A Study of the Modes of Gold Loss in the Calcium Thiosulfate Leaching of Preg-robbing Ores

The evermore increasing complexity of gold ores is forcing operations to seek alternative gold leaching reagents to the traditional use of cyanidation. At the Barrick Goldstrike mine, the implementation of a non-toxic thiosulfate leaching process is about to become an industrial reality. With modification to the existing infrastructure and leaching circuit, this new process allows for the continued use of autoclaves that were otherwise rendered obsolete. Alkaline pressure oxidation followed by calcium thiosulfate leaching and gold recovery by resin adsorption is used to treat refractory ores not amendable by conventional cyanidation. Nonetheless, this alternative and complex leaching process is found to yield variable gold recoveries in the absence of an anion exchange resin in the leaching step. The mechanisms by which this loss in gold occurs is still unknown. The objective of this work is thus to investigate the modes of gold loss during CaTS leaching.

Faculty Supervisor:

Dr. David Dreisinger

Student:

Renaud Daenzer

Partner:

Barrick Gold Corporation

Discipline:

Engineering - other

Sector:

Mining and quarrying

University:

University of British Columbia