1755
Establishment of a Sustainable and Eco-Friendly Scheme for
Recovery of Gold from Double Refractory Ores
Azizbek Buronov, Sanghee Jeon, Labone Godirilwe,
Kazutoshi Haga, Atsushi Shibayama
Department of Geosciences, Geotechnology, and Materials Engineering for Resources,
Graduate School of International Resource Sciences, Akita University, Akita, Japan
ABSTRACT: A novel green-hydrometallurgy scheme was established for sustainable Au extraction from low-
grade refractory ores. Pyrite oxidation with a ferric solution obtained from a bio-oxidation plant with sustainable
catalysts gained from natural ores was executed, and Au was extracted in an eco-friendly thiosulfate solvent. The
results showed that Au extraction was enhanced three-fold compared with direct leaching. Subsequently, the
recovery/upgrading of Au was carried out by utilizing tailings (e.g., pyrite) with a thiosulfate decomposition
reaction. The results showed that Au was recovered and upgraded by 500–700 folds. Therefore, the results
indicate that this sustainable green-mining scheme is effective in improving Au extraction from low-grade
refractory ores to achieve a carbon-neutral society.
Keywords: Green mining, Refractory ores, Gold, Pyrite oxidation, Thiosulfate, Flotation
INTRODUCTION
One important concern is the increasing level of green-
house gases resulting from industrial activities (Hegerl et
al., 2019), which leads to climate change. This situation
initiated global efforts to achieve a carbon-neutral soci-
ety, where the mitigation of climate change is maintained
(Chen et al., 2022).
Renewable energy technologies are increasingly impor-
tant for reducing fossil fuels and minimizing greenhouse
gas emissions. Key to this sustainable transition are tech-
nologies such as solar panels, wind turbines, and fuel cells.
However, these technologies require a significant amount
of critical metals, highlighting the necessity for sustainable
extraction and processing methods.
Gold (Au), known for its outstanding conductivity
and resistance to corrosion, is integral in various electronic
devices, particularly in renewable energy applications.
In solar energy, gold is utilized in thin-film photovolta-
ics, enhancing the efficiency of organic photovoltaic cells
(Wadams et al., 2014), which is crucial for next-generation
solar technology. This is due to gold’s ability to facilitate
efficient energy conduction and electron transfer. Similarly,
in wind energy systems, the conductive properties of gold
are essential for the electrical interfaces and components in
wind turbines (Dudem et al., 2018).
In gold-hydrometallurgy, the first stage is to dissolve
gold using suitable lixiviants, followed by the recovery of
extracted gold ions from pregnant leach solutions (Jeon et
al., 2019, 2020). Historically, in the leaching stage, cya-
nide is the most commonly used lixiviants to extract gold.
Over time, there has been an increasing development of
double refractory gold ores (DRGO), and when those con-
ventional methods are employed for the DRGO, unfortu-
nately, these are resistant to conventional processing due to
Establishment of a Sustainable and Eco-Friendly Scheme for
Recovery of Gold from Double Refractory Ores
Azizbek Buronov, Sanghee Jeon, Labone Godirilwe,
Kazutoshi Haga, Atsushi Shibayama
Department of Geosciences, Geotechnology, and Materials Engineering for Resources,
Graduate School of International Resource Sciences, Akita University, Akita, Japan
ABSTRACT: A novel green-hydrometallurgy scheme was established for sustainable Au extraction from low-
grade refractory ores. Pyrite oxidation with a ferric solution obtained from a bio-oxidation plant with sustainable
catalysts gained from natural ores was executed, and Au was extracted in an eco-friendly thiosulfate solvent. The
results showed that Au extraction was enhanced three-fold compared with direct leaching. Subsequently, the
recovery/upgrading of Au was carried out by utilizing tailings (e.g., pyrite) with a thiosulfate decomposition
reaction. The results showed that Au was recovered and upgraded by 500–700 folds. Therefore, the results
indicate that this sustainable green-mining scheme is effective in improving Au extraction from low-grade
refractory ores to achieve a carbon-neutral society.
Keywords: Green mining, Refractory ores, Gold, Pyrite oxidation, Thiosulfate, Flotation
INTRODUCTION
One important concern is the increasing level of green-
house gases resulting from industrial activities (Hegerl et
al., 2019), which leads to climate change. This situation
initiated global efforts to achieve a carbon-neutral soci-
ety, where the mitigation of climate change is maintained
(Chen et al., 2022).
Renewable energy technologies are increasingly impor-
tant for reducing fossil fuels and minimizing greenhouse
gas emissions. Key to this sustainable transition are tech-
nologies such as solar panels, wind turbines, and fuel cells.
However, these technologies require a significant amount
of critical metals, highlighting the necessity for sustainable
extraction and processing methods.
Gold (Au), known for its outstanding conductivity
and resistance to corrosion, is integral in various electronic
devices, particularly in renewable energy applications.
In solar energy, gold is utilized in thin-film photovolta-
ics, enhancing the efficiency of organic photovoltaic cells
(Wadams et al., 2014), which is crucial for next-generation
solar technology. This is due to gold’s ability to facilitate
efficient energy conduction and electron transfer. Similarly,
in wind energy systems, the conductive properties of gold
are essential for the electrical interfaces and components in
wind turbines (Dudem et al., 2018).
In gold-hydrometallurgy, the first stage is to dissolve
gold using suitable lixiviants, followed by the recovery of
extracted gold ions from pregnant leach solutions (Jeon et
al., 2019, 2020). Historically, in the leaching stage, cya-
nide is the most commonly used lixiviants to extract gold.
Over time, there has been an increasing development of
double refractory gold ores (DRGO), and when those con-
ventional methods are employed for the DRGO, unfortu-
nately, these are resistant to conventional processing due to