354 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
minerals that were found in lunar regolith and mixed to a
certain proportion. However, like many other simulants,
LHS-1 only contain particles up to 1 mm. For the experi-
ments conducted in this study, the LHS-1 simulant was
used, but mixed with additional 1 mm anorthosite par-
ticles from a separate source.
Equipment
To develop a size classification technology that can operate
on the lunar surface (i.e., under low gravity and with no
operating fluids), we consider forces that can be applied
to impart different motion on particles of different size.
Barrier methods such as screens are excluded due to the risk
of blinding and wear. Centrifugal forces and vibration are
both suitable for the lunar environment. Here we present
the development of a centrifugal-based size separator and
use it to demonstrate the challenges of designing processes
for lunar ISRU.
The design of the centrifugal size separator is based
on previous works (Berggren et al., 2011 Mitchell et al.,
2023). A centrifuge-based size classifier was first developed
by Berggren et al. (2011) using a large rotating cone to dis-
tribute simulant particles into different particle size ranges.
The particles were dropped onto the cone, which has a 30°
angle from horizontal, through a vibratory feeder. As the
particles come into contact with the surface of the cone,
they exhibit different trajectories based on their particle
sizes. In general, larger particles fall down the cone first,
while the finer particles retain longer on the cone due to
friction and a larger surface area to mass ratio, and travel
along the cone’s rotation at a slower speed (Figure 4a). As
seen in Figure 4b, coarser particles would concentrate closer
to the initial feeding position, while finer particles can be
collected further down the cone’s rotational path. After
the initial phase of testing concept, the authors developed
a second phase with a larger cone with a different surface
Figure 3. Particle size distribution by weight of selected Apollo samples. Data obtained from the Lunar
sourcebook, Chapter 9 (Carrier et al., 1991). Particles larger than 1 mm or even 1 cm could take up more
than 10 wt% in most of these samples
minerals that were found in lunar regolith and mixed to a
certain proportion. However, like many other simulants,
LHS-1 only contain particles up to 1 mm. For the experi-
ments conducted in this study, the LHS-1 simulant was
used, but mixed with additional 1 mm anorthosite par-
ticles from a separate source.
Equipment
To develop a size classification technology that can operate
on the lunar surface (i.e., under low gravity and with no
operating fluids), we consider forces that can be applied
to impart different motion on particles of different size.
Barrier methods such as screens are excluded due to the risk
of blinding and wear. Centrifugal forces and vibration are
both suitable for the lunar environment. Here we present
the development of a centrifugal-based size separator and
use it to demonstrate the challenges of designing processes
for lunar ISRU.
The design of the centrifugal size separator is based
on previous works (Berggren et al., 2011 Mitchell et al.,
2023). A centrifuge-based size classifier was first developed
by Berggren et al. (2011) using a large rotating cone to dis-
tribute simulant particles into different particle size ranges.
The particles were dropped onto the cone, which has a 30°
angle from horizontal, through a vibratory feeder. As the
particles come into contact with the surface of the cone,
they exhibit different trajectories based on their particle
sizes. In general, larger particles fall down the cone first,
while the finer particles retain longer on the cone due to
friction and a larger surface area to mass ratio, and travel
along the cone’s rotation at a slower speed (Figure 4a). As
seen in Figure 4b, coarser particles would concentrate closer
to the initial feeding position, while finer particles can be
collected further down the cone’s rotational path. After
the initial phase of testing concept, the authors developed
a second phase with a larger cone with a different surface
Figure 3. Particle size distribution by weight of selected Apollo samples. Data obtained from the Lunar
sourcebook, Chapter 9 (Carrier et al., 1991). Particles larger than 1 mm or even 1 cm could take up more
than 10 wt% in most of these samples