Barrick Gold Corporation

Akzo Nobel Chemicals International B.v.

Yeonuk Choi

Ahmad Ghahremaninezhad Gharelar

Samir Chefal

Jacques McMullen

Peter Kondos

Samir Chefai

Noelene Ahern

Peter D Kondos

Daniel Hillier

John William Langhans, Jr

Qiong Zhou

Qiankun Wang

Junhua Jiang

Mark Graham Aylmore

Gus Van Weert

John William Langhans

Mark Aylmore

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.

Method for pre-treatment of gold-bearing oxide ores

A method and system are provided in which a gold and/or silver-collecting resin-in-leach circuit comprises both co-current and counter-current sections.

Co-current and counter current resin-in-leach in gold leaching processes

The disclosure relates to the oxidation and immobilization of trivalent arsenic from arsenic-containing solutions. The process includes oxidation of trivalent arsenic (As) species to the pentavalent state (As). 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.

Method for arsenic oxidation and removal from process and waste solutions

A process for recovery of precious metals from ores or concentrates containing refractory carbonaceous material by cyanidation leaching. The process involves addition to the ores or concentrates at least one cationic surfactant before or during the addition of cyanide-containing solution. The agent enables the recovery of precious metals by cyanidation from high preg-robbing carbonaceous ores and improves the recovery of precious metals by cyanidation from medium to low preg-robbing carbonaceous ores. The agent also prevents froth and foaming formation during the cyanidation process.

Use of cationic surfactants in the cyanidation of refractory carbonaceous ores for recovery of metals

The present disclosure is directed to 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 sorbed trithionate to thiosulfate. The desorbed thiosulfate is contacted with an oxidant and converted to trithionate for eluant recycle.

Method for recovering precious metals and copper from leach solutions

In an embodiment, the present invention relates to an apparatus and a process for producing a concentrated form of basic zinc sulphate from a, typically dilute, acidic zinc sulphate-bearing solution. The process embodiment comprises the steps of precipitating the zinc, preferably primarily as basic zinc sulphate, from the acidic zinc sulphate solution, preferably using calcium oxide, in such a way as to promote the formation of separate gypsum crystals and basic zinc sulphate particles, and upgrading the zinc content in the precipitates by separating the basic zinc sulphate from the gypsum using size separation techniques.

Production of zinc sulphate concentrates from a dilute zinc sulphate solution

The present invention is directed to flotation of refractory gold sulfide ores and to pressure oxidized residue neutralization using flotation tailings that have been contacted with an off gas of pressure oxidation.

Process for controlling acid in sulfide pressure oxidation processes

The present invention is directed to a precious metal recovery process in which basic ferric sulphates and/or jarosites are controlled by hot curing of the autoclave discharge slurry followed by decomposition of argentojarosite using strong acid consumers.

Process for reduced alkali consumption in the recovery of silver

A method for suppressing mercury dissolution during pressure oxidation of precious metal-containing materials in the presence of halogens and halides is provided. Pressure oxidation is performed under controlled oxidative conditions to maintain the mercury predominantly in the solid residue.

Process for mercury control during pressure oxidation

A method for recovering zinc ions by selective zinc sulfide precipitation from an aqueous solution comprising zinc ions and metal ions of a metal that precipitates as a metal sulfide at a pH lower than a pH at which zinc ions precipitate as a zinc sulfide.

Selective precipitation of metal sulfides

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.

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Oakville, Canada

Yeonuk Choi