielding the metal sulfide precipitate and a solution comprising zinc ions, and contacting the solution comprising zinc ions with a source of sulfide ion in a concentration sufficient to precipitate the zinc ions as the zinc sulfide.
Precious metal recovery by thiosulfate leaching where thiosulfate lixiviant is generated in situ employing elemental sulfur generated from partial oxidation of sulfidic precious metal-bearing feed and/or employing reactants from processing effluent.
C22B 3/06 - Extraction de composés métalliques par voie humide à partir de minerais ou de concentrés par lixiviation dans des solutions inorganiques acides
C22B 3/12 - Extraction de composés métalliques par voie humide à partir de minerais ou de concentrés par lixiviation dans des solutions inorganiques alcalines
C22B 3/14 - Extraction de composés métalliques par voie humide à partir de minerais ou de concentrés par lixiviation dans des solutions inorganiques alcalines contenant de l'ammoniaque ou des sels d'ammonium
C22B 3/44 - Traitement ou purification de solutions, p.ex. de solutions obtenues par lixiviation par des procédés chimiques
12.
TREATMENT OF RECLAIM WATER FOR USE IN METALS RECOVERY
A process for improving the recovery of gold from gold-bearing solutions formed from carbonaceous ore using a cyanide lixiviant, the process comprising treatment of tailings pond water with H2SO5 before introduction into a gold-recovery system such that the water has a total concentration of CN- and SCN- reduced by at least 30%.
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