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Optimising Tribocharger Designs for Separating Granular
Material Using the Discrete Element Method
Joshua N. Rasera, Jan J. Cilliers
Imperial College London
Kathryn Hadler
European Space Resources Innovation Centre
ABSTRACT: The optimisation of tribochargers using the discrete element method for the separating granular
materials, essential for dry mineral beneficiation, is studied. Various tribocharger designs are compared an
optimum is identified. The suitability of the design for charging other materials is considered. We extend our
analysis to simulate the conditions on the Moon, adapting the tribocharger design its unique environment.
We highlight the versatility of our modelling approach and its potential for mineral processing on Earth and
in space, particularly in the context of space resource utilisation. We provide insights into the adaptability and
effectiveness of tribocharging technologies under diverse conditions.
INTRODUCTION
Space Resource Utilisation (SRU) is integral to human
exploration and habitation of space. A critical first step for
SRU is the production of oxygen from lunar regolith, as it
can sustain human life and fuel space vehicles. Lunar min-
erals, comprising about 40% oxygen by mass, offer a rich
resource for this purpose (French et al., 1991). Utilising
space materials for water, fuel, and building supplies could
significantly reduce the launch mass and overall cost of
space missions.
Mineral beneficiation employs physical property dif-
ferences like density, surface chemistry, or electromagnetic
characteristics for separation (Wills &Finch, 2015 Rasera
2020). Dry processing techniques have been considered
for several mineral processing applications at lab- and
pilot-scale (Wills &Finch, 2015 Kelly and Spottiswood,
1989a, b, c Manouchehri et al., 2000a, b Trigwell et al.,
2003 Dwari et al., 2009 Bittner et al., 2014 Bilici et al.,
2011 Brands et al., 2001 Ballantyne &Holtham, 2010,
2014 Ireland 2010a, b, 2012 Ireland &Nicholson, 2011
Lawver 1973 Dwari et al., 2007). However, industrial-scale
dry processing technologies for terrestrial applications have
been limited to the use of high-tension roll separators for
the separation of ilmenite and rutile from zircon in beach
sands operations (Bittner et al., 2014 Dwari 2007 Wills
&Finch, 2015 Lawver 1973). For the majority of mining
applications, water-driven technologies, such as froth flota-
tion and spiral concentrators, have been favoured (Wills &
Finch, 2015).
Tribocharging, the frictional imparting of electrostatic
charge, is a millennia-old phenomenon (Lacks 2012),
yet its underlying mechanisms remain elusive (Lacks &
Levandovsky, 2007 Waitukaitis et al., 2014 Zhao et
al., 2003). Factors influencing charge transfer and reten-
tion include humidity, temperature, impact velocity, and
Optimising Tribocharger Designs for Separating Granular
Material Using the Discrete Element Method
Joshua N. Rasera, Jan J. Cilliers
Imperial College London
Kathryn Hadler
European Space Resources Innovation Centre
ABSTRACT: The optimisation of tribochargers using the discrete element method for the separating granular
materials, essential for dry mineral beneficiation, is studied. Various tribocharger designs are compared an
optimum is identified. The suitability of the design for charging other materials is considered. We extend our
analysis to simulate the conditions on the Moon, adapting the tribocharger design its unique environment.
We highlight the versatility of our modelling approach and its potential for mineral processing on Earth and
in space, particularly in the context of space resource utilisation. We provide insights into the adaptability and
effectiveness of tribocharging technologies under diverse conditions.
INTRODUCTION
Space Resource Utilisation (SRU) is integral to human
exploration and habitation of space. A critical first step for
SRU is the production of oxygen from lunar regolith, as it
can sustain human life and fuel space vehicles. Lunar min-
erals, comprising about 40% oxygen by mass, offer a rich
resource for this purpose (French et al., 1991). Utilising
space materials for water, fuel, and building supplies could
significantly reduce the launch mass and overall cost of
space missions.
Mineral beneficiation employs physical property dif-
ferences like density, surface chemistry, or electromagnetic
characteristics for separation (Wills &Finch, 2015 Rasera
2020). Dry processing techniques have been considered
for several mineral processing applications at lab- and
pilot-scale (Wills &Finch, 2015 Kelly and Spottiswood,
1989a, b, c Manouchehri et al., 2000a, b Trigwell et al.,
2003 Dwari et al., 2009 Bittner et al., 2014 Bilici et al.,
2011 Brands et al., 2001 Ballantyne &Holtham, 2010,
2014 Ireland 2010a, b, 2012 Ireland &Nicholson, 2011
Lawver 1973 Dwari et al., 2007). However, industrial-scale
dry processing technologies for terrestrial applications have
been limited to the use of high-tension roll separators for
the separation of ilmenite and rutile from zircon in beach
sands operations (Bittner et al., 2014 Dwari 2007 Wills
&Finch, 2015 Lawver 1973). For the majority of mining
applications, water-driven technologies, such as froth flota-
tion and spiral concentrators, have been favoured (Wills &
Finch, 2015).
Tribocharging, the frictional imparting of electrostatic
charge, is a millennia-old phenomenon (Lacks 2012),
yet its underlying mechanisms remain elusive (Lacks &
Levandovsky, 2007 Waitukaitis et al., 2014 Zhao et
al., 2003). Factors influencing charge transfer and reten-
tion include humidity, temperature, impact velocity, and