Barrick Gold Corporation

Noelene Ahern

Yeonuk Choi

Daniel Hillier

Ahmad Ghahremaninezhad Gharelar

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

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

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.

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Burnaby, Canada

Noelene Ahern