XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 3279
in the fine fraction. This is confirmed by the results of the
ICP-AES measurements shown in Table 1. It can be seen
that the fractions larger than 200 µm are all depleted in
perovskites and the two fine fractions show an enrichment.
Especially the finest fraction shows a clear enrichment in
perovskites from 5% in the original cell to over 36%. This
means that a pre-concentrate of perovskites can already be
obtained by comminution.
For ultrasonic decoating, the two coarse fractions with
a particle size x 1 mm and 315 µm x ≤ 1 mm were
examined. The sample was weighed after every 5 seconds
and the cumulative detached mass ratio was calculated. The
results for the cumulative detached mass ratio are shown
in Figure 3a. A similar plot is seen for both particle size
fractions. The cumulative detached mass ratio rises sharply
to about 1.5 %in the first 10 s and then rises with a lower
slope almost linearly to about 2 %.The cumulative detached
mass ratio of the particles in the 315 µm x ≤ 1 mm size
fraction is above that of the coarser fraction. In the first
five seconds of stressing the difference increases to about
0.5 %,then decreases to about 0.3 %by 10 seconds, and
then remains almost parallel with a constant spacing. In
addition to the random deviation caused by sampling, the
area available for decoating could also have an influence.
Both samples were taken according to their mass. However,
the stress of the decoating process is mainly on the surface,
so a higher surface area of the total sample may also result
in a higher detachment of surface particles. Since smaller
particles have a higher surface area than larger ones, this
may be a reason for the higher cumulative detached mass
ratio in the 315 µm x ≤ 1 mm fraction compared to the
fraction 1 mm.
Figure 3b and Figure 3c show the particles before and
after 30 s of ultrasound exposure, respectively. The black
material corresponds to the perovskite material. Even before
ultrasonic stress, it can be seen that the perovskite layer has
been partially detached from the cell particles, exposing
the underlying electrolyte. The perovskites appear to be
0
10
20
30
40
50
60
70
80
90
100
0.1 1 10
Particle size x /mm
Sieving analysis Image analysis
Figure 2. Particle size distribution determined by sieving analysis of the
whole cell after comminution and for the fraction 1 mm determined by
static image analysis
Table 1. Material composition of the cell and the size fractions after sieving
Material
Mass Fraction in wt.-%
Cell ≤ 100 µm 100 µm x ≤ 200 µm 200 µm x ≤ 315 µm 315 µm x ≤ 1 mm 1 mm
Perovskite 5.13 36.94 7.33 2.58 0.92 1.33
Nickel oxide 51.02 33.75 52.74 56.10 53.78 51.84
Other 43.85 29.31 39.93 41.32 45.3 46.83
Cumulative
sum
Q 3 /
%
in the fine fraction. This is confirmed by the results of the
ICP-AES measurements shown in Table 1. It can be seen
that the fractions larger than 200 µm are all depleted in
perovskites and the two fine fractions show an enrichment.
Especially the finest fraction shows a clear enrichment in
perovskites from 5% in the original cell to over 36%. This
means that a pre-concentrate of perovskites can already be
obtained by comminution.
For ultrasonic decoating, the two coarse fractions with
a particle size x 1 mm and 315 µm x ≤ 1 mm were
examined. The sample was weighed after every 5 seconds
and the cumulative detached mass ratio was calculated. The
results for the cumulative detached mass ratio are shown
in Figure 3a. A similar plot is seen for both particle size
fractions. The cumulative detached mass ratio rises sharply
to about 1.5 %in the first 10 s and then rises with a lower
slope almost linearly to about 2 %.The cumulative detached
mass ratio of the particles in the 315 µm x ≤ 1 mm size
fraction is above that of the coarser fraction. In the first
five seconds of stressing the difference increases to about
0.5 %,then decreases to about 0.3 %by 10 seconds, and
then remains almost parallel with a constant spacing. In
addition to the random deviation caused by sampling, the
area available for decoating could also have an influence.
Both samples were taken according to their mass. However,
the stress of the decoating process is mainly on the surface,
so a higher surface area of the total sample may also result
in a higher detachment of surface particles. Since smaller
particles have a higher surface area than larger ones, this
may be a reason for the higher cumulative detached mass
ratio in the 315 µm x ≤ 1 mm fraction compared to the
fraction 1 mm.
Figure 3b and Figure 3c show the particles before and
after 30 s of ultrasound exposure, respectively. The black
material corresponds to the perovskite material. Even before
ultrasonic stress, it can be seen that the perovskite layer has
been partially detached from the cell particles, exposing
the underlying electrolyte. The perovskites appear to be
0
10
20
30
40
50
60
70
80
90
100
0.1 1 10
Particle size x /mm
Sieving analysis Image analysis
Figure 2. Particle size distribution determined by sieving analysis of the
whole cell after comminution and for the fraction 1 mm determined by
static image analysis
Table 1. Material composition of the cell and the size fractions after sieving
Material
Mass Fraction in wt.-%
Cell ≤ 100 µm 100 µm x ≤ 200 µm 200 µm x ≤ 315 µm 315 µm x ≤ 1 mm 1 mm
Perovskite 5.13 36.94 7.33 2.58 0.92 1.33
Nickel oxide 51.02 33.75 52.74 56.10 53.78 51.84
Other 43.85 29.31 39.93 41.32 45.3 46.83
Cumulative
sum
Q 3 /
%