XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 357
Geared DC Motor, 238-9759) and three variations (15°,
30° and 45°) were created, and two sets of experiments were
conducted with the 30° cone on 0° inclination (i.e., spin-
ning horizontally) to test the separation principle. Some of
the experiments were recorded with a Chronos 1.4 High-
Speed Camera.
EXPERIMENTS
Tests used a mixture of LHS-1 simulant with additional
anorthosite particles of mostly 1 mm sizes, with the cone
spinning at approximately 400, 600 and 800 RPM and
3 trials each. The particles were dried in an oven at 100
degrees for one hour to remove moisture, then sieved into
1 mm and 1 mm fractions and mixed 50:50 by mass
(2 g each) for each trial as shown in Figure 7. After each
trial, the particles in each plate were sieved through a 1 mm
sieve, and the masses of each size fraction was recorded.
Each test was repeated 3 times and the 95% confidence
intervals calculated.
For this system, the target of the separation is to remove
particles +1 mm. As there was a defined target size for par-
ticle removal, analysis of the efficiency of the size classifica-
tion can be considered as analogous to barrier methods such
as screens. The efficiency has been calculated by subtracting
the recovery of the –1 mm particles from the recovery of
the +1 mm particles in a given zone or ring, in line with
Wills &Finch (2015). Recovery of particles is calculated as
in Equation 1:
R F f
C c
#
#=(1)
where,
C =total mass of particles collected on each plate
c =mass fraction (grade) of target size (coarse or
fine) per plate
F =total mass in the feed
f =mass fraction (grade) of target size (coarse or
fine) in the feed
In addition, mass distribution of particles around the col-
lections plates was determined.
RESULTS AND DISCUSSIONS
The results for the separation efficiency and mass distribu-
tion by zone and ring are shown in Figure 8 and Figure 9,
respectively. In Figure 8, it can be seen that in Zone 1, the
radial slice closest to the feed position, there is a large posi-
tive difference between the recoveries of the +1 mm and
–1 mm particles, whilst in the following radial positions,
there is a greater recovery of fine particles. There is little dif-
ference with rotational speed of the cone. The results sug-
gest that a good separation of particles by size is obtained
by radial position. On the other hand, an increase in dis-
tance of the collection plate from the cone results in higher
coarse recoveries, but closest to the cone shows a string
rotational speed dependence. This is likely to be linked to
the fine particles sticking to the cone at low speeds. Overall,
considering the distribution of particles by radial position
exhibits greater size separation performance compared to
be distance.
When combined with the mass distribution, Figure 9,
approximately 80% of the mass is collected in the two
Figure 7. Still from a high-speed video of particles landing on the rotating cone (LHS). Distribution of
particles in the collection bins after a test (RHS)
Geared DC Motor, 238-9759) and three variations (15°,
30° and 45°) were created, and two sets of experiments were
conducted with the 30° cone on 0° inclination (i.e., spin-
ning horizontally) to test the separation principle. Some of
the experiments were recorded with a Chronos 1.4 High-
Speed Camera.
EXPERIMENTS
Tests used a mixture of LHS-1 simulant with additional
anorthosite particles of mostly 1 mm sizes, with the cone
spinning at approximately 400, 600 and 800 RPM and
3 trials each. The particles were dried in an oven at 100
degrees for one hour to remove moisture, then sieved into
1 mm and 1 mm fractions and mixed 50:50 by mass
(2 g each) for each trial as shown in Figure 7. After each
trial, the particles in each plate were sieved through a 1 mm
sieve, and the masses of each size fraction was recorded.
Each test was repeated 3 times and the 95% confidence
intervals calculated.
For this system, the target of the separation is to remove
particles +1 mm. As there was a defined target size for par-
ticle removal, analysis of the efficiency of the size classifica-
tion can be considered as analogous to barrier methods such
as screens. The efficiency has been calculated by subtracting
the recovery of the –1 mm particles from the recovery of
the +1 mm particles in a given zone or ring, in line with
Wills &Finch (2015). Recovery of particles is calculated as
in Equation 1:
R F f
C c
#
#=(1)
where,
C =total mass of particles collected on each plate
c =mass fraction (grade) of target size (coarse or
fine) per plate
F =total mass in the feed
f =mass fraction (grade) of target size (coarse or
fine) in the feed
In addition, mass distribution of particles around the col-
lections plates was determined.
RESULTS AND DISCUSSIONS
The results for the separation efficiency and mass distribu-
tion by zone and ring are shown in Figure 8 and Figure 9,
respectively. In Figure 8, it can be seen that in Zone 1, the
radial slice closest to the feed position, there is a large posi-
tive difference between the recoveries of the +1 mm and
–1 mm particles, whilst in the following radial positions,
there is a greater recovery of fine particles. There is little dif-
ference with rotational speed of the cone. The results sug-
gest that a good separation of particles by size is obtained
by radial position. On the other hand, an increase in dis-
tance of the collection plate from the cone results in higher
coarse recoveries, but closest to the cone shows a string
rotational speed dependence. This is likely to be linked to
the fine particles sticking to the cone at low speeds. Overall,
considering the distribution of particles by radial position
exhibits greater size separation performance compared to
be distance.
When combined with the mass distribution, Figure 9,
approximately 80% of the mass is collected in the two
Figure 7. Still from a high-speed video of particles landing on the rotating cone (LHS). Distribution of
particles in the collection bins after a test (RHS)