International Journal of Minerals, Metallurgy and Materials
Volume 17, Number 1, February 2010, Page 1
DOI: 10.1007/s12613-010-0101-6
Corresponding author: Hai-peng Wang E-mail: haipeng_wang@yahoo.com
© University of Science and Technology Beijing and Springer-Verlag Berlin Heidelberg 2010
Processing technologies for gold-telluride ores
Jian Zhang
1)
, Yao Zhang
1)
, William Richmond
2)
, and Hai-peng Wang
1)
1) Department of Metallurgical Engineering and Extractive Metallurgy, Curtin University of Technology, WASM, Kalgoorlie, WA 6430, Australia
2) Department of Applied Chemistry, Curtin University of Technology, Bentley, WA 6102, Australia
(Received: 28 November 2008; revised: 6 January 2009; accepted: 1 March 2009)
Abstract: Gold telluride ores are important gold refractory ores due to the presence of sulfides and other gangue materials. The classification
and main physical properties of gold telluride ores were described, and possible treatment methods including flotation, leaching, and oxida-
tion were reviewed. The results show that flotation procedures are much easier for gold tellurides compared to other refractory gold-bearing
ores. For the conventional cyanide leaching process, pretreatment such as oxidation is required to achieve high gold recovery. Roasting is a
relatively simple but not environment-friendly method; bio-oxidation technology seems to be more suitable for the oxidation of flotation
concentrate. Other treatment methods involve cyanide leaching, thiourea leaching, ammoniacal thiosulfate leaching, carbon-in-pulp, and
resin-in-pulp, all of which are less commonly utilized.
Keywords: gold-tellurides; flotation; leaching; oxidation
1. Introduction
Gold occurs primarily in its native form and secondarily
as gold solid-solution of which tellurides are an example [1].
Gold extraction from tellurides has attracted increasing at-
tention over the past decades. Gold tellurides have been
commercially treated in Kalgoorlie (Western Australia),
Vatukoula (Fiji), Cripple Creek (Colorado), and Kirkland
Lake (Ontario). The first modern treatment of gold-telluride
ores was performed in 1891 in the Cripple Creek goldfield
near the Rocky Mountains in Colorado. Kalgoorlie, in
Western Australia, had the honor of being the second major
goldfield, and tellurides were successfully processed to ex-
tract gold. In a modern gold processing plant, the recovery
can be up to 98% with the aid of the latest concentration and
smelting techniques. A successful gold recovery strategy re-
lies on a fundamental understanding of the ore mineralogy
and its chemical/physical behaviors under various leach,
flotation, and oxidation conditions. An overview of the
processing techniques/options for gold telluride ores was
given and their advantages and limitations were discussed in
this paper.
2. Classification of gold-telluride ores
It was well known that gold was commonly associated
with tellurium minerals. The cooccurrence of tellurium with
noble metals such as gold and silver was attributed to the
semi-metallic nature of tellurium. The composition varied
significantly from different tellurium minerals. For instance,
gold-telluride ores could be classified into six mineral
groups: calaverite (AuTe
2
), sylvanite [(Ag,Au)
2
Te
4
], mont-
brayite [(AuSb)
2
Te
3
], krennerite [(Au
1x
,Ag
x
)Te
2
], petzite
(Ag
3
AuTe
2
), and muthmannite [(Ag,Au)Te
2
].
The physical properties and deposit location of these six
minerals are tabulated in Table 1. Among them, Calaverite
was the simplest and most common association of tellurium
with gold. It was also the most common gold bearing min-
eral apart from native gold.
3. Processing options
Unlike free gold, gold tellurides do not undergo rapid
dissolution in the conventional alkaline cyanide leach solu-
tion. Therefore, alternative treatments must be applied to