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Towards Net Zero: Opportunities for CO
2 Utilization in
Nickel Processing
Shaihroz Khan
Decarbonization and Operations Optimisation, Ausenco
Landon Jackson, Usman Siddiqui and Rajiv Chandramohan
Operations Optimisation, Ausenco
ABSTRACT: The mining industry, driven by a collective desire to minimize its carbon footprint, is actively
exploring ways to reduce Green House Gas Emissions (GHGe). Among the methods being considered are
optimizing existing assets, adopting more efficient processing methods, and offsetting emissions in the value
chain through sequestration. This paper delves into the cost range for CO2 capture and CO2 sequestration
technologies, focusing on the latter. It also presents innovative approaches to reduce CO2 emissions and enhance
the extraction of nickel from low-grade ores through CO2 sequestration. The potential for CO2 sequestration
by carbonating available Mg2+ ions in the process streams of ultramafic nickel sulfide and nickel laterite ores is a
beacon of hope, with a high-level technical comparison between the various routes revealing CO2 sequestration
in nickel laterite as a particularly promising avenue.
NICKEL PROCESSING AS A POTENTIAL
CO2 CAPTURE, STORAGE, AND
UTILIZATION (CCUS) SECTOR:
With increasing metal demand, CO2 emissions are rising
due to the processing of low-grade ores. Mining contrib-
utes around 4–7% of global carbon emissions (Henderson
and Maksimainen, 2020). For perspective, a nickel plant
with 50,000 t/d would produce roughly 550 t CO2/d
emissions considering a diesel power generator with 40%
efficiency based on 31 GJ/t Ni production and 38 MJ/
liter of the energy content of diesel (Allen, 2021 US EPA,
2015). Considering the potential financial implications, as
per Canada’s OBPS carbon pricing rate by 2030, the car-
bon tax associated with such emissions would amount to
around CA$30 M annually (assuming 340 days of plant
operation). This is a significant cost that could be avoided
with the proper measures.
An increasing number of countries are establishing
legislation to achieve net zero emission (NZE) targets to
meet climate change objectives. Due to the rising demand
for critical metals such as nickel, increased production is
required to establish a clean energy infrastructure and
achieve NZEs. Thus, processing techniques and technolo-
gies to reduce the carbon footprint of processing low-grade
nickel ores are attracting global attention.
Greenhouse Gas emissions (GHGe) for low-grade
nickel ore processing can be reduced through:
1. Energy efficiency improvements in comminution
and other unit operations
2. Utilizing greener energy sources for power genera-
tion replacing fossil-based power generation
3. Developing a technology to sequester the carbon
emissions
Towards Net Zero: Opportunities for CO
2 Utilization in
Nickel Processing
Shaihroz Khan
Decarbonization and Operations Optimisation, Ausenco
Landon Jackson, Usman Siddiqui and Rajiv Chandramohan
Operations Optimisation, Ausenco
ABSTRACT: The mining industry, driven by a collective desire to minimize its carbon footprint, is actively
exploring ways to reduce Green House Gas Emissions (GHGe). Among the methods being considered are
optimizing existing assets, adopting more efficient processing methods, and offsetting emissions in the value
chain through sequestration. This paper delves into the cost range for CO2 capture and CO2 sequestration
technologies, focusing on the latter. It also presents innovative approaches to reduce CO2 emissions and enhance
the extraction of nickel from low-grade ores through CO2 sequestration. The potential for CO2 sequestration
by carbonating available Mg2+ ions in the process streams of ultramafic nickel sulfide and nickel laterite ores is a
beacon of hope, with a high-level technical comparison between the various routes revealing CO2 sequestration
in nickel laterite as a particularly promising avenue.
NICKEL PROCESSING AS A POTENTIAL
CO2 CAPTURE, STORAGE, AND
UTILIZATION (CCUS) SECTOR:
With increasing metal demand, CO2 emissions are rising
due to the processing of low-grade ores. Mining contrib-
utes around 4–7% of global carbon emissions (Henderson
and Maksimainen, 2020). For perspective, a nickel plant
with 50,000 t/d would produce roughly 550 t CO2/d
emissions considering a diesel power generator with 40%
efficiency based on 31 GJ/t Ni production and 38 MJ/
liter of the energy content of diesel (Allen, 2021 US EPA,
2015). Considering the potential financial implications, as
per Canada’s OBPS carbon pricing rate by 2030, the car-
bon tax associated with such emissions would amount to
around CA$30 M annually (assuming 340 days of plant
operation). This is a significant cost that could be avoided
with the proper measures.
An increasing number of countries are establishing
legislation to achieve net zero emission (NZE) targets to
meet climate change objectives. Due to the rising demand
for critical metals such as nickel, increased production is
required to establish a clean energy infrastructure and
achieve NZEs. Thus, processing techniques and technolo-
gies to reduce the carbon footprint of processing low-grade
nickel ores are attracting global attention.
Greenhouse Gas emissions (GHGe) for low-grade
nickel ore processing can be reduced through:
1. Energy efficiency improvements in comminution
and other unit operations
2. Utilizing greener energy sources for power genera-
tion replacing fossil-based power generation
3. Developing a technology to sequester the carbon
emissions